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<!doctype html><html lang="en-GB-oxendict">
<head><meta name="viewport" content="width=device-width, initial-scale=1"><meta charset="utf-8"><meta property="og:image" content="https://tc39.es/ecmarkup/ecma-logo.png"><meta property="og:title" content="ECMAScript® 2026 Language&nbsp;Specification"><meta property="og:description" content="Introduction
This Ecma Standard defines the ECMAScript 2026 Language. It is the seventeenth edition of the ECMAScript Language Specification. ECMAScript is based on several originating technologies, the most well-known being JavaScript (Netscape) and JScript (Microsoft). The language was invent">
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<title>ECMAScript® 2026 Language&nbsp;Specification</title><script src="../assets/js/multipage.js?cache=Wu2V1pj2" defer=""></script><script src="../assets/js/ecmarkup.js?cache=BPFBckdu" defer=""></script><link rel="canonical" href="../#sec-control-abstraction-objects"></head>
<body><div id="menu"><div id="menu-search"><input type="text" id="menu-search-box" placeholder="Search..."><div id="menu-search-results" class="inactive"></div></div><div id="menu-pins"><div class="menu-pane-header">Pins<button class="unpin-all">clear</button></div><ul id="menu-pins-list"></ul></div><div class="menu-pane-header">Table of Contents</div><div id="menu-toc"><ol class="toc"><li><span class="item-toggle-none"></span><a href="./#sec-intro" title="Introduction">Introduction</a></li><li><span class="item-toggle-none"></span><a href="scope.html#sec-scope" title="Scope"><span class="secnum">1</span> Scope</a></li><li><span class="item-toggle">+</span><a href="conformance.html#sec-conformance" title="Conformance"><span class="secnum">2</span> Conformance</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="conformance.html#sec-conformance-normative-optional" title="Example Normative Optional Clause Heading"><span class="secnum">2.1</span> Example Normative Optional Clause Heading</a></li><li><span class="item-toggle-none"></span><a href="conformance.html#sec-conformance-legacy" title="Example Legacy Clause Heading"><span class="secnum">2.2</span> Example Legacy Clause Heading</a></li><li><span class="item-toggle-none"></span><a href="conformance.html#sec-conformance-legacy-normative-optional" title="Example Legacy Normative Optional Clause Heading"><span class="secnum">2.3</span> Example Legacy Normative Optional Clause Heading</a></li></ol></li><li><span class="item-toggle-none"></span><a href="normative-references.html#sec-normative-references" title="Normative References"><span class="secnum">3</span> Normative References</a></li><li><span class="item-toggle">+</span><a href="overview.html#sec-overview" title="Overview"><span class="secnum">4</span> Overview</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="overview.html#sec-web-scripting" title="Web Scripting"><span class="secnum">4.1</span> Web Scripting</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-hosts-and-implementations" title="Hosts and Implementations"><span class="secnum">4.2</span> Hosts and Implementations</a></li><li><span class="item-toggle">+</span><a href="overview.html#sec-ecmascript-overview" title="ECMAScript Overview"><span class="secnum">4.3</span> ECMAScript Overview</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="overview.html#sec-objects" title="Objects"><span class="secnum">4.3.1</span> Objects</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-strict-variant-of-ecmascript" title="The Strict Variant of ECMAScript"><span class="secnum">4.3.2</span> The Strict Variant of ECMAScript</a></li></ol></li><li><span class="item-toggle">+</span><a href="overview.html#sec-terms-and-definitions" title="Terms and Definitions"><span class="secnum">4.4</span> Terms and Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-implementation-approximated" title="implementation-approximated"><span class="secnum">4.4.1</span> implementation-approximated</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-implementation-defined" title="implementation-defined"><span class="secnum">4.4.2</span> implementation-defined</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-host-defined" title="host-defined"><span class="secnum">4.4.3</span> host-defined</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-type" title="type"><span class="secnum">4.4.4</span> type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-primitive-value" title="primitive value"><span class="secnum">4.4.5</span> primitive value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-object" title="object"><span class="secnum">4.4.6</span> object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-constructor" title="constructor"><span class="secnum">4.4.7</span> constructor</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-prototype" title="prototype"><span class="secnum">4.4.8</span> prototype</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-ordinary-object" title="ordinary object"><span class="secnum">4.4.9</span> ordinary object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-exotic-object" title="exotic object"><span class="secnum">4.4.10</span> exotic object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-standard-object" title="standard object"><span class="secnum">4.4.11</span> standard object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-built-in-object" title="built-in object"><span class="secnum">4.4.12</span> built-in object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-undefined-value" title="undefined value"><span class="secnum">4.4.13</span> undefined value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-undefined-type" title="Undefined type"><span class="secnum">4.4.14</span> Undefined type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-null-value" title="null value"><span class="secnum">4.4.15</span> null value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-null-type" title="Null type"><span class="secnum">4.4.16</span> Null type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-boolean-value" title="Boolean value"><span class="secnum">4.4.17</span> Boolean value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-boolean-type" title="Boolean type"><span class="secnum">4.4.18</span> Boolean type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-boolean-object" title="Boolean object"><span class="secnum">4.4.19</span> Boolean object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-string-value" title="String value"><span class="secnum">4.4.20</span> String value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-string-type" title="String type"><span class="secnum">4.4.21</span> String type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-string-object" title="String object"><span class="secnum">4.4.22</span> String object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-number-value" title="Number value"><span class="secnum">4.4.23</span> Number value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-number-type" title="Number type"><span class="secnum">4.4.24</span> Number type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-number-object" title="Number object"><span class="secnum">4.4.25</span> Number object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-infinity" title="Infinity"><span class="secnum">4.4.26</span> Infinity</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-nan" title="NaN"><span class="secnum">4.4.27</span> NaN</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-bigint-value" title="BigInt value"><span class="secnum">4.4.28</span> BigInt value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-bigint-type" title="BigInt type"><span class="secnum">4.4.29</span> BigInt type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-bigint-object" title="BigInt object"><span class="secnum">4.4.30</span> BigInt object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-symbol-value" title="Symbol value"><span class="secnum">4.4.31</span> Symbol value</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-symbol-type" title="Symbol type"><span class="secnum">4.4.32</span> Symbol type</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-symbol-object" title="Symbol object"><span class="secnum">4.4.33</span> Symbol object</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-terms-and-definitions-function" title="function"><span class="secnum">4.4.34</span> function</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-built-in-function" title="built-in function"><span class="secnum">4.4.35</span> built-in function</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-built-in-constructor" title="built-in constructor"><span class="secnum">4.4.36</span> built-in constructor</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-property" title="property"><span class="secnum">4.4.37</span> property</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-method" title="method"><span class="secnum">4.4.38</span> method</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-built-in-method" title="built-in method"><span class="secnum">4.4.39</span> built-in method</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-attribute" title="attribute"><span class="secnum">4.4.40</span> attribute</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-own-property" title="own property"><span class="secnum">4.4.41</span> own property</a></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-inherited-property" title="inherited property"><span class="secnum">4.4.42</span> inherited property</a></li></ol></li><li><span class="item-toggle-none"></span><a href="overview.html#sec-organization-of-this-specification" title="Organization of This Specification"><span class="secnum">4.5</span> Organization of This Specification</a></li></ol></li><li><span class="item-toggle">+</span><a href="notational-conventions.html#sec-notational-conventions" title="Notational Conventions"><span class="secnum">5</span> Notational Conventions</a><ol class="toc"><li><span class="item-toggle">+</span><a href="notational-conventions.html#sec-syntactic-and-lexical-grammars" title="Syntactic and Lexical Grammars"><span class="secnum">5.1</span> Syntactic and Lexical Grammars</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-context-free-grammars" title="Context-Free Grammars"><span class="secnum">5.1.1</span> Context-Free Grammars</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-lexical-and-regexp-grammars" title="The Lexical and RegExp Grammars"><span class="secnum">5.1.2</span> The Lexical and RegExp Grammars</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-numeric-string-grammar" title="The Numeric String Grammar"><span class="secnum">5.1.3</span> The Numeric String Grammar</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-syntactic-grammar" title="The Syntactic Grammar"><span class="secnum">5.1.4</span> The Syntactic Grammar</a></li><li><span class="item-toggle">+</span><a href="notational-conventions.html#sec-grammar-notation" title="Grammar Notation"><span class="secnum">5.1.5</span> Grammar Notation</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-terminal-symbols" title="Terminal Symbols"><span class="secnum">5.1.5.1</span> Terminal Symbols</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-nonterminal-symbols-and-productions" title="Nonterminal Symbols and Productions"><span class="secnum">5.1.5.2</span> Nonterminal Symbols and Productions</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-optional-symbols" title="Optional Symbols"><span class="secnum">5.1.5.3</span> Optional Symbols</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-grammatical-parameters" title="Grammatical Parameters"><span class="secnum">5.1.5.4</span> Grammatical Parameters</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-one-of" title="one of"><span class="secnum">5.1.5.5</span> one of</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-empty" title="[empty]"><span class="secnum">5.1.5.6</span> [empty]</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-lookahead-restrictions" title="Lookahead Restrictions"><span class="secnum">5.1.5.7</span> Lookahead Restrictions</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-no-lineterminator-here" title="[no LineTerminator here]"><span class="secnum">5.1.5.8</span> [no <emu-nt>LineTerminator</emu-nt> here]</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-but-not" title="but not"><span class="secnum">5.1.5.9</span> but not</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-descriptive-phrases" title="Descriptive Phrases"><span class="secnum">5.1.5.10</span> Descriptive Phrases</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="notational-conventions.html#sec-algorithm-conventions" title="Algorithm Conventions"><span class="secnum">5.2</span> Algorithm Conventions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-evaluation-order" title="Evaluation Order"><span class="secnum">5.2.1</span> Evaluation Order</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-algorithm-conventions-abstract-operations" title="Abstract Operations"><span class="secnum">5.2.2</span> Abstract Operations</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations" title="Syntax-Directed Operations"><span class="secnum">5.2.3</span> Syntax-Directed Operations</a></li><li><span class="item-toggle">+</span><a href="notational-conventions.html#sec-runtime-semantics" title="Runtime Semantics"><span class="secnum">5.2.4</span> Runtime Semantics</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-completion-ao" title="Completion ( completionRecord )"><span class="secnum">5.2.4.1</span> Completion ( <var>completionRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-throw-an-exception" title="Throw an Exception"><span class="secnum">5.2.4.2</span> Throw an Exception</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-shorthands-for-unwrapping-completion-records" title="Shorthands for Unwrapping Completion Records"><span class="secnum">5.2.4.3</span> Shorthands for Unwrapping Completion Records</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-implicit-normal-completion" title="Implicit Normal Completion"><span class="secnum">5.2.4.4</span> Implicit Normal Completion</a></li></ol></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-static-semantic-rules" title="Static Semantics"><span class="secnum">5.2.5</span> Static Semantics</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-mathematical-operations" title="Mathematical Operations"><span class="secnum">5.2.6</span> Mathematical Operations</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-value-notation" title="Value Notation"><span class="secnum">5.2.7</span> Value Notation</a></li><li><span class="item-toggle-none"></span><a href="notational-conventions.html#sec-identity" title="Identity"><span class="secnum">5.2.8</span> Identity</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-data-types-and-values" title="ECMAScript Data Types and Values"><span class="secnum">6</span> ECMAScript Data Types and Values</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types" title="ECMAScript Language Types"><span class="secnum">6.1</span> ECMAScript Language Types</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-undefined-type" title="The Undefined Type"><span class="secnum">6.1.1</span> The Undefined Type</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-null-type" title="The Null Type"><span class="secnum">6.1.2</span> The Null Type</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-boolean-type" title="The Boolean Type"><span class="secnum">6.1.3</span> The Boolean Type</a></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-string-type" title="The String Type"><span class="secnum">6.1.4</span> The String Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-stringindexof" title="StringIndexOf ( string, searchValue, fromIndex )"><span class="secnum">6.1.4.1</span> StringIndexOf ( <var>string</var>, <var>searchValue</var>, <var>fromIndex</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-stringlastindexof" title="StringLastIndexOf ( string, searchValue, fromIndex )"><span class="secnum">6.1.4.2</span> StringLastIndexOf ( <var>string</var>, <var>searchValue</var>, <var>fromIndex</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-symbol-type" title="The Symbol Type"><span class="secnum">6.1.5</span> The Symbol Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols" title="Well-Known Symbols"><span class="secnum">6.1.5.1</span> Well-Known Symbols</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-numeric-types" title="Numeric Types"><span class="secnum">6.1.6</span> Numeric Types</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-number-type" title="The Number Type"><span class="secnum">6.1.6.1</span> The Number Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-unaryMinus" title="Number::unaryMinus ( x )"><span class="secnum">6.1.6.1.1</span> Number::unaryMinus ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-bitwiseNOT" title="Number::bitwiseNOT ( x )"><span class="secnum">6.1.6.1.2</span> Number::bitwiseNOT ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-exponentiate" title="Number::exponentiate ( base, exponent )"><span class="secnum">6.1.6.1.3</span> Number::exponentiate ( <var>base</var>, <var>exponent</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-multiply" title="Number::multiply ( x, y )"><span class="secnum">6.1.6.1.4</span> Number::multiply ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-divide" title="Number::divide ( x, y )"><span class="secnum">6.1.6.1.5</span> Number::divide ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-remainder" title="Number::remainder ( n, d )"><span class="secnum">6.1.6.1.6</span> Number::remainder ( <var>n</var>, <var>d</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-add" title="Number::add ( x, y )"><span class="secnum">6.1.6.1.7</span> Number::add ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-subtract" title="Number::subtract ( x, y )"><span class="secnum">6.1.6.1.8</span> Number::subtract ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-leftShift" title="Number::leftShift ( x, y )"><span class="secnum">6.1.6.1.9</span> Number::leftShift ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-signedRightShift" title="Number::signedRightShift ( x, y )"><span class="secnum">6.1.6.1.10</span> Number::signedRightShift ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-unsignedRightShift" title="Number::unsignedRightShift ( x, y )"><span class="secnum">6.1.6.1.11</span> Number::unsignedRightShift ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-lessThan" title="Number::lessThan ( x, y )"><span class="secnum">6.1.6.1.12</span> Number::lessThan ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-equal" title="Number::equal ( x, y )"><span class="secnum">6.1.6.1.13</span> Number::equal ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-sameValue" title="Number::sameValue ( x, y )"><span class="secnum">6.1.6.1.14</span> Number::sameValue ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-sameValueZero" title="Number::sameValueZero ( x, y )"><span class="secnum">6.1.6.1.15</span> Number::sameValueZero ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numberbitwiseop" title="NumberBitwiseOp ( op, x, y )"><span class="secnum">6.1.6.1.16</span> NumberBitwiseOp ( <var>op</var>, <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-bitwiseAND" title="Number::bitwiseAND ( x, y )"><span class="secnum">6.1.6.1.17</span> Number::bitwiseAND ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-bitwiseXOR" title="Number::bitwiseXOR ( x, y )"><span class="secnum">6.1.6.1.18</span> Number::bitwiseXOR ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-bitwiseOR" title="Number::bitwiseOR ( x, y )"><span class="secnum">6.1.6.1.19</span> Number::bitwiseOR ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-number-tostring" title="Number::toString ( x, radix )"><span class="secnum">6.1.6.1.20</span> Number::toString ( <var>x</var>, <var>radix</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-bigint-type" title="The BigInt Type"><span class="secnum">6.1.6.2</span> The BigInt Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-unaryMinus" title="BigInt::unaryMinus ( x )"><span class="secnum">6.1.6.2.1</span> BigInt::unaryMinus ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-bitwiseNOT" title="BigInt::bitwiseNOT ( x )"><span class="secnum">6.1.6.2.2</span> BigInt::bitwiseNOT ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-exponentiate" title="BigInt::exponentiate ( base, exponent )"><span class="secnum">6.1.6.2.3</span> BigInt::exponentiate ( <var>base</var>, <var>exponent</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-multiply" title="BigInt::multiply ( x, y )"><span class="secnum">6.1.6.2.4</span> BigInt::multiply ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-divide" title="BigInt::divide ( x, y )"><span class="secnum">6.1.6.2.5</span> BigInt::divide ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-remainder" title="BigInt::remainder ( n, d )"><span class="secnum">6.1.6.2.6</span> BigInt::remainder ( <var>n</var>, <var>d</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-add" title="BigInt::add ( x, y )"><span class="secnum">6.1.6.2.7</span> BigInt::add ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-subtract" title="BigInt::subtract ( x, y )"><span class="secnum">6.1.6.2.8</span> BigInt::subtract ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-leftShift" title="BigInt::leftShift ( x, y )"><span class="secnum">6.1.6.2.9</span> BigInt::leftShift ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-signedRightShift" title="BigInt::signedRightShift ( x, y )"><span class="secnum">6.1.6.2.10</span> BigInt::signedRightShift ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-unsignedRightShift" title="BigInt::unsignedRightShift ( x, y )"><span class="secnum">6.1.6.2.11</span> BigInt::unsignedRightShift ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-lessThan" title="BigInt::lessThan ( x, y )"><span class="secnum">6.1.6.2.12</span> BigInt::lessThan ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-equal" title="BigInt::equal ( x, y )"><span class="secnum">6.1.6.2.13</span> BigInt::equal ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-binaryand" title="BinaryAnd ( x, y )"><span class="secnum">6.1.6.2.14</span> BinaryAnd ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-binaryor" title="BinaryOr ( x, y )"><span class="secnum">6.1.6.2.15</span> BinaryOr ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-binaryxor" title="BinaryXor ( x, y )"><span class="secnum">6.1.6.2.16</span> BinaryXor ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-bigintbitwiseop" title="BigIntBitwiseOp ( op, x, y )"><span class="secnum">6.1.6.2.17</span> BigIntBitwiseOp ( <var>op</var>, <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-bitwiseAND" title="BigInt::bitwiseAND ( x, y )"><span class="secnum">6.1.6.2.18</span> BigInt::bitwiseAND ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-bitwiseXOR" title="BigInt::bitwiseXOR ( x, y )"><span class="secnum">6.1.6.2.19</span> BigInt::bitwiseXOR ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-bitwiseOR" title="BigInt::bitwiseOR ( x, y )"><span class="secnum">6.1.6.2.20</span> BigInt::bitwiseOR ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-numeric-types-bigint-tostring" title="BigInt::toString ( x, radix )"><span class="secnum">6.1.6.2.21</span> BigInt::toString ( <var>x</var>, <var>radix</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-object-type" title="The Object Type"><span class="secnum">6.1.7</span> The Object Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-property-attributes" title="Property Attributes"><span class="secnum">6.1.7.1</span> Property Attributes</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-object-internal-methods-and-internal-slots" title="Object Internal Methods and Internal Slots"><span class="secnum">6.1.7.2</span> Object Internal Methods and Internal Slots</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-invariants-of-the-essential-internal-methods" title="Invariants of the Essential Internal Methods"><span class="secnum">6.1.7.3</span> Invariants of the Essential Internal Methods</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-well-known-intrinsic-objects" title="Well-Known Intrinsic Objects"><span class="secnum">6.1.7.4</span> Well-Known Intrinsic Objects</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-ecmascript-specification-types" title="ECMAScript Specification Types"><span class="secnum">6.2</span> ECMAScript Specification Types</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-enum-specification-type" title="The Enum Specification Type"><span class="secnum">6.2.1</span> The Enum Specification Type</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type" title="The List and Record Specification Types"><span class="secnum">6.2.2</span> The List and Record Specification Types</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-set-and-relation-specification-type" title="The Set and Relation Specification Types"><span class="secnum">6.2.3</span> The Set and Relation Specification Types</a></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type" title="The Completion Record Specification Type"><span class="secnum">6.2.4</span> The Completion Record Specification Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-normalcompletion" title="NormalCompletion ( value )"><span class="secnum">6.2.4.1</span> NormalCompletion ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-throwcompletion" title="ThrowCompletion ( value )"><span class="secnum">6.2.4.2</span> ThrowCompletion ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-returncompletion" title="ReturnCompletion ( value )"><span class="secnum">6.2.4.3</span> ReturnCompletion ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-updateempty" title="UpdateEmpty ( completionRecord, value )"><span class="secnum">6.2.4.4</span> UpdateEmpty ( <var>completionRecord</var>, <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-reference-record-specification-type" title="The Reference Record Specification Type"><span class="secnum">6.2.5</span> The Reference Record Specification Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-ispropertyreference" title="IsPropertyReference ( V )"><span class="secnum">6.2.5.1</span> IsPropertyReference ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-isunresolvablereference" title="IsUnresolvableReference ( V )"><span class="secnum">6.2.5.2</span> IsUnresolvableReference ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-issuperreference" title="IsSuperReference ( V )"><span class="secnum">6.2.5.3</span> IsSuperReference ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-isprivatereference" title="IsPrivateReference ( V )"><span class="secnum">6.2.5.4</span> IsPrivateReference ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-getvalue" title="GetValue ( V )"><span class="secnum">6.2.5.5</span> GetValue ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-putvalue" title="PutValue ( V, W )"><span class="secnum">6.2.5.6</span> PutValue ( <var>V</var>, <var>W</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-getthisvalue" title="GetThisValue ( V )"><span class="secnum">6.2.5.7</span> GetThisValue ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-initializereferencedbinding" title="InitializeReferencedBinding ( V, W )"><span class="secnum">6.2.5.8</span> InitializeReferencedBinding ( <var>V</var>, <var>W</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-makeprivatereference" title="MakePrivateReference ( baseValue, privateIdentifier )"><span class="secnum">6.2.5.9</span> MakePrivateReference ( <var>baseValue</var>, <var>privateIdentifier</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-property-descriptor-specification-type" title="The Property Descriptor Specification Type"><span class="secnum">6.2.6</span> The Property Descriptor Specification Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-isaccessordescriptor" title="IsAccessorDescriptor ( Desc )"><span class="secnum">6.2.6.1</span> IsAccessorDescriptor ( <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-isdatadescriptor" title="IsDataDescriptor ( Desc )"><span class="secnum">6.2.6.2</span> IsDataDescriptor ( <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-isgenericdescriptor" title="IsGenericDescriptor ( Desc )"><span class="secnum">6.2.6.3</span> IsGenericDescriptor ( <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-frompropertydescriptor" title="FromPropertyDescriptor ( Desc )"><span class="secnum">6.2.6.4</span> FromPropertyDescriptor ( <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-topropertydescriptor" title="ToPropertyDescriptor ( Obj )"><span class="secnum">6.2.6.5</span> ToPropertyDescriptor ( <var>Obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-completepropertydescriptor" title="CompletePropertyDescriptor ( Desc )"><span class="secnum">6.2.6.6</span> CompletePropertyDescriptor ( <var>Desc</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-lexical-environment-and-environment-record-specification-types" title="The Environment Record Specification Type"><span class="secnum">6.2.7</span> The Environment Record Specification Type</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-abstract-closure" title="The Abstract Closure Specification Type"><span class="secnum">6.2.8</span> The Abstract Closure Specification Type</a></li><li><span class="item-toggle">+</span><a href="ecmascript-data-types-and-values.html#sec-data-blocks" title="Data Blocks"><span class="secnum">6.2.9</span> Data Blocks</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-createbytedatablock" title="CreateByteDataBlock ( size )"><span class="secnum">6.2.9.1</span> CreateByteDataBlock ( <var>size</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-createsharedbytedatablock" title="CreateSharedByteDataBlock ( size )"><span class="secnum">6.2.9.2</span> CreateSharedByteDataBlock ( <var>size</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-copydatablockbytes" title="CopyDataBlockBytes ( toBlock, toIndex, fromBlock, fromIndex, count )"><span class="secnum">6.2.9.3</span> CopyDataBlockBytes ( <var>toBlock</var>, <var>toIndex</var>, <var>fromBlock</var>, <var>fromIndex</var>, <var>count</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-privateelement-specification-type" title="The PrivateElement Specification Type"><span class="secnum">6.2.10</span> The PrivateElement Specification Type</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-classfielddefinition-record-specification-type" title="The ClassFieldDefinition Record Specification Type"><span class="secnum">6.2.11</span> The ClassFieldDefinition Record Specification Type</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-private-names" title="Private Names"><span class="secnum">6.2.12</span> Private Names</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-data-types-and-values.html#sec-classstaticblockdefinition-record-specification-type" title="The ClassStaticBlockDefinition Record Specification Type"><span class="secnum">6.2.13</span> The ClassStaticBlockDefinition Record Specification Type</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-abstract-operations" title="Abstract Operations"><span class="secnum">7</span> Abstract Operations</a><ol class="toc"><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-type-conversion" title="Type Conversion"><span class="secnum">7.1</span> Type Conversion</a><ol class="toc"><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-toprimitive" title="ToPrimitive ( input [ , preferredType ] )"><span class="secnum">7.1.1</span> ToPrimitive ( <var>input</var> [ , <var>preferredType</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-ordinarytoprimitive" title="OrdinaryToPrimitive ( O, hint )"><span class="secnum">7.1.1.1</span> OrdinaryToPrimitive ( <var>O</var>, <var>hint</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-toboolean" title="ToBoolean ( argument )"><span class="secnum">7.1.2</span> ToBoolean ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tonumeric" title="ToNumeric ( value )"><span class="secnum">7.1.3</span> ToNumeric ( <var>value</var> )</a></li><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-tonumber" title="ToNumber ( argument )"><span class="secnum">7.1.4</span> ToNumber ( <var>argument</var> )</a><ol class="toc"><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-tonumber-applied-to-the-string-type" title="ToNumber Applied to the String Type"><span class="secnum">7.1.4.1</span> ToNumber Applied to the String Type</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-stringtonumber" title="StringToNumber ( str )"><span class="secnum">7.1.4.1.1</span> StringToNumber ( <var>str</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-runtime-semantics-stringnumericvalue" title="Runtime Semantics: StringNumericValue"><span class="secnum">7.1.4.1.2</span> RS: StringNumericValue</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-roundmvresult" title="RoundMVResult ( n )"><span class="secnum">7.1.4.1.3</span> RoundMVResult ( <var>n</var> )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tointegerorinfinity" title="ToIntegerOrInfinity ( argument )"><span class="secnum">7.1.5</span> ToIntegerOrInfinity ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-toint32" title="ToInt32 ( argument )"><span class="secnum">7.1.6</span> ToInt32 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-touint32" title="ToUint32 ( argument )"><span class="secnum">7.1.7</span> ToUint32 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-toint16" title="ToInt16 ( argument )"><span class="secnum">7.1.8</span> ToInt16 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-touint16" title="ToUint16 ( argument )"><span class="secnum">7.1.9</span> ToUint16 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-toint8" title="ToInt8 ( argument )"><span class="secnum">7.1.10</span> ToInt8 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-touint8" title="ToUint8 ( argument )"><span class="secnum">7.1.11</span> ToUint8 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-touint8clamp" title="ToUint8Clamp ( argument )"><span class="secnum">7.1.12</span> ToUint8Clamp ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tobigint" title="ToBigInt ( argument )"><span class="secnum">7.1.13</span> ToBigInt ( <var>argument</var> )</a></li><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-stringtobigint" title="StringToBigInt ( str )"><span class="secnum">7.1.14</span> StringToBigInt ( <var>str</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-stringintegerliteral-grammar" title="StringIntegerLiteral Grammar"><span class="secnum">7.1.14.1</span> StringIntegerLiteral Grammar</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-runtime-semantics-mv-for-stringintegerliteral" title="Runtime Semantics: MV"><span class="secnum">7.1.14.2</span> RS: MV</a></li></ol></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tobigint64" title="ToBigInt64 ( argument )"><span class="secnum">7.1.15</span> ToBigInt64 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tobiguint64" title="ToBigUint64 ( argument )"><span class="secnum">7.1.16</span> ToBigUint64 ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tostring" title="ToString ( argument )"><span class="secnum">7.1.17</span> ToString ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-toobject" title="ToObject ( argument )"><span class="secnum">7.1.18</span> ToObject ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-topropertykey" title="ToPropertyKey ( argument )"><span class="secnum">7.1.19</span> ToPropertyKey ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-tolength" title="ToLength ( argument )"><span class="secnum">7.1.20</span> ToLength ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-canonicalnumericindexstring" title="CanonicalNumericIndexString ( argument )"><span class="secnum">7.1.21</span> CanonicalNumericIndexString ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-toindex" title="ToIndex ( value )"><span class="secnum">7.1.22</span> ToIndex ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-testing-and-comparison-operations" title="Testing and Comparison Operations"><span class="secnum">7.2</span> Testing and Comparison Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-requireobjectcoercible" title="RequireObjectCoercible ( argument )"><span class="secnum">7.2.1</span> RequireObjectCoercible ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-isarray" title="IsArray ( argument )"><span class="secnum">7.2.2</span> IsArray ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iscallable" title="IsCallable ( argument )"><span class="secnum">7.2.3</span> IsCallable ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-isconstructor" title="IsConstructor ( argument )"><span class="secnum">7.2.4</span> IsConstructor ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-isextensible-o" title="IsExtensible ( O )"><span class="secnum">7.2.5</span> IsExtensible ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-isregexp" title="IsRegExp ( argument )"><span class="secnum">7.2.6</span> IsRegExp ( <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-isstringwellformedunicode" title="Static Semantics: IsStringWellFormedUnicode ( string )"><span class="secnum">7.2.7</span> SS: IsStringWellFormedUnicode ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-sametype" title="SameType ( x, y )"><span class="secnum">7.2.8</span> SameType ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-samevalue" title="SameValue ( x, y )"><span class="secnum">7.2.9</span> SameValue ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-samevaluezero" title="SameValueZero ( x, y )"><span class="secnum">7.2.10</span> SameValueZero ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-samevaluenonnumber" title="SameValueNonNumber ( x, y )"><span class="secnum">7.2.11</span> SameValueNonNumber ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-islessthan" title="IsLessThan ( x, y, LeftFirst )"><span class="secnum">7.2.12</span> IsLessThan ( <var>x</var>, <var>y</var>, <var>LeftFirst</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-islooselyequal" title="IsLooselyEqual ( x, y )"><span class="secnum">7.2.13</span> IsLooselyEqual ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-isstrictlyequal" title="IsStrictlyEqual ( x, y )"><span class="secnum">7.2.14</span> IsStrictlyEqual ( <var>x</var>, <var>y</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-operations-on-objects" title="Operations on Objects"><span class="secnum">7.3</span> Operations on Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-makebasicobject" title="MakeBasicObject ( internalSlotsList )"><span class="secnum">7.3.1</span> MakeBasicObject ( <var>internalSlotsList</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-get-o-p" title="Get ( O, P )"><span class="secnum">7.3.2</span> Get ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getv" title="GetV ( V, P )"><span class="secnum">7.3.3</span> GetV ( <var>V</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-set-o-p-v-throw" title="Set ( O, P, V, Throw )"><span class="secnum">7.3.4</span> Set ( <var>O</var>, <var>P</var>, <var>V</var>, <var>Throw</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createdataproperty" title="CreateDataProperty ( O, P, V )"><span class="secnum">7.3.5</span> CreateDataProperty ( <var>O</var>, <var>P</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createdatapropertyorthrow" title="CreateDataPropertyOrThrow ( O, P, V )"><span class="secnum">7.3.6</span> CreateDataPropertyOrThrow ( <var>O</var>, <var>P</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createnonenumerabledatapropertyorthrow" title="CreateNonEnumerableDataPropertyOrThrow ( O, P, V )"><span class="secnum">7.3.7</span> CreateNonEnumerableDataPropertyOrThrow ( <var>O</var>, <var>P</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-definepropertyorthrow" title="DefinePropertyOrThrow ( O, P, desc )"><span class="secnum">7.3.8</span> DefinePropertyOrThrow ( <var>O</var>, <var>P</var>, <var>desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-deletepropertyorthrow" title="DeletePropertyOrThrow ( O, P )"><span class="secnum">7.3.9</span> DeletePropertyOrThrow ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getmethod" title="GetMethod ( V, P )"><span class="secnum">7.3.10</span> GetMethod ( <var>V</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-hasproperty" title="HasProperty ( O, P )"><span class="secnum">7.3.11</span> HasProperty ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-hasownproperty" title="HasOwnProperty ( O, P )"><span class="secnum">7.3.12</span> HasOwnProperty ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-call" title="Call ( F, V [ , argumentsList ] )"><span class="secnum">7.3.13</span> Call ( <var>F</var>, <var>V</var> [ , <var>argumentsList</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-construct" title="Construct ( F [ , argumentsList [ , newTarget ] ] )"><span class="secnum">7.3.14</span> Construct ( <var>F</var> [ , <var>argumentsList</var> [ , <var>newTarget</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-setintegritylevel" title="SetIntegrityLevel ( O, level )"><span class="secnum">7.3.15</span> SetIntegrityLevel ( <var>O</var>, <var>level</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-testintegritylevel" title="TestIntegrityLevel ( O, level )"><span class="secnum">7.3.16</span> TestIntegrityLevel ( <var>O</var>, <var>level</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createarrayfromlist" title="CreateArrayFromList ( elements )"><span class="secnum">7.3.17</span> CreateArrayFromList ( <var>elements</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-lengthofarraylike" title="LengthOfArrayLike ( obj )"><span class="secnum">7.3.18</span> LengthOfArrayLike ( <var>obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createlistfromarraylike" title="CreateListFromArrayLike ( obj [ , validElementTypes ] )"><span class="secnum">7.3.19</span> CreateListFromArrayLike ( <var>obj</var> [ , <var>validElementTypes</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-invoke" title="Invoke ( V, P [ , argumentsList ] )"><span class="secnum">7.3.20</span> Invoke ( <var>V</var>, <var>P</var> [ , <var>argumentsList</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-ordinaryhasinstance" title="OrdinaryHasInstance ( C, O )"><span class="secnum">7.3.21</span> OrdinaryHasInstance ( <var>C</var>, <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-speciesconstructor" title="SpeciesConstructor ( O, defaultConstructor )"><span class="secnum">7.3.22</span> SpeciesConstructor ( <var>O</var>, <var>defaultConstructor</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-enumerableownproperties" title="EnumerableOwnProperties ( O, kind )"><span class="secnum">7.3.23</span> EnumerableOwnProperties ( <var>O</var>, <var>kind</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getfunctionrealm" title="GetFunctionRealm ( obj )"><span class="secnum">7.3.24</span> GetFunctionRealm ( <var>obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-copydataproperties" title="CopyDataProperties ( target, source, excludedItems )"><span class="secnum">7.3.25</span> CopyDataProperties ( <var>target</var>, <var>source</var>, <var>excludedItems</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-privateelementfind" title="PrivateElementFind ( O, P )"><span class="secnum">7.3.26</span> PrivateElementFind ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-privatefieldadd" title="PrivateFieldAdd ( O, P, value )"><span class="secnum">7.3.27</span> PrivateFieldAdd ( <var>O</var>, <var>P</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-privatemethodoraccessoradd" title="PrivateMethodOrAccessorAdd ( O, method )"><span class="secnum">7.3.28</span> PrivateMethodOrAccessorAdd ( <var>O</var>, <var>method</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-hostensurecanaddprivateelement" title="HostEnsureCanAddPrivateElement ( O )"><span class="secnum">7.3.29</span> HostEnsureCanAddPrivateElement ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-privateget" title="PrivateGet ( O, P )"><span class="secnum">7.3.30</span> PrivateGet ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-privateset" title="PrivateSet ( O, P, value )"><span class="secnum">7.3.31</span> PrivateSet ( <var>O</var>, <var>P</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-definefield" title="DefineField ( receiver, fieldRecord )"><span class="secnum">7.3.32</span> DefineField ( <var>receiver</var>, <var>fieldRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-initializeinstanceelements" title="InitializeInstanceElements ( O, constructor )"><span class="secnum">7.3.33</span> InitializeInstanceElements ( <var>O</var>, <var>constructor</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-add-value-to-keyed-group" title="AddValueToKeyedGroup ( groups, key, value )"><span class="secnum">7.3.34</span> AddValueToKeyedGroup ( <var>groups</var>, <var>key</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-groupby" title="GroupBy ( items, callback, keyCoercion )"><span class="secnum">7.3.35</span> GroupBy ( <var>items</var>, <var>callback</var>, <var>keyCoercion</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getoptionsobject" title="GetOptionsObject ( options )"><span class="secnum">7.3.36</span> GetOptionsObject ( <var>options</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-SetterThatIgnoresPrototypeProperties" title="SetterThatIgnoresPrototypeProperties ( thisValue, home, p, v )"><span class="secnum">7.3.37</span> SetterThatIgnoresPrototypeProperties ( <var>thisValue</var>, <var>home</var>, <var>p</var>, <var>v</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="abstract-operations.html#sec-operations-on-iterator-objects" title="Operations on Iterator Objects"><span class="secnum">7.4</span> Operations on Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iterator-records" title="Iterator Records"><span class="secnum">7.4.1</span> Iterator Records</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getiteratordirect" title="GetIteratorDirect ( obj )"><span class="secnum">7.4.2</span> GetIteratorDirect ( <var>obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getiteratorfrommethod" title="GetIteratorFromMethod ( obj, method )"><span class="secnum">7.4.3</span> GetIteratorFromMethod ( <var>obj</var>, <var>method</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getiterator" title="GetIterator ( obj, kind )"><span class="secnum">7.4.4</span> GetIterator ( <var>obj</var>, <var>kind</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-getiteratorflattenable" title="GetIteratorFlattenable ( obj, primitiveHandling )"><span class="secnum">7.4.5</span> GetIteratorFlattenable ( <var>obj</var>, <var>primitiveHandling</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratornext" title="IteratorNext ( iteratorRecord [ , value ] )"><span class="secnum">7.4.6</span> IteratorNext ( <var>iteratorRecord</var> [ , <var>value</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratorcomplete" title="IteratorComplete ( iteratorResult )"><span class="secnum">7.4.7</span> IteratorComplete ( <var>iteratorResult</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratorvalue" title="IteratorValue ( iteratorResult )"><span class="secnum">7.4.8</span> IteratorValue ( <var>iteratorResult</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratorstep" title="IteratorStep ( iteratorRecord )"><span class="secnum">7.4.9</span> IteratorStep ( <var>iteratorRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratorstepvalue" title="IteratorStepValue ( iteratorRecord )"><span class="secnum">7.4.10</span> IteratorStepValue ( <var>iteratorRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratorclose" title="IteratorClose ( iteratorRecord, completion )"><span class="secnum">7.4.11</span> IteratorClose ( <var>iteratorRecord</var>, <var>completion</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratorcloseall" title="IteratorCloseAll ( iters, completion )"><span class="secnum">7.4.12</span> IteratorCloseAll ( <var>iters</var>, <var>completion</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-ifabruptcloseiterator" title="IfAbruptCloseIterator ( value, iteratorRecord )"><span class="secnum">7.4.13</span> IfAbruptCloseIterator ( <var>value</var>, <var>iteratorRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-asynciteratorclose" title="AsyncIteratorClose ( iteratorRecord, completion )"><span class="secnum">7.4.14</span> AsyncIteratorClose ( <var>iteratorRecord</var>, <var>completion</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-ifabruptcloseasynciterator" title="IfAbruptCloseAsyncIterator ( value, iteratorRecord )"><span class="secnum">7.4.15</span> IfAbruptCloseAsyncIterator ( <var>value</var>, <var>iteratorRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createiterresultobject" title="CreateIteratorResultObject ( value, done )"><span class="secnum">7.4.16</span> CreateIteratorResultObject ( <var>value</var>, <var>done</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-createlistiteratorRecord" title="CreateListIteratorRecord ( list )"><span class="secnum">7.4.17</span> CreateListIteratorRecord ( <var>list</var> )</a></li><li><span class="item-toggle-none"></span><a href="abstract-operations.html#sec-iteratortolist" title="IteratorToList ( iteratorRecord )"><span class="secnum">7.4.18</span> IteratorToList ( <var>iteratorRecord</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-syntax-directed-operations" title="Syntax-Directed Operations"><span class="secnum">8</span> Syntax-Directed Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">8.1</span> RS: Evaluation</a></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-syntax-directed-operations-scope-analysis" title="Scope Analysis"><span class="secnum">8.2</span> Scope Analysis</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-boundnames" title="Static Semantics: BoundNames"><span class="secnum">8.2.1</span> SS: BoundNames</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-declarationpart" title="Static Semantics: DeclarationPart"><span class="secnum">8.2.2</span> SS: DeclarationPart</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-isconstantdeclaration" title="Static Semantics: IsConstantDeclaration"><span class="secnum">8.2.3</span> SS: IsConstantDeclaration</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-lexicallydeclarednames" title="Static Semantics: LexicallyDeclaredNames"><span class="secnum">8.2.4</span> SS: LexicallyDeclaredNames</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-lexicallyscopeddeclarations" title="Static Semantics: LexicallyScopedDeclarations"><span class="secnum">8.2.5</span> SS: LexicallyScopedDeclarations</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-vardeclarednames" title="Static Semantics: VarDeclaredNames"><span class="secnum">8.2.6</span> SS: VarDeclaredNames</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-varscopeddeclarations" title="Static Semantics: VarScopedDeclarations"><span class="secnum">8.2.7</span> SS: VarScopedDeclarations</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-toplevellexicallydeclarednames" title="Static Semantics: TopLevelLexicallyDeclaredNames"><span class="secnum">8.2.8</span> SS: TopLevelLexicallyDeclaredNames</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-toplevellexicallyscopeddeclarations" title="Static Semantics: TopLevelLexicallyScopedDeclarations"><span class="secnum">8.2.9</span> SS: TopLevelLexicallyScopedDeclarations</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-toplevelvardeclarednames" title="Static Semantics: TopLevelVarDeclaredNames"><span class="secnum">8.2.10</span> SS: TopLevelVarDeclaredNames</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-toplevelvarscopeddeclarations" title="Static Semantics: TopLevelVarScopedDeclarations"><span class="secnum">8.2.11</span> SS: TopLevelVarScopedDeclarations</a></li></ol></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-syntax-directed-operations-labels" title="Labels"><span class="secnum">8.3</span> Labels</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-containsduplicatelabels" title="Static Semantics: ContainsDuplicateLabels"><span class="secnum">8.3.1</span> SS: ContainsDuplicateLabels</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-containsundefinedbreaktarget" title="Static Semantics: ContainsUndefinedBreakTarget"><span class="secnum">8.3.2</span> SS: ContainsUndefinedBreakTarget</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-containsundefinedcontinuetarget" title="Static Semantics: ContainsUndefinedContinueTarget"><span class="secnum">8.3.3</span> SS: ContainsUndefinedContinueTarget</a></li></ol></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-syntax-directed-operations-function-name-inference" title="Function Name Inference"><span class="secnum">8.4</span> Function Name Inference</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-hasname" title="Static Semantics: HasName"><span class="secnum">8.4.1</span> SS: HasName</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-isfunctiondefinition" title="Static Semantics: IsFunctionDefinition"><span class="secnum">8.4.2</span> SS: IsFunctionDefinition</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-isanonymousfunctiondefinition" title="Static Semantics: IsAnonymousFunctionDefinition ( expr )"><span class="secnum">8.4.3</span> SS: IsAnonymousFunctionDefinition ( <var>expr</var> )</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-isidentifierref" title="Static Semantics: IsIdentifierRef"><span class="secnum">8.4.4</span> SS: IsIdentifierRef</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-runtime-semantics-namedevaluation" title="Runtime Semantics: NamedEvaluation"><span class="secnum">8.4.5</span> RS: NamedEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-syntax-directed-operations-contains" title="Contains"><span class="secnum">8.5</span> Contains</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-contains" title="Static Semantics: Contains"><span class="secnum">8.5.1</span> SS: Contains</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-computedpropertycontains" title="Static Semantics: ComputedPropertyContains"><span class="secnum">8.5.2</span> SS: ComputedPropertyContains</a></li></ol></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-syntax-directed-operations-miscellaneous" title="Miscellaneous"><span class="secnum">8.6</span> Miscellaneous</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-runtime-semantics-instantiatefunctionobject" title="Runtime Semantics: InstantiateFunctionObject"><span class="secnum">8.6.1</span> RS: InstantiateFunctionObject</a></li><li><span class="item-toggle">+</span><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" title="Runtime Semantics: BindingInitialization"><span class="secnum">8.6.2</span> RS: BindingInitialization</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-initializeboundname" title="InitializeBoundName ( name, value, environment )"><span class="secnum">8.6.2.1</span> InitializeBoundName ( <var>name</var>, <var>value</var>, <var>environment</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-runtime-semantics-iteratorbindinginitialization" title="Runtime Semantics: IteratorBindingInitialization"><span class="secnum">8.6.3</span> RS: IteratorBindingInitialization</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-assignmenttargettype" title="Static Semantics: AssignmentTargetType"><span class="secnum">8.6.4</span> SS: AssignmentTargetType</a></li><li><span class="item-toggle-none"></span><a href="syntax-directed-operations.html#sec-static-semantics-propname" title="Static Semantics: PropName"><span class="secnum">8.6.5</span> SS: PropName</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-executable-code-and-execution-contexts" title="Executable Code and Execution Contexts"><span class="secnum">9</span> Executable Code and Execution Contexts</a><ol class="toc"><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-environment-records" title="Environment Records"><span class="secnum">9.1</span> Environment Records</a><ol class="toc"><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-the-environment-record-type-hierarchy" title="The Environment Record Type Hierarchy"><span class="secnum">9.1.1</span> The Environment Record Type Hierarchy</a><ol class="toc"><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records" title="Declarative Environment Records"><span class="secnum">9.1.1.1</span> Declarative Environment Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-hasbinding-n" title="HasBinding ( N )"><span class="secnum">9.1.1.1.1</span> HasBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-createmutablebinding-n-d" title="CreateMutableBinding ( N, D )"><span class="secnum">9.1.1.1.2</span> CreateMutableBinding ( <var>N</var>, <var>D</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-createimmutablebinding-n-s" title="CreateImmutableBinding ( N, S )"><span class="secnum">9.1.1.1.3</span> CreateImmutableBinding ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-initializebinding-n-v" title="InitializeBinding ( N, V )"><span class="secnum">9.1.1.1.4</span> InitializeBinding ( <var>N</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-setmutablebinding-n-v-s" title="SetMutableBinding ( N, V, S )"><span class="secnum">9.1.1.1.5</span> SetMutableBinding ( <var>N</var>, <var>V</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-getbindingvalue-n-s" title="GetBindingValue ( N, S )"><span class="secnum">9.1.1.1.6</span> GetBindingValue ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-deletebinding-n" title="DeleteBinding ( N )"><span class="secnum">9.1.1.1.7</span> DeleteBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-hasthisbinding" title="HasThisBinding ( )"><span class="secnum">9.1.1.1.8</span> HasThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-getthisbinding" title="GetThisBinding ( )"><span class="secnum">9.1.1.1.9</span> GetThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-hassuperbinding" title="HasSuperBinding ( )"><span class="secnum">9.1.1.1.10</span> HasSuperBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records-withbaseobject" title="WithBaseObject ( )"><span class="secnum">9.1.1.1.11</span> WithBaseObject ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records" title="Object Environment Records"><span class="secnum">9.1.1.2</span> Object Environment Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-hasbinding-n" title="HasBinding ( N )"><span class="secnum">9.1.1.2.1</span> HasBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-createmutablebinding-n-d" title="CreateMutableBinding ( N, D )"><span class="secnum">9.1.1.2.2</span> CreateMutableBinding ( <var>N</var>, <var>D</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-createimmutablebinding-n-s" title="CreateImmutableBinding ( N, S )"><span class="secnum">9.1.1.2.3</span> CreateImmutableBinding ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-initializebinding-n-v" title="InitializeBinding ( N, V )"><span class="secnum">9.1.1.2.4</span> InitializeBinding ( <var>N</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-setmutablebinding-n-v-s" title="SetMutableBinding ( N, V, S )"><span class="secnum">9.1.1.2.5</span> SetMutableBinding ( <var>N</var>, <var>V</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-getbindingvalue-n-s" title="GetBindingValue ( N, S )"><span class="secnum">9.1.1.2.6</span> GetBindingValue ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-deletebinding-n" title="DeleteBinding ( N )"><span class="secnum">9.1.1.2.7</span> DeleteBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-hasthisbinding" title="HasThisBinding ( )"><span class="secnum">9.1.1.2.8</span> HasThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-getthisbinding" title="GetThisBinding ( )"><span class="secnum">9.1.1.2.9</span> GetThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-hassuperbinding" title="HasSuperBinding ( )"><span class="secnum">9.1.1.2.10</span> HasSuperBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-object-environment-records-withbaseobject" title="WithBaseObject ( )"><span class="secnum">9.1.1.2.11</span> WithBaseObject ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-function-environment-records" title="Function Environment Records"><span class="secnum">9.1.1.3</span> Function Environment Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-bindthisvalue" title="BindThisValue ( envRec, V )"><span class="secnum">9.1.1.3.1</span> BindThisValue ( <var>envRec</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-function-environment-records-hasthisbinding" title="HasThisBinding ( )"><span class="secnum">9.1.1.3.2</span> HasThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-function-environment-records-getthisbinding" title="GetThisBinding ( )"><span class="secnum">9.1.1.3.3</span> GetThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-function-environment-records-hassuperbinding" title="HasSuperBinding ( )"><span class="secnum">9.1.1.3.4</span> HasSuperBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-getsuperbase" title="GetSuperBase ( envRec )"><span class="secnum">9.1.1.3.5</span> GetSuperBase ( <var>envRec</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records" title="Global Environment Records"><span class="secnum">9.1.1.4</span> Global Environment Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-hasbinding-n" title="HasBinding ( N )"><span class="secnum">9.1.1.4.1</span> HasBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-createmutablebinding-n-d" title="CreateMutableBinding ( N, D )"><span class="secnum">9.1.1.4.2</span> CreateMutableBinding ( <var>N</var>, <var>D</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-createimmutablebinding-n-s" title="CreateImmutableBinding ( N, S )"><span class="secnum">9.1.1.4.3</span> CreateImmutableBinding ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-initializebinding-n-v" title="InitializeBinding ( N, V )"><span class="secnum">9.1.1.4.4</span> InitializeBinding ( <var>N</var>, <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-setmutablebinding-n-v-s" title="SetMutableBinding ( N, V, S )"><span class="secnum">9.1.1.4.5</span> SetMutableBinding ( <var>N</var>, <var>V</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-getbindingvalue-n-s" title="GetBindingValue ( N, S )"><span class="secnum">9.1.1.4.6</span> GetBindingValue ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-deletebinding-n" title="DeleteBinding ( N )"><span class="secnum">9.1.1.4.7</span> DeleteBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-hasthisbinding" title="HasThisBinding ( )"><span class="secnum">9.1.1.4.8</span> HasThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-getthisbinding" title="GetThisBinding ( )"><span class="secnum">9.1.1.4.9</span> GetThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-hassuperbinding" title="HasSuperBinding ( )"><span class="secnum">9.1.1.4.10</span> HasSuperBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-global-environment-records-withbaseobject" title="WithBaseObject ( )"><span class="secnum">9.1.1.4.11</span> WithBaseObject ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-haslexicaldeclaration" title="HasLexicalDeclaration ( envRec, N )"><span class="secnum">9.1.1.4.12</span> HasLexicalDeclaration ( <var>envRec</var>, <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-hasrestrictedglobalproperty" title="HasRestrictedGlobalProperty ( envRec, N )"><span class="secnum">9.1.1.4.13</span> HasRestrictedGlobalProperty ( <var>envRec</var>, <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-candeclareglobalvar" title="CanDeclareGlobalVar ( envRec, N )"><span class="secnum">9.1.1.4.14</span> CanDeclareGlobalVar ( <var>envRec</var>, <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-candeclareglobalfunction" title="CanDeclareGlobalFunction ( envRec, N )"><span class="secnum">9.1.1.4.15</span> CanDeclareGlobalFunction ( <var>envRec</var>, <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-createglobalvarbinding" title="CreateGlobalVarBinding ( envRec, N, D )"><span class="secnum">9.1.1.4.16</span> CreateGlobalVarBinding ( <var>envRec</var>, <var>N</var>, <var>D</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-createglobalfunctionbinding" title="CreateGlobalFunctionBinding ( envRec, N, V, D )"><span class="secnum">9.1.1.4.17</span> CreateGlobalFunctionBinding ( <var>envRec</var>, <var>N</var>, <var>V</var>, <var>D</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-module-environment-records" title="Module Environment Records"><span class="secnum">9.1.1.5</span> Module Environment Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-module-environment-records-getbindingvalue-n-s" title="GetBindingValue ( N, S )"><span class="secnum">9.1.1.5.1</span> GetBindingValue ( <var>N</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-module-environment-records-deletebinding-n" title="DeleteBinding ( N )"><span class="secnum">9.1.1.5.2</span> DeleteBinding ( <var>N</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-module-environment-records-hasthisbinding" title="HasThisBinding ( )"><span class="secnum">9.1.1.5.3</span> HasThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-module-environment-records-getthisbinding" title="GetThisBinding ( )"><span class="secnum">9.1.1.5.4</span> GetThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-createimportbinding" title="CreateImportBinding ( envRec, N, M, N2 )"><span class="secnum">9.1.1.5.5</span> CreateImportBinding ( <var>envRec</var>, <var>N</var>, <var>M</var>, <var>N2</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-environment-record-operations" title="Environment Record Operations"><span class="secnum">9.1.2</span> Environment Record Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-getidentifierreference" title="GetIdentifierReference ( env, name, strict )"><span class="secnum">9.1.2.1</span> GetIdentifierReference ( <var>env</var>, <var>name</var>, <var>strict</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment" title="NewDeclarativeEnvironment ( E )"><span class="secnum">9.1.2.2</span> NewDeclarativeEnvironment ( <var>E</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-newobjectenvironment" title="NewObjectEnvironment ( O, W, E )"><span class="secnum">9.1.2.3</span> NewObjectEnvironment ( <var>O</var>, <var>W</var>, <var>E</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-newfunctionenvironment" title="NewFunctionEnvironment ( F, newTarget )"><span class="secnum">9.1.2.4</span> NewFunctionEnvironment ( <var>F</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-newglobalenvironment" title="NewGlobalEnvironment ( G, thisValue )"><span class="secnum">9.1.2.5</span> NewGlobalEnvironment ( <var>G</var>, <var>thisValue</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-newmoduleenvironment" title="NewModuleEnvironment ( E )"><span class="secnum">9.1.2.6</span> NewModuleEnvironment ( <var>E</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-privateenvironment-records" title="PrivateEnvironment Records"><span class="secnum">9.2</span> PrivateEnvironment Records</a><ol class="toc"><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-privateenvironment-record-operations" title="PrivateEnvironment Record Operations"><span class="secnum">9.2.1</span> PrivateEnvironment Record Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-newprivateenvironment" title="NewPrivateEnvironment ( outerPrivateEnv )"><span class="secnum">9.2.1.1</span> NewPrivateEnvironment ( <var>outerPrivateEnv</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-resolve-private-identifier" title="ResolvePrivateIdentifier ( privateEnv, identifier )"><span class="secnum">9.2.1.2</span> ResolvePrivateIdentifier ( <var>privateEnv</var>, <var>identifier</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-code-realms" title="Realms"><span class="secnum">9.3</span> Realms</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-initializehostdefinedrealm" title="InitializeHostDefinedRealm ( )"><span class="secnum">9.3.1</span> InitializeHostDefinedRealm ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-createintrinsics" title="CreateIntrinsics ( realmRec )"><span class="secnum">9.3.2</span> CreateIntrinsics ( <var>realmRec</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-setdefaultglobalbindings" title="SetDefaultGlobalBindings ( realmRec )"><span class="secnum">9.3.3</span> SetDefaultGlobalBindings ( <var>realmRec</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-execution-contexts" title="Execution Contexts"><span class="secnum">9.4</span> Execution Contexts</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-getactivescriptormodule" title="GetActiveScriptOrModule ( )"><span class="secnum">9.4.1</span> GetActiveScriptOrModule ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-resolvebinding" title="ResolveBinding ( name [ , env ] )"><span class="secnum">9.4.2</span> ResolveBinding ( <var>name</var> [ , <var>env</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-getthisenvironment" title="GetThisEnvironment ( )"><span class="secnum">9.4.3</span> GetThisEnvironment ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-resolvethisbinding" title="ResolveThisBinding ( )"><span class="secnum">9.4.4</span> ResolveThisBinding ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-getnewtarget" title="GetNewTarget ( )"><span class="secnum">9.4.5</span> GetNewTarget ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-getglobalobject" title="GetGlobalObject ( )"><span class="secnum">9.4.6</span> GetGlobalObject ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-jobs" title="Jobs and Host Operations to Enqueue Jobs"><span class="secnum">9.5</span> Jobs and Host Operations to Enqueue Jobs</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-jobcallback-records" title="JobCallback Records"><span class="secnum">9.5.1</span> JobCallback Records</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-hostmakejobcallback" title="HostMakeJobCallback ( callback )"><span class="secnum">9.5.2</span> HostMakeJobCallback ( <var>callback</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-hostcalljobcallback" title="HostCallJobCallback ( jobCallback, V, argumentsList )"><span class="secnum">9.5.3</span> HostCallJobCallback ( <var>jobCallback</var>, <var>V</var>, <var>argumentsList</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-hostenqueuegenericjob" title="HostEnqueueGenericJob ( job, realm )"><span class="secnum">9.5.4</span> HostEnqueueGenericJob ( <var>job</var>, <var>realm</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-hostenqueuepromisejob" title="HostEnqueuePromiseJob ( job, realm )"><span class="secnum">9.5.5</span> HostEnqueuePromiseJob ( <var>job</var>, <var>realm</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-hostenqueuetimeoutjob" title="HostEnqueueTimeoutJob ( timeoutJob, realm, milliseconds )"><span class="secnum">9.5.6</span> HostEnqueueTimeoutJob ( <var>timeoutJob</var>, <var>realm</var>, <var>milliseconds</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-agents" title="Agents"><span class="secnum">9.6</span> Agents</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-agentsignifier" title="AgentSignifier ( )"><span class="secnum">9.6.1</span> AgentSignifier ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-agentcansuspend" title="AgentCanSuspend ( )"><span class="secnum">9.6.2</span> AgentCanSuspend ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-IncrementModuleAsyncEvaluationCount" title="IncrementModuleAsyncEvaluationCount ( )"><span class="secnum">9.6.3</span> IncrementModuleAsyncEvaluationCount ( )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-agent-clusters" title="Agent Clusters"><span class="secnum">9.7</span> Agent Clusters</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-forward-progress" title="Forward Progress"><span class="secnum">9.8</span> Forward Progress</a></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-weakref-processing-model" title="Processing Model of WeakRef and FinalizationRegistry Targets"><span class="secnum">9.9</span> Processing Model of WeakRef and FinalizationRegistry Targets</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-weakref-invariants" title="Objectives"><span class="secnum">9.9.1</span> Objectives</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-liveness" title="Liveness"><span class="secnum">9.9.2</span> Liveness</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-weakref-execution" title="Execution"><span class="secnum">9.9.3</span> Execution</a></li><li><span class="item-toggle">+</span><a href="executable-code-and-execution-contexts.html#sec-weakref-host-hooks" title="Host Hooks"><span class="secnum">9.9.4</span> Host Hooks</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-host-cleanup-finalization-registry" title="HostEnqueueFinalizationRegistryCleanupJob ( finalizationRegistry )"><span class="secnum">9.9.4.1</span> HostEnqueueFinalizationRegistryCleanupJob ( <var>finalizationRegistry</var> )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-clear-kept-objects" title="ClearKeptObjects ( )"><span class="secnum">9.10</span> ClearKeptObjects ( )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-addtokeptobjects" title="AddToKeptObjects ( value )"><span class="secnum">9.11</span> AddToKeptObjects ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-cleanup-finalization-registry" title="CleanupFinalizationRegistry ( finalizationRegistry )"><span class="secnum">9.12</span> CleanupFinalizationRegistry ( <var>finalizationRegistry</var> )</a></li><li><span class="item-toggle-none"></span><a href="executable-code-and-execution-contexts.html#sec-canbeheldweakly" title="CanBeHeldWeakly ( v )"><span class="secnum">9.13</span> CanBeHeldWeakly ( <var>v</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-and-exotic-objects-behaviours" title="Ordinary and Exotic Objects Behaviours"><span class="secnum">10</span> Ordinary and Exotic Objects Behaviours</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots" title="Ordinary Object Internal Methods and Internal Slots"><span class="secnum">10.1</span> Ordinary Object Internal Methods and Internal Slots</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-getprototypeof" title="[[GetPrototypeOf]] ( )"><span class="secnum">10.1.1</span> <var class="field">[[GetPrototypeOf]]</var> ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarygetprototypeof" title="OrdinaryGetPrototypeOf ( O )"><span class="secnum">10.1.1.1</span> OrdinaryGetPrototypeOf ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-setprototypeof-v" title="[[SetPrototypeOf]] ( V )"><span class="secnum">10.1.2</span> <var class="field">[[SetPrototypeOf]]</var> ( <var>V</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarysetprototypeof" title="OrdinarySetPrototypeOf ( O, V )"><span class="secnum">10.1.2.1</span> OrdinarySetPrototypeOf ( <var>O</var>, <var>V</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-isextensible" title="[[IsExtensible]] ( )"><span class="secnum">10.1.3</span> <var class="field">[[IsExtensible]]</var> ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryisextensible" title="OrdinaryIsExtensible ( O )"><span class="secnum">10.1.3.1</span> OrdinaryIsExtensible ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-preventextensions" title="[[PreventExtensions]] ( )"><span class="secnum">10.1.4</span> <var class="field">[[PreventExtensions]]</var> ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarypreventextensions" title="OrdinaryPreventExtensions ( O )"><span class="secnum">10.1.4.1</span> OrdinaryPreventExtensions ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-getownproperty-p" title="[[GetOwnProperty]] ( P )"><span class="secnum">10.1.5</span> <var class="field">[[GetOwnProperty]]</var> ( <var>P</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarygetownproperty" title="OrdinaryGetOwnProperty ( O, P )"><span class="secnum">10.1.5.1</span> OrdinaryGetOwnProperty ( <var>O</var>, <var>P</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-defineownproperty-p-desc" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.1.6</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarydefineownproperty" title="OrdinaryDefineOwnProperty ( O, P, Desc )"><span class="secnum">10.1.6.1</span> OrdinaryDefineOwnProperty ( <var>O</var>, <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-iscompatiblepropertydescriptor" title="IsCompatiblePropertyDescriptor ( Extensible, Desc, Current )"><span class="secnum">10.1.6.2</span> IsCompatiblePropertyDescriptor ( <var>Extensible</var>, <var>Desc</var>, <var>Current</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-validateandapplypropertydescriptor" title="ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current )"><span class="secnum">10.1.6.3</span> ValidateAndApplyPropertyDescriptor ( <var>O</var>, <var>P</var>, <var>extensible</var>, <var>Desc</var>, <var>current</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-hasproperty-p" title="[[HasProperty]] ( P )"><span class="secnum">10.1.7</span> <var class="field">[[HasProperty]]</var> ( <var>P</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryhasproperty" title="OrdinaryHasProperty ( O, P )"><span class="secnum">10.1.7.1</span> OrdinaryHasProperty ( <var>O</var>, <var>P</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-get-p-receiver" title="[[Get]] ( P, Receiver )"><span class="secnum">10.1.8</span> <var class="field">[[Get]]</var> ( <var>P</var>, <var>Receiver</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryget" title="OrdinaryGet ( O, P, Receiver )"><span class="secnum">10.1.8.1</span> OrdinaryGet ( <var>O</var>, <var>P</var>, <var>Receiver</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-set-p-v-receiver" title="[[Set]] ( P, V, Receiver )"><span class="secnum">10.1.9</span> <var class="field">[[Set]]</var> ( <var>P</var>, <var>V</var>, <var>Receiver</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryset" title="OrdinarySet ( O, P, V, Receiver )"><span class="secnum">10.1.9.1</span> OrdinarySet ( <var>O</var>, <var>P</var>, <var>V</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarysetwithowndescriptor" title="OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )"><span class="secnum">10.1.9.2</span> OrdinarySetWithOwnDescriptor ( <var>O</var>, <var>P</var>, <var>V</var>, <var>Receiver</var>, <var>ownDesc</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-delete-p" title="[[Delete]] ( P )"><span class="secnum">10.1.10</span> <var class="field">[[Delete]]</var> ( <var>P</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarydelete" title="OrdinaryDelete ( O, P )"><span class="secnum">10.1.10.1</span> OrdinaryDelete ( <var>O</var>, <var>P</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinary-object-internal-methods-and-internal-slots-ownpropertykeys" title="[[OwnPropertyKeys]] ( )"><span class="secnum">10.1.11</span> <var class="field">[[OwnPropertyKeys]]</var> ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryownpropertykeys" title="OrdinaryOwnPropertyKeys ( O )"><span class="secnum">10.1.11.1</span> OrdinaryOwnPropertyKeys ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate" title="OrdinaryObjectCreate ( proto [ , additionalInternalSlotsList ] )"><span class="secnum">10.1.12</span> OrdinaryObjectCreate ( <var>proto</var> [ , <var>additionalInternalSlotsList</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarycreatefromconstructor" title="OrdinaryCreateFromConstructor ( constructor, intrinsicDefaultProto [ , internalSlotsList ] )"><span class="secnum">10.1.13</span> OrdinaryCreateFromConstructor ( <var>constructor</var>, <var>intrinsicDefaultProto</var> [ , <var>internalSlotsList</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-getprototypefromconstructor" title="GetPrototypeFromConstructor ( constructor, intrinsicDefaultProto )"><span class="secnum">10.1.14</span> GetPrototypeFromConstructor ( <var>constructor</var>, <var>intrinsicDefaultProto</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot" title="RequireInternalSlot ( O, internalSlot )"><span class="secnum">10.1.15</span> RequireInternalSlot ( <var>O</var>, <var>internalSlot</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ecmascript-function-objects" title="ECMAScript Function Objects"><span class="secnum">10.2</span> ECMAScript Function Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ecmascript-function-objects-call-thisargument-argumentslist" title="[[Call]] ( thisArgument, argumentsList )"><span class="secnum">10.2.1</span> <var class="field">[[Call]]</var> ( <var>thisArgument</var>, <var>argumentsList</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-prepareforordinarycall" title="PrepareForOrdinaryCall ( F, newTarget )"><span class="secnum">10.2.1.1</span> PrepareForOrdinaryCall ( <var>F</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarycallbindthis" title="OrdinaryCallBindThis ( F, calleeContext, thisArgument )"><span class="secnum">10.2.1.2</span> OrdinaryCallBindThis ( <var>F</var>, <var>calleeContext</var>, <var>thisArgument</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-runtime-semantics-evaluatebody" title="Runtime Semantics: EvaluateBody"><span class="secnum">10.2.1.3</span> RS: EvaluateBody</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarycallevaluatebody" title="OrdinaryCallEvaluateBody ( F, argumentsList )"><span class="secnum">10.2.1.4</span> OrdinaryCallEvaluateBody ( <var>F</var>, <var>argumentsList</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ecmascript-function-objects-construct-argumentslist-newtarget" title="[[Construct]] ( argumentsList, newTarget )"><span class="secnum">10.2.2</span> <var class="field">[[Construct]]</var> ( <var>argumentsList</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryfunctioncreate" title="OrdinaryFunctionCreate ( functionPrototype, sourceText, ParameterList, Body, thisMode, env, privateEnv )"><span class="secnum">10.2.3</span> OrdinaryFunctionCreate ( <var>functionPrototype</var>, <var>sourceText</var>, <var>ParameterList</var>, <var>Body</var>, <var>thisMode</var>, <var>env</var>, <var>privateEnv</var> )</a></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-addrestrictedfunctionproperties" title="AddRestrictedFunctionProperties ( F, realm )"><span class="secnum">10.2.4</span> AddRestrictedFunctionProperties ( <var>F</var>, <var>realm</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-%throwtypeerror%" title="%ThrowTypeError% ( )"><span class="secnum">10.2.4.1</span> %ThrowTypeError% ( )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-makeconstructor" title="MakeConstructor ( F [ , writablePrototype [ , prototype ] ] )"><span class="secnum">10.2.5</span> MakeConstructor ( <var>F</var> [ , <var>writablePrototype</var> [ , <var>prototype</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-makeclassconstructor" title="MakeClassConstructor ( F )"><span class="secnum">10.2.6</span> MakeClassConstructor ( <var>F</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-makemethod" title="MakeMethod ( F, homeObject )"><span class="secnum">10.2.7</span> MakeMethod ( <var>F</var>, <var>homeObject</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-definemethodproperty" title="DefineMethodProperty ( homeObject, key, closure, enumerable )"><span class="secnum">10.2.8</span> DefineMethodProperty ( <var>homeObject</var>, <var>key</var>, <var>closure</var>, <var>enumerable</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-setfunctionname" title="SetFunctionName ( F, name [ , prefix ] )"><span class="secnum">10.2.9</span> SetFunctionName ( <var>F</var>, <var>name</var> [ , <var>prefix</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-setfunctionlength" title="SetFunctionLength ( F, length )"><span class="secnum">10.2.10</span> SetFunctionLength ( <var>F</var>, <var>length</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-functiondeclarationinstantiation" title="FunctionDeclarationInstantiation ( func, argumentsList )"><span class="secnum">10.2.11</span> FunctionDeclarationInstantiation ( <var>func</var>, <var>argumentsList</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-built-in-function-objects" title="Built-in Function Objects"><span class="secnum">10.3</span> Built-in Function Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-built-in-function-objects-call-thisargument-argumentslist" title="[[Call]] ( thisArgument, argumentsList )"><span class="secnum">10.3.1</span> <var class="field">[[Call]]</var> ( <var>thisArgument</var>, <var>argumentsList</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-built-in-function-objects-construct-argumentslist-newtarget" title="[[Construct]] ( argumentsList, newTarget )"><span class="secnum">10.3.2</span> <var class="field">[[Construct]]</var> ( <var>argumentsList</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-builtincallorconstruct" title="BuiltinCallOrConstruct ( F, thisArgument, argumentsList, newTarget )"><span class="secnum">10.3.3</span> BuiltinCallOrConstruct ( <var>F</var>, <var>thisArgument</var>, <var>argumentsList</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction" title="CreateBuiltinFunction ( behaviour, length, name, additionalInternalSlotsList [ , realm [ , prototype [ , prefix [ , async ] ] ] ] )"><span class="secnum">10.3.4</span> CreateBuiltinFunction ( <var>behaviour</var>, <var>length</var>, <var>name</var>, <var>additionalInternalSlotsList</var> [ , <var>realm</var> [ , <var>prototype</var> [ , <var>prefix</var> [ , <var>async</var> ] ] ] ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-built-in-exotic-object-internal-methods-and-slots" title="Built-in Exotic Object Internal Methods and Slots"><span class="secnum">10.4</span> Built-in Exotic Object Internal Methods and Slots</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-bound-function-exotic-objects" title="Bound Function Exotic Objects"><span class="secnum">10.4.1</span> Bound Function Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-bound-function-exotic-objects-call-thisargument-argumentslist" title="[[Call]] ( thisArgument, argumentsList )"><span class="secnum">10.4.1.1</span> <var class="field">[[Call]]</var> ( <var>thisArgument</var>, <var>argumentsList</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-bound-function-exotic-objects-construct-argumentslist-newtarget" title="[[Construct]] ( argumentsList, newTarget )"><span class="secnum">10.4.1.2</span> <var class="field">[[Construct]]</var> ( <var>argumentsList</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-boundfunctioncreate" title="BoundFunctionCreate ( targetFunction, boundThis, boundArgs )"><span class="secnum">10.4.1.3</span> BoundFunctionCreate ( <var>targetFunction</var>, <var>boundThis</var>, <var>boundArgs</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-array-exotic-objects" title="Array Exotic Objects"><span class="secnum">10.4.2</span> Array Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-array-exotic-objects-defineownproperty-p-desc" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.4.2.1</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arraycreate" title="ArrayCreate ( length [ , proto ] )"><span class="secnum">10.4.2.2</span> ArrayCreate ( <var>length</var> [ , <var>proto</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arrayspeciescreate" title="ArraySpeciesCreate ( originalArray, length )"><span class="secnum">10.4.2.3</span> ArraySpeciesCreate ( <var>originalArray</var>, <var>length</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arraysetlength" title="ArraySetLength ( A, Desc )"><span class="secnum">10.4.2.4</span> ArraySetLength ( <var>A</var>, <var>Desc</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-string-exotic-objects" title="String Exotic Objects"><span class="secnum">10.4.3</span> String Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-string-exotic-objects-getownproperty-p" title="[[GetOwnProperty]] ( P )"><span class="secnum">10.4.3.1</span> <var class="field">[[GetOwnProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-string-exotic-objects-defineownproperty-p-desc" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.4.3.2</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-string-exotic-objects-ownpropertykeys" title="[[OwnPropertyKeys]] ( )"><span class="secnum">10.4.3.3</span> <var class="field">[[OwnPropertyKeys]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-stringcreate" title="StringCreate ( value, prototype )"><span class="secnum">10.4.3.4</span> StringCreate ( <var>value</var>, <var>prototype</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-stringgetownproperty" title="StringGetOwnProperty ( S, P )"><span class="secnum">10.4.3.5</span> StringGetOwnProperty ( <var>S</var>, <var>P</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arguments-exotic-objects" title="Arguments Exotic Objects"><span class="secnum">10.4.4</span> Arguments Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arguments-exotic-objects-getownproperty-p" title="[[GetOwnProperty]] ( P )"><span class="secnum">10.4.4.1</span> <var class="field">[[GetOwnProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arguments-exotic-objects-defineownproperty-p-desc" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.4.4.2</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arguments-exotic-objects-get-p-receiver" title="[[Get]] ( P, Receiver )"><span class="secnum">10.4.4.3</span> <var class="field">[[Get]]</var> ( <var>P</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arguments-exotic-objects-set-p-v-receiver" title="[[Set]] ( P, V, Receiver )"><span class="secnum">10.4.4.4</span> <var class="field">[[Set]]</var> ( <var>P</var>, <var>V</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-arguments-exotic-objects-delete-p" title="[[Delete]] ( P )"><span class="secnum">10.4.4.5</span> <var class="field">[[Delete]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-createunmappedargumentsobject" title="CreateUnmappedArgumentsObject ( argumentsList )"><span class="secnum">10.4.4.6</span> CreateUnmappedArgumentsObject ( <var>argumentsList</var> )</a></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-createmappedargumentsobject" title="CreateMappedArgumentsObject ( func, formals, argumentsList, env )"><span class="secnum">10.4.4.7</span> CreateMappedArgumentsObject ( <var>func</var>, <var>formals</var>, <var>argumentsList</var>, <var>env</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-makearggetter" title="MakeArgGetter ( name, env )"><span class="secnum">10.4.4.7.1</span> MakeArgGetter ( <var>name</var>, <var>env</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-makeargsetter" title="MakeArgSetter ( name, env )"><span class="secnum">10.4.4.7.2</span> MakeArgSetter ( <var>name</var>, <var>env</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-exotic-objects" title="TypedArray Exotic Objects"><span class="secnum">10.4.5</span> TypedArray Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-preventextensions" title="[[PreventExtensions]] ( )"><span class="secnum">10.4.5.1</span> <var class="field">[[PreventExtensions]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-getownproperty" title="[[GetOwnProperty]] ( P )"><span class="secnum">10.4.5.2</span> <var class="field">[[GetOwnProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-hasproperty" title="[[HasProperty]] ( P )"><span class="secnum">10.4.5.3</span> <var class="field">[[HasProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-defineownproperty" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.4.5.4</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-get" title="[[Get]] ( P, Receiver )"><span class="secnum">10.4.5.5</span> <var class="field">[[Get]]</var> ( <var>P</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-set" title="[[Set]] ( P, V, Receiver )"><span class="secnum">10.4.5.6</span> <var class="field">[[Set]]</var> ( <var>P</var>, <var>V</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-delete" title="[[Delete]] ( P )"><span class="secnum">10.4.5.7</span> <var class="field">[[Delete]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-ownpropertykeys" title="[[OwnPropertyKeys]] ( )"><span class="secnum">10.4.5.8</span> <var class="field">[[OwnPropertyKeys]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarray-with-buffer-witness-records" title="TypedArray With Buffer Witness Records"><span class="secnum">10.4.5.9</span> TypedArray With Buffer Witness Records</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-maketypedarraywithbufferwitnessrecord" title="MakeTypedArrayWithBufferWitnessRecord ( obj, order )"><span class="secnum">10.4.5.10</span> MakeTypedArrayWithBufferWitnessRecord ( <var>obj</var>, <var>order</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarraycreate" title="TypedArrayCreate ( prototype )"><span class="secnum">10.4.5.11</span> TypedArrayCreate ( <var>prototype</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarraybytelength" title="TypedArrayByteLength ( taRecord )"><span class="secnum">10.4.5.12</span> TypedArrayByteLength ( <var>taRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarraylength" title="TypedArrayLength ( taRecord )"><span class="secnum">10.4.5.13</span> TypedArrayLength ( <var>taRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-istypedarrayoutofbounds" title="IsTypedArrayOutOfBounds ( taRecord )"><span class="secnum">10.4.5.14</span> IsTypedArrayOutOfBounds ( <var>taRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-istypedarrayfixedlength" title="IsTypedArrayFixedLength ( O )"><span class="secnum">10.4.5.15</span> IsTypedArrayFixedLength ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-isvalidintegerindex" title="IsValidIntegerIndex ( O, index )"><span class="secnum">10.4.5.16</span> IsValidIntegerIndex ( <var>O</var>, <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarraygetelement" title="TypedArrayGetElement ( O, index )"><span class="secnum">10.4.5.17</span> TypedArrayGetElement ( <var>O</var>, <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-typedarraysetelement" title="TypedArraySetElement ( O, index, value )"><span class="secnum">10.4.5.18</span> TypedArraySetElement ( <var>O</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-isarraybufferviewoutofbounds" title="IsArrayBufferViewOutOfBounds ( O )"><span class="secnum">10.4.5.19</span> IsArrayBufferViewOutOfBounds ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects" title="Module Namespace Exotic Objects"><span class="secnum">10.4.6</span> Module Namespace Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-getprototypeof" title="[[GetPrototypeOf]] ( )"><span class="secnum">10.4.6.1</span> <var class="field">[[GetPrototypeOf]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-setprototypeof-v" title="[[SetPrototypeOf]] ( V )"><span class="secnum">10.4.6.2</span> <var class="field">[[SetPrototypeOf]]</var> ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-isextensible" title="[[IsExtensible]] ( )"><span class="secnum">10.4.6.3</span> <var class="field">[[IsExtensible]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-preventextensions" title="[[PreventExtensions]] ( )"><span class="secnum">10.4.6.4</span> <var class="field">[[PreventExtensions]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-getownproperty-p" title="[[GetOwnProperty]] ( P )"><span class="secnum">10.4.6.5</span> <var class="field">[[GetOwnProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-defineownproperty-p-desc" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.4.6.6</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-hasproperty-p" title="[[HasProperty]] ( P )"><span class="secnum">10.4.6.7</span> <var class="field">[[HasProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-get-p-receiver" title="[[Get]] ( P, Receiver )"><span class="secnum">10.4.6.8</span> <var class="field">[[Get]]</var> ( <var>P</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-set-p-v-receiver" title="[[Set]] ( P, V, Receiver )"><span class="secnum">10.4.6.9</span> <var class="field">[[Set]]</var> ( <var>P</var>, <var>V</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-delete-p" title="[[Delete]] ( P )"><span class="secnum">10.4.6.10</span> <var class="field">[[Delete]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-module-namespace-exotic-objects-ownpropertykeys" title="[[OwnPropertyKeys]] ( )"><span class="secnum">10.4.6.11</span> <var class="field">[[OwnPropertyKeys]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-modulenamespacecreate" title="ModuleNamespaceCreate ( module, exports )"><span class="secnum">10.4.6.12</span> ModuleNamespaceCreate ( <var>module</var>, <var>exports</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-immutable-prototype-exotic-objects" title="Immutable Prototype Exotic Objects"><span class="secnum">10.4.7</span> Immutable Prototype Exotic Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-immutable-prototype-exotic-objects-setprototypeof-v" title="[[SetPrototypeOf]] ( V )"><span class="secnum">10.4.7.1</span> <var class="field">[[SetPrototypeOf]]</var> ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-set-immutable-prototype" title="SetImmutablePrototype ( O, V )"><span class="secnum">10.4.7.2</span> SetImmutablePrototype ( <var>O</var>, <var>V</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots" title="Proxy Object Internal Methods and Internal Slots"><span class="secnum">10.5</span> Proxy Object Internal Methods and Internal Slots</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-getprototypeof" title="[[GetPrototypeOf]] ( )"><span class="secnum">10.5.1</span> <var class="field">[[GetPrototypeOf]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-setprototypeof-v" title="[[SetPrototypeOf]] ( V )"><span class="secnum">10.5.2</span> <var class="field">[[SetPrototypeOf]]</var> ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-isextensible" title="[[IsExtensible]] ( )"><span class="secnum">10.5.3</span> <var class="field">[[IsExtensible]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-preventextensions" title="[[PreventExtensions]] ( )"><span class="secnum">10.5.4</span> <var class="field">[[PreventExtensions]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-getownproperty-p" title="[[GetOwnProperty]] ( P )"><span class="secnum">10.5.5</span> <var class="field">[[GetOwnProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc" title="[[DefineOwnProperty]] ( P, Desc )"><span class="secnum">10.5.6</span> <var class="field">[[DefineOwnProperty]]</var> ( <var>P</var>, <var>Desc</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-hasproperty-p" title="[[HasProperty]] ( P )"><span class="secnum">10.5.7</span> <var class="field">[[HasProperty]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-get-p-receiver" title="[[Get]] ( P, Receiver )"><span class="secnum">10.5.8</span> <var class="field">[[Get]]</var> ( <var>P</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-set-p-v-receiver" title="[[Set]] ( P, V, Receiver )"><span class="secnum">10.5.9</span> <var class="field">[[Set]]</var> ( <var>P</var>, <var>V</var>, <var>Receiver</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-delete-p" title="[[Delete]] ( P )"><span class="secnum">10.5.10</span> <var class="field">[[Delete]]</var> ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-ownpropertykeys" title="[[OwnPropertyKeys]] ( )"><span class="secnum">10.5.11</span> <var class="field">[[OwnPropertyKeys]]</var> ( )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-call-thisargument-argumentslist" title="[[Call]] ( thisArgument, argumentsList )"><span class="secnum">10.5.12</span> <var class="field">[[Call]]</var> ( <var>thisArgument</var>, <var>argumentsList</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxy-object-internal-methods-and-internal-slots-construct-argumentslist-newtarget" title="[[Construct]] ( argumentsList, newTarget )"><span class="secnum">10.5.13</span> <var class="field">[[Construct]]</var> ( <var>argumentsList</var>, <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-validatenonrevokedproxy" title="ValidateNonRevokedProxy ( proxy )"><span class="secnum">10.5.14</span> ValidateNonRevokedProxy ( <var>proxy</var> )</a></li><li><span class="item-toggle-none"></span><a href="ordinary-and-exotic-objects-behaviours.html#sec-proxycreate" title="ProxyCreate ( target, handler )"><span class="secnum">10.5.15</span> ProxyCreate ( <var>target</var>, <var>handler</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-source-code.html#sec-ecmascript-language-source-code" title="ECMAScript Language: Source Text"><span class="secnum">11</span> ECMAScript Language: Source Text</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-source-code.html#sec-source-text" title="Source Text"><span class="secnum">11.1</span> Source Text</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-utf16encodecodepoint" title="Static Semantics: UTF16EncodeCodePoint ( cp )"><span class="secnum">11.1.1</span> SS: UTF16EncodeCodePoint ( <var>cp</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-codepointstostring" title="Static Semantics: CodePointsToString ( text )"><span class="secnum">11.1.2</span> SS: CodePointsToString ( <var>text</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-utf16decodesurrogatepair" title="Static Semantics: UTF16SurrogatePairToCodePoint ( lead, trail )"><span class="secnum">11.1.3</span> SS: UTF16SurrogatePairToCodePoint ( <var>lead</var>, <var>trail</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-codepointat" title="Static Semantics: CodePointAt ( string, position )"><span class="secnum">11.1.4</span> SS: CodePointAt ( <var>string</var>, <var>position</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-stringtocodepoints" title="Static Semantics: StringToCodePoints ( string )"><span class="secnum">11.1.5</span> SS: StringToCodePoints ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-parsetext" title="Static Semantics: ParseText ( sourceText, goalSymbol )"><span class="secnum">11.1.6</span> SS: ParseText ( <var>sourceText</var>, <var>goalSymbol</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-source-code.html#sec-types-of-source-code" title="Types of Source Code"><span class="secnum">11.2</span> Types of Source Code</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-directive-prologues-and-the-use-strict-directive" title="Directive Prologues and the Use Strict Directive"><span class="secnum">11.2.1</span> Directive Prologues and the Use Strict Directive</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-source-code.html#sec-strict-mode-code" title="Strict Mode Code"><span class="secnum">11.2.2</span> Strict Mode Code</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-isstrict" title="Static Semantics: IsStrict ( node )"><span class="secnum">11.2.2.1</span> SS: IsStrict ( <var>node</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-source-code.html#sec-non-ecmascript-functions" title="Non-ECMAScript Functions"><span class="secnum">11.2.3</span> Non-ECMAScript Functions</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-ecmascript-language-lexical-grammar" title="ECMAScript Language: Lexical Grammar"><span class="secnum">12</span> ECMAScript Language: Lexical Grammar</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-unicode-format-control-characters" title="Unicode Format-Control Characters"><span class="secnum">12.1</span> Unicode Format-Control Characters</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-white-space" title="White Space"><span class="secnum">12.2</span> White Space</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-line-terminators" title="Line Terminators"><span class="secnum">12.3</span> Line Terminators</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-comments" title="Comments"><span class="secnum">12.4</span> Comments</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-hashbang" title="Hashbang Comments"><span class="secnum">12.5</span> Hashbang Comments</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-tokens" title="Tokens"><span class="secnum">12.6</span> Tokens</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-names-and-keywords" title="Names and Keywords"><span class="secnum">12.7</span> Names and Keywords</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-identifier-names" title="Identifier Names"><span class="secnum">12.7.1</span> Identifier Names</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-identifier-names-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">12.7.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-identifiercodepoints" title="Static Semantics: IdentifierCodePoints"><span class="secnum">12.7.1.2</span> SS: IdentifierCodePoints</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-identifiercodepoint" title="Static Semantics: IdentifierCodePoint"><span class="secnum">12.7.1.3</span> SS: IdentifierCodePoint</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-keywords-and-reserved-words" title="Keywords and Reserved Words"><span class="secnum">12.7.2</span> Keywords and Reserved Words</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-punctuators" title="Punctuators"><span class="secnum">12.8</span> Punctuators</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-ecmascript-language-lexical-grammar-literals" title="Literals"><span class="secnum">12.9</span> Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-null-literals" title="Null Literals"><span class="secnum">12.9.1</span> Null Literals</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-boolean-literals" title="Boolean Literals"><span class="secnum">12.9.2</span> Boolean Literals</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-literals-numeric-literals" title="Numeric Literals"><span class="secnum">12.9.3</span> Numeric Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-numeric-literals-early-errors" title="Static Semantics: Early Errors"><span class="secnum">12.9.3.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-static-semantics-mv" title="Static Semantics: MV"><span class="secnum">12.9.3.2</span> SS: MV</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-numericvalue" title="Static Semantics: NumericValue"><span class="secnum">12.9.3.3</span> SS: NumericValue</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-literals-string-literals" title="String Literals"><span class="secnum">12.9.4</span> String Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-string-literals-early-errors" title="Static Semantics: Early Errors"><span class="secnum">12.9.4.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-static-semantics-sv" title="Static Semantics: SV"><span class="secnum">12.9.4.2</span> SS: SV</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-string-literals-static-semantics-mv" title="Static Semantics: MV"><span class="secnum">12.9.4.3</span> SS: MV</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-literals-regular-expression-literals" title="Regular Expression Literals"><span class="secnum">12.9.5</span> Regular Expression Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-static-semantics-bodytext" title="Static Semantics: BodyText"><span class="secnum">12.9.5.1</span> SS: BodyText</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-static-semantics-flagtext" title="Static Semantics: FlagText"><span class="secnum">12.9.5.2</span> SS: FlagText</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-template-literal-lexical-components" title="Template Literal Lexical Components"><span class="secnum">12.9.6</span> Template Literal Lexical Components</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-static-semantics-tv" title="Static Semantics: TV"><span class="secnum">12.9.6.1</span> SS: TV</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-static-semantics-trv" title="Static Semantics: TRV"><span class="secnum">12.9.6.2</span> SS: TRV</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-automatic-semicolon-insertion" title="Automatic Semicolon Insertion"><span class="secnum">12.10</span> Automatic Semicolon Insertion</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-rules-of-automatic-semicolon-insertion" title="Rules of Automatic Semicolon Insertion"><span class="secnum">12.10.1</span> Rules of Automatic Semicolon Insertion</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-examples-of-automatic-semicolon-insertion" title="Examples of Automatic Semicolon Insertion"><span class="secnum">12.10.2</span> Examples of Automatic Semicolon Insertion</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-interesting-cases-of-automatic-semicolon-insertion" title="Interesting Cases of Automatic Semicolon Insertion"><span class="secnum">12.10.3</span> Interesting Cases of Automatic Semicolon Insertion</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-asi-interesting-cases-in-statement-lists" title="Interesting Cases of Automatic Semicolon Insertion in Statement Lists"><span class="secnum">12.10.3.1</span> Interesting Cases of Automatic Semicolon Insertion in Statement Lists</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-lexical-grammar.html#sec-asi-cases-with-no-lineterminator-here" title="Cases of Automatic Semicolon Insertion and “[no LineTerminator here]”"><span class="secnum">12.10.3.2</span> Cases of Automatic Semicolon Insertion and “[no <emu-nt>LineTerminator</emu-nt> here]”</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-lexical-grammar.html#sec-no-lineterminator-here-automatic-semicolon-insertion-list" title="List of Grammar Productions with Optional Operands and “[no LineTerminator here]”"><span class="secnum">12.10.3.2.1</span> List of Grammar Productions with Optional Operands and “[no <emu-nt>LineTerminator</emu-nt> here]”</a></li></ol></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-ecmascript-language-expressions" title="ECMAScript Language: Expressions"><span class="secnum">13</span> ECMAScript Language: Expressions</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-identifiers" title="Identifiers"><span class="secnum">13.1</span> Identifiers</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-identifiers-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue" title="Static Semantics: StringValue"><span class="secnum">13.1.2</span> SS: StringValue</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-identifiers-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.1.3</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-primary-expression" title="Primary Expression"><span class="secnum">13.2</span> Primary Expression</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-this-keyword" title="The this Keyword"><span class="secnum">13.2.1</span> The <code>this</code> Keyword</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-this-keyword-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.1.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-identifier-reference" title="Identifier Reference"><span class="secnum">13.2.2</span> Identifier Reference</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-primary-expression-literals" title="Literals"><span class="secnum">13.2.3</span> Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-literals-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.3.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-array-initializer" title="Array Initializer"><span class="secnum">13.2.4</span> Array Initializer</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-arrayaccumulation" title="Runtime Semantics: ArrayAccumulation"><span class="secnum">13.2.4.1</span> RS: ArrayAccumulation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-array-initializer-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.4.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-object-initializer" title="Object Initializer"><span class="secnum">13.2.5</span> Object Initializer</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-object-initializer-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.2.5.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-static-semantics-iscomputedpropertykey" title="Static Semantics: IsComputedPropertyKey"><span class="secnum">13.2.5.2</span> SS: IsComputedPropertyKey</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-static-semantics-propertynamelist" title="Static Semantics: PropertyNameList"><span class="secnum">13.2.5.3</span> SS: PropertyNameList</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-object-initializer-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.5.4</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-propertydefinitionevaluation" title="Runtime Semantics: PropertyDefinitionEvaluation"><span class="secnum">13.2.5.5</span> RS: PropertyDefinitionEvaluation</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-function-defining-expressions" title="Function Defining Expressions"><span class="secnum">13.2.6</span> Function Defining Expressions</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-primary-expression-regular-expression-literals" title="Regular Expression Literals"><span class="secnum">13.2.7</span> Regular Expression Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-primary-expression-regular-expression-literals-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.2.7.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-isvalidregularexpressionliteral" title="Static Semantics: IsValidRegularExpressionLiteral ( literal )"><span class="secnum">13.2.7.2</span> SS: IsValidRegularExpressionLiteral ( <var>literal</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-regular-expression-literals-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.7.3</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-template-literals" title="Template Literals"><span class="secnum">13.2.8</span> Template Literals</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-static-semantics-template-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.2.8.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-static-semantics-templatestrings" title="Static Semantics: TemplateStrings"><span class="secnum">13.2.8.2</span> SS: TemplateStrings</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-templatestring" title="Static Semantics: TemplateString ( templateToken, raw )"><span class="secnum">13.2.8.3</span> SS: TemplateString ( <var>templateToken</var>, <var>raw</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-gettemplateobject" title="GetTemplateObject ( templateLiteral )"><span class="secnum">13.2.8.4</span> GetTemplateObject ( <var>templateLiteral</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-substitutionevaluation" title="Runtime Semantics: SubstitutionEvaluation"><span class="secnum">13.2.8.5</span> RS: SubstitutionEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-template-literals-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.8.6</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-grouping-operator" title="The Grouping Operator"><span class="secnum">13.2.9</span> The Grouping Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-grouping-operator-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.2.9.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-grouping-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.2.9.2</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-left-hand-side-expressions" title="Left-Hand-Side Expressions"><span class="secnum">13.3</span> Left-Hand-Side Expressions</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-static-semantics" title="Static Semantics"><span class="secnum">13.3.1</span> Static Semantics</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-left-hand-side-expressions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.3.1.1</span> SS: Early Errors</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-property-accessors" title="Property Accessors"><span class="secnum">13.3.2</span> Property Accessors</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-property-accessors-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.2.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-evaluate-property-access-with-expression-key" title="EvaluatePropertyAccessWithExpressionKey ( baseValue, expression, strict )"><span class="secnum">13.3.3</span> EvaluatePropertyAccessWithExpressionKey ( <var>baseValue</var>, <var>expression</var>, <var>strict</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-evaluate-property-access-with-identifier-key" title="EvaluatePropertyAccessWithIdentifierKey ( baseValue, identifierName, strict )"><span class="secnum">13.3.4</span> EvaluatePropertyAccessWithIdentifierKey ( <var>baseValue</var>, <var>identifierName</var>, <var>strict</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-new-operator" title="The new Operator"><span class="secnum">13.3.5</span> The <code>new</code> Operator</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-new-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.5.1</span> RS: Evaluation</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-evaluatenew" title="EvaluateNew ( constructExpr, arguments )"><span class="secnum">13.3.5.1.1</span> EvaluateNew ( <var>constructExpr</var>, <var>arguments</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-function-calls" title="Function Calls"><span class="secnum">13.3.6</span> Function Calls</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-function-calls-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.6.1</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-evaluatecall" title="EvaluateCall ( func, ref, arguments, tailPosition )"><span class="secnum">13.3.6.2</span> EvaluateCall ( <var>func</var>, <var>ref</var>, <var>arguments</var>, <var>tailPosition</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-super-keyword" title="The super Keyword"><span class="secnum">13.3.7</span> The <code>super</code> Keyword</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-super-keyword-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.7.1</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-getsuperconstructor" title="GetSuperConstructor ( )"><span class="secnum">13.3.7.2</span> GetSuperConstructor ( )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-makesuperpropertyreference" title="MakeSuperPropertyReference ( actualThis, propertyKey, strict )"><span class="secnum">13.3.7.3</span> MakeSuperPropertyReference ( <var>actualThis</var>, <var>propertyKey</var>, <var>strict</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-argument-lists" title="Argument Lists"><span class="secnum">13.3.8</span> Argument Lists</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-argumentlistevaluation" title="Runtime Semantics: ArgumentListEvaluation"><span class="secnum">13.3.8.1</span> RS: ArgumentListEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-optional-chains" title="Optional Chains"><span class="secnum">13.3.9</span> Optional Chains</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-optional-chaining-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.9.1</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-optional-chaining-chain-evaluation" title="Runtime Semantics: ChainEvaluation"><span class="secnum">13.3.9.2</span> RS: ChainEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-import-calls" title="Import Calls"><span class="secnum">13.3.10</span> Import Calls</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-import-call-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.10.1</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-evaluate-import-call" title="EvaluateImportCall ( specifierExpression [ , optionsExpression ] )"><span class="secnum">13.3.10.2</span> EvaluateImportCall ( <var>specifierExpression</var> [ , <var>optionsExpression</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-ContinueDynamicImport" title="ContinueDynamicImport ( promiseCapability, moduleCompletion )"><span class="secnum">13.3.10.3</span> ContinueDynamicImport ( <var>promiseCapability</var>, <var>moduleCompletion</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-tagged-templates" title="Tagged Templates"><span class="secnum">13.3.11</span> Tagged Templates</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-tagged-templates-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.11.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-meta-properties" title="Meta Properties"><span class="secnum">13.3.12</span> Meta Properties</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-meta-properties-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.3.12.1</span> RS: Evaluation</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-hostgetimportmetaproperties" title="HostGetImportMetaProperties ( moduleRecord )"><span class="secnum">13.3.12.1.1</span> HostGetImportMetaProperties ( <var>moduleRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-hostfinalizeimportmeta" title="HostFinalizeImportMeta ( importMeta, moduleRecord )"><span class="secnum">13.3.12.1.2</span> HostFinalizeImportMeta ( <var>importMeta</var>, <var>moduleRecord</var> )</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-update-expressions" title="Update Expressions"><span class="secnum">13.4</span> Update Expressions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-update-expressions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.4.1</span> SS: Early Errors</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-postfix-increment-operator" title="Postfix Increment Operator"><span class="secnum">13.4.2</span> Postfix Increment Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-postfix-increment-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.4.2.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-postfix-decrement-operator" title="Postfix Decrement Operator"><span class="secnum">13.4.3</span> Postfix Decrement Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-postfix-decrement-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.4.3.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-prefix-increment-operator" title="Prefix Increment Operator"><span class="secnum">13.4.4</span> Prefix Increment Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-prefix-increment-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.4.4.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-prefix-decrement-operator" title="Prefix Decrement Operator"><span class="secnum">13.4.5</span> Prefix Decrement Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-prefix-decrement-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.4.5.1</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-unary-operators" title="Unary Operators"><span class="secnum">13.5</span> Unary Operators</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-delete-operator" title="The delete Operator"><span class="secnum">13.5.1</span> The <code>delete</code> Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-delete-operator-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.5.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-delete-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.1.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-void-operator" title="The void Operator"><span class="secnum">13.5.2</span> The <code>void</code> Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-void-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.2.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-typeof-operator" title="The typeof Operator"><span class="secnum">13.5.3</span> The <code>typeof</code> Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-typeof-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.3.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-unary-plus-operator" title="Unary + Operator"><span class="secnum">13.5.4</span> Unary <code>+</code> Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-unary-plus-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.4.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-unary-minus-operator" title="Unary - Operator"><span class="secnum">13.5.5</span> Unary <code>-</code> Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-unary-minus-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.5.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-bitwise-not-operator" title="Bitwise NOT Operator ( ~ )"><span class="secnum">13.5.6</span> Bitwise NOT Operator ( <code>~</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-bitwise-not-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.6.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-logical-not-operator" title="Logical NOT Operator ( ! )"><span class="secnum">13.5.7</span> Logical NOT Operator ( <code>!</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-logical-not-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.5.7.1</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-exp-operator" title="Exponentiation Operator"><span class="secnum">13.6</span> Exponentiation Operator</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-exp-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.6.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-multiplicative-operators" title="Multiplicative Operators"><span class="secnum">13.7</span> Multiplicative Operators</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-multiplicative-operators-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.7.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-additive-operators" title="Additive Operators"><span class="secnum">13.8</span> Additive Operators</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-addition-operator-plus" title="The Addition Operator ( + )"><span class="secnum">13.8.1</span> The Addition Operator ( <code>+</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-addition-operator-plus-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.8.1.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-subtraction-operator-minus" title="The Subtraction Operator ( - )"><span class="secnum">13.8.2</span> The Subtraction Operator ( <code>-</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-subtraction-operator-minus-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.8.2.1</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-bitwise-shift-operators" title="Bitwise Shift Operators"><span class="secnum">13.9</span> Bitwise Shift Operators</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-left-shift-operator" title="The Left Shift Operator ( << )"><span class="secnum">13.9.1</span> The Left Shift Operator ( <code>&lt;&lt;</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-left-shift-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.9.1.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-signed-right-shift-operator" title="The Signed Right Shift Operator ( >> )"><span class="secnum">13.9.2</span> The Signed Right Shift Operator ( <code>&gt;&gt;</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-signed-right-shift-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.9.2.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-unsigned-right-shift-operator" title="The Unsigned Right Shift Operator ( >>> )"><span class="secnum">13.9.3</span> The Unsigned Right Shift Operator ( <code>&gt;&gt;&gt;</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-unsigned-right-shift-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.9.3.1</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-relational-operators" title="Relational Operators"><span class="secnum">13.10</span> Relational Operators</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-relational-operators-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.10.1</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-instanceofoperator" title="InstanceofOperator ( V, target )"><span class="secnum">13.10.2</span> InstanceofOperator ( <var>V</var>, <var>target</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-equality-operators" title="Equality Operators"><span class="secnum">13.11</span> Equality Operators</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-equality-operators-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.11.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-binary-bitwise-operators" title="Binary Bitwise Operators"><span class="secnum">13.12</span> Binary Bitwise Operators</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-binary-bitwise-operators-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.12.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-binary-logical-operators" title="Binary Logical Operators"><span class="secnum">13.13</span> Binary Logical Operators</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-binary-logical-operators-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.13.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-conditional-operator" title="Conditional Operator ( ? : )"><span class="secnum">13.14</span> Conditional Operator ( <code>? :</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-conditional-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.14.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-assignment-operators" title="Assignment Operators"><span class="secnum">13.15</span> Assignment Operators</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-assignment-operators-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.15.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-assignment-operators-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.15.2</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-applystringornumericbinaryoperator" title="ApplyStringOrNumericBinaryOperator ( lVal, opText, rVal )"><span class="secnum">13.15.3</span> ApplyStringOrNumericBinaryOperator ( <var>lVal</var>, <var>opText</var>, <var>rVal</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-evaluatestringornumericbinaryexpression" title="EvaluateStringOrNumericBinaryExpression ( leftOperand, opText, rightOperand )"><span class="secnum">13.15.4</span> EvaluateStringOrNumericBinaryExpression ( <var>leftOperand</var>, <var>opText</var>, <var>rightOperand</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-destructuring-assignment" title="Destructuring Assignment"><span class="secnum">13.15.5</span> Destructuring Assignment</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-destructuring-assignment-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">13.15.5.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-destructuringassignmentevaluation" title="Runtime Semantics: DestructuringAssignmentEvaluation"><span class="secnum">13.15.5.2</span> RS: DestructuringAssignmentEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-propertydestructuringassignmentevaluation" title="Runtime Semantics: PropertyDestructuringAssignmentEvaluation"><span class="secnum">13.15.5.3</span> RS: PropertyDestructuringAssignmentEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-restdestructuringassignmentevaluation" title="Runtime Semantics: RestDestructuringAssignmentEvaluation"><span class="secnum">13.15.5.4</span> RS: RestDestructuringAssignmentEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-iteratordestructuringassignmentevaluation" title="Runtime Semantics: IteratorDestructuringAssignmentEvaluation"><span class="secnum">13.15.5.5</span> RS: IteratorDestructuringAssignmentEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-runtime-semantics-keyeddestructuringassignmentevaluation" title="Runtime Semantics: KeyedDestructuringAssignmentEvaluation"><span class="secnum">13.15.5.6</span> RS: KeyedDestructuringAssignmentEvaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-expressions.html#sec-comma-operator" title="Comma Operator ( , )"><span class="secnum">13.16</span> Comma Operator ( <code>,</code> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-expressions.html#sec-comma-operator-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">13.16.1</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-ecmascript-language-statements-and-declarations" title="ECMAScript Language: Statements and Declarations"><span class="secnum">14</span> ECMAScript Language: Statements and Declarations</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-statement-semantics" title="Statement Semantics"><span class="secnum">14.1</span> Statement Semantics</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-statement-semantics-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.1.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-block" title="Block"><span class="secnum">14.2</span> Block</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-block-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.2.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-block-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.2.2</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-blockdeclarationinstantiation" title="BlockDeclarationInstantiation ( code, env )"><span class="secnum">14.2.3</span> BlockDeclarationInstantiation ( <var>code</var>, <var>env</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-declarations-and-the-variable-statement" title="Declarations and the Variable Statement"><span class="secnum">14.3</span> Declarations and the Variable Statement</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-let-and-const-declarations" title="Let and Const Declarations"><span class="secnum">14.3.1</span> Let and Const Declarations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-let-and-const-declarations-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.3.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-let-and-const-declarations-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.3.1.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-variable-statement" title="Variable Statement"><span class="secnum">14.3.2</span> Variable Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-variable-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.3.2.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-destructuring-binding-patterns" title="Destructuring Binding Patterns"><span class="secnum">14.3.3</span> Destructuring Binding Patterns</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-destructuring-binding-patterns-runtime-semantics-propertybindinginitialization" title="Runtime Semantics: PropertyBindingInitialization"><span class="secnum">14.3.3.1</span> RS: PropertyBindingInitialization</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-destructuring-binding-patterns-runtime-semantics-restbindinginitialization" title="Runtime Semantics: RestBindingInitialization"><span class="secnum">14.3.3.2</span> RS: RestBindingInitialization</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-keyedbindinginitialization" title="Runtime Semantics: KeyedBindingInitialization"><span class="secnum">14.3.3.3</span> RS: KeyedBindingInitialization</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-empty-statement" title="Empty Statement"><span class="secnum">14.4</span> Empty Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-empty-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.4.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-expression-statement" title="Expression Statement"><span class="secnum">14.5</span> Expression Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-expression-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.5.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-if-statement" title="The if Statement"><span class="secnum">14.6</span> The <code>if</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-if-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.6.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-if-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.6.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-iteration-statements" title="Iteration Statements"><span class="secnum">14.7</span> Iteration Statements</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-iteration-statements-semantics" title="Semantics"><span class="secnum">14.7.1</span> Semantics</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-loopcontinues" title="LoopContinues ( completion, labelSet )"><span class="secnum">14.7.1.1</span> LoopContinues ( <var>completion</var>, <var>labelSet</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-loopevaluation" title="Runtime Semantics: LoopEvaluation"><span class="secnum">14.7.1.2</span> RS: LoopEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-do-while-statement" title="The do-while Statement"><span class="secnum">14.7.2</span> The <code>do</code>-<code>while</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-do-while-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.7.2.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-dowhileloopevaluation" title="Runtime Semantics: DoWhileLoopEvaluation"><span class="secnum">14.7.2.2</span> RS: DoWhileLoopEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-while-statement" title="The while Statement"><span class="secnum">14.7.3</span> The <code>while</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-while-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.7.3.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-whileloopevaluation" title="Runtime Semantics: WhileLoopEvaluation"><span class="secnum">14.7.3.2</span> RS: WhileLoopEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-for-statement" title="The for Statement"><span class="secnum">14.7.4</span> The <code>for</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-for-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.7.4.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forloopevaluation" title="Runtime Semantics: ForLoopEvaluation"><span class="secnum">14.7.4.2</span> RS: ForLoopEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-forbodyevaluation" title="ForBodyEvaluation ( test, increment, stmt, perIterationBindings, labelSet )"><span class="secnum">14.7.4.3</span> ForBodyEvaluation ( <var>test</var>, <var>increment</var>, <var>stmt</var>, <var>perIterationBindings</var>, <var>labelSet</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-createperiterationenvironment" title="CreatePerIterationEnvironment ( perIterationBindings )"><span class="secnum">14.7.4.4</span> CreatePerIterationEnvironment ( <var>perIterationBindings</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-and-for-of-statements" title="The for-in, for-of, and for-await-of Statements"><span class="secnum">14.7.5</span> The <code>for</code>-<code>in</code>, <code>for</code>-<code>of</code>, and <code>for</code>-<code>await</code>-<code>of</code> Statements</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-and-for-of-statements-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.7.5.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-static-semantics-isdestructuring" title="Static Semantics: IsDestructuring"><span class="secnum">14.7.5.2</span> SS: IsDestructuring</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-fordeclarationbindinginitialization" title="Runtime Semantics: ForDeclarationBindingInitialization"><span class="secnum">14.7.5.3</span> RS: ForDeclarationBindingInitialization</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-fordeclarationbindinginstantiation" title="Runtime Semantics: ForDeclarationBindingInstantiation"><span class="secnum">14.7.5.4</span> RS: ForDeclarationBindingInstantiation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofloopevaluation" title="Runtime Semantics: ForInOfLoopEvaluation"><span class="secnum">14.7.5.5</span> RS: ForInOfLoopEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" title="ForIn/OfHeadEvaluation ( uninitializedBoundNames, expr, iterationKind )"><span class="secnum">14.7.5.6</span> ForIn/OfHeadEvaluation ( <var>uninitializedBoundNames</var>, <var>expr</var>, <var>iterationKind</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" title="ForIn/OfBodyEvaluation ( lhs, stmt, iteratorRecord, iterationKind, lhsKind, labelSet [ , iteratorKind ] )"><span class="secnum">14.7.5.7</span> ForIn/OfBodyEvaluation ( <var>lhs</var>, <var>stmt</var>, <var>iteratorRecord</var>, <var>iterationKind</var>, <var>lhsKind</var>, <var>labelSet</var> [ , <var>iteratorKind</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-and-for-of-statements-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.7.5.8</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-enumerate-object-properties" title="EnumerateObjectProperties ( O )"><span class="secnum">14.7.5.9</span> EnumerateObjectProperties ( <var>O</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects" title="For-In Iterator Objects"><span class="secnum">14.7.5.10</span> For-In Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-createforiniterator" title="CreateForInIterator ( object )"><span class="secnum">14.7.5.10.1</span> CreateForInIterator ( <var>object</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-%foriniteratorprototype%-object" title="The %ForInIteratorPrototype% Object"><span class="secnum">14.7.5.10.2</span> The %ForInIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-%foriniteratorprototype%.next" title="%ForInIteratorPrototype%.next ( )"><span class="secnum">14.7.5.10.2.1</span> %ForInIteratorPrototype%.next ( )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-properties-of-for-in-iterator-instances" title="Properties of For-In Iterator Instances"><span class="secnum">14.7.5.10.3</span> Properties of For-In Iterator Instances</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-continue-statement" title="The continue Statement"><span class="secnum">14.8</span> The <code>continue</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-continue-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.8.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-continue-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.8.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-break-statement" title="The break Statement"><span class="secnum">14.9</span> The <code>break</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-break-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.9.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-break-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.9.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-return-statement" title="The return Statement"><span class="secnum">14.10</span> The <code>return</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-return-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.10.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-with-statement" title="The with Statement"><span class="secnum">14.11</span> The <code>with</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-with-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.11.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-with-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.11.2</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-switch-statement" title="The switch Statement"><span class="secnum">14.12</span> The <code>switch</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-switch-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.12.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-caseblockevaluation" title="Runtime Semantics: CaseBlockEvaluation"><span class="secnum">14.12.2</span> RS: CaseBlockEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-caseclauseisselected" title="CaseClauseIsSelected ( C, input )"><span class="secnum">14.12.3</span> CaseClauseIsSelected ( <var>C</var>, <var>input</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-switch-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.12.4</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-labelled-statements" title="Labelled Statements"><span class="secnum">14.13</span> Labelled Statements</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-labelled-statements-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.13.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction" title="Static Semantics: IsLabelledFunction ( stmt )"><span class="secnum">14.13.2</span> SS: IsLabelledFunction ( <var>stmt</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-labelled-statements-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.13.3</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-labelledevaluation" title="Runtime Semantics: LabelledEvaluation"><span class="secnum">14.13.4</span> RS: LabelledEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-throw-statement" title="The throw Statement"><span class="secnum">14.14</span> The <code>throw</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-throw-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.14.1</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-try-statement" title="The try Statement"><span class="secnum">14.15</span> The <code>try</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-try-statement-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">14.15.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-catchclauseevaluation" title="Runtime Semantics: CatchClauseEvaluation"><span class="secnum">14.15.2</span> RS: CatchClauseEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-try-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.15.3</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-statements-and-declarations.html#sec-debugger-statement" title="The debugger Statement"><span class="secnum">14.16</span> The <code>debugger</code> Statement</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-statements-and-declarations.html#sec-debugger-statement-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">14.16.1</span> RS: Evaluation</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-ecmascript-language-functions-and-classes" title="ECMAScript Language: Functions and Classes"><span class="secnum">15</span> ECMAScript Language: Functions and Classes</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-parameter-lists" title="Parameter Lists"><span class="secnum">15.1</span> Parameter Lists</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-parameter-lists-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-containsexpression" title="Static Semantics: ContainsExpression"><span class="secnum">15.1.2</span> SS: ContainsExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-issimpleparameterlist" title="Static Semantics: IsSimpleParameterList"><span class="secnum">15.1.3</span> SS: IsSimpleParameterList</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-hasinitializer" title="Static Semantics: HasInitializer"><span class="secnum">15.1.4</span> SS: HasInitializer</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-expectedargumentcount" title="Static Semantics: ExpectedArgumentCount"><span class="secnum">15.1.5</span> SS: ExpectedArgumentCount</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-function-definitions" title="Function Definitions"><span class="secnum">15.2</span> Function Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-function-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.2.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-functionbodycontainsusestrict" title="Static Semantics: FunctionBodyContainsUseStrict"><span class="secnum">15.2.2</span> SS: FunctionBodyContainsUseStrict</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluatefunctionbody" title="Runtime Semantics: EvaluateFunctionBody"><span class="secnum">15.2.3</span> RS: EvaluateFunctionBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateordinaryfunctionobject" title="Runtime Semantics: InstantiateOrdinaryFunctionObject"><span class="secnum">15.2.4</span> RS: InstantiateOrdinaryFunctionObject</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateordinaryfunctionexpression" title="Runtime Semantics: InstantiateOrdinaryFunctionExpression"><span class="secnum">15.2.5</span> RS: InstantiateOrdinaryFunctionExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-function-definitions-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.2.6</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-arrow-function-definitions" title="Arrow Function Definitions"><span class="secnum">15.3</span> Arrow Function Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-arrow-function-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.3.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-concisebodycontainsusestrict" title="Static Semantics: ConciseBodyContainsUseStrict"><span class="secnum">15.3.2</span> SS: ConciseBodyContainsUseStrict</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluateconcisebody" title="Runtime Semantics: EvaluateConciseBody"><span class="secnum">15.3.3</span> RS: EvaluateConciseBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiatearrowfunctionexpression" title="Runtime Semantics: InstantiateArrowFunctionExpression"><span class="secnum">15.3.4</span> RS: InstantiateArrowFunctionExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-arrow-function-definitions-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.3.5</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-method-definitions" title="Method Definitions"><span class="secnum">15.4</span> Method Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-method-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.4.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-hasdirectsuper" title="Static Semantics: HasDirectSuper"><span class="secnum">15.4.2</span> SS: HasDirectSuper</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-specialmethod" title="Static Semantics: SpecialMethod"><span class="secnum">15.4.3</span> SS: SpecialMethod</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-definemethod" title="Runtime Semantics: DefineMethod"><span class="secnum">15.4.4</span> RS: DefineMethod</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-methoddefinitionevaluation" title="Runtime Semantics: MethodDefinitionEvaluation"><span class="secnum">15.4.5</span> RS: MethodDefinitionEvaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-generator-function-definitions" title="Generator Function Definitions"><span class="secnum">15.5</span> Generator Function Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-generator-function-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.5.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluategeneratorbody" title="Runtime Semantics: EvaluateGeneratorBody"><span class="secnum">15.5.2</span> RS: EvaluateGeneratorBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiategeneratorfunctionobject" title="Runtime Semantics: InstantiateGeneratorFunctionObject"><span class="secnum">15.5.3</span> RS: InstantiateGeneratorFunctionObject</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiategeneratorfunctionexpression" title="Runtime Semantics: InstantiateGeneratorFunctionExpression"><span class="secnum">15.5.4</span> RS: InstantiateGeneratorFunctionExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-generator-function-definitions-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.5.5</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-async-generator-function-definitions" title="Async Generator Function Definitions"><span class="secnum">15.6</span> Async Generator Function Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-async-generator-function-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.6.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluateasyncgeneratorbody" title="Runtime Semantics: EvaluateAsyncGeneratorBody"><span class="secnum">15.6.2</span> RS: EvaluateAsyncGeneratorBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateasyncgeneratorfunctionobject" title="Runtime Semantics: InstantiateAsyncGeneratorFunctionObject"><span class="secnum">15.6.3</span> RS: InstantiateAsyncGeneratorFunctionObject</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateasyncgeneratorfunctionexpression" title="Runtime Semantics: InstantiateAsyncGeneratorFunctionExpression"><span class="secnum">15.6.4</span> RS: InstantiateAsyncGeneratorFunctionExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-asyncgenerator-definitions-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.6.5</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-class-definitions" title="Class Definitions"><span class="secnum">15.7</span> Class Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-class-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.7.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-classelementkind" title="Static Semantics: ClassElementKind"><span class="secnum">15.7.2</span> SS: ClassElementKind</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-constructormethod" title="Static Semantics: ConstructorMethod"><span class="secnum">15.7.3</span> SS: ConstructorMethod</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-isstatic" title="Static Semantics: IsStatic"><span class="secnum">15.7.4</span> SS: IsStatic</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-nonconstructorelements" title="Static Semantics: NonConstructorElements"><span class="secnum">15.7.5</span> SS: NonConstructorElements</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-prototypepropertynamelist" title="Static Semantics: PrototypePropertyNameList"><span class="secnum">15.7.6</span> SS: PrototypePropertyNameList</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-allprivateidentifiersvalid" title="Static Semantics: AllPrivateIdentifiersValid"><span class="secnum">15.7.7</span> SS: AllPrivateIdentifiersValid</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-privateboundidentifiers" title="Static Semantics: PrivateBoundIdentifiers"><span class="secnum">15.7.8</span> SS: PrivateBoundIdentifiers</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-containsarguments" title="Static Semantics: ContainsArguments"><span class="secnum">15.7.9</span> SS: ContainsArguments</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-classfielddefinitionevaluation" title="Runtime Semantics: ClassFieldDefinitionEvaluation"><span class="secnum">15.7.10</span> RS: ClassFieldDefinitionEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-classstaticblockdefinitionevaluation" title="Runtime Semantics: ClassStaticBlockDefinitionEvaluation"><span class="secnum">15.7.11</span> RS: ClassStaticBlockDefinitionEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluateclassstaticblockbody" title="Runtime Semantics: EvaluateClassStaticBlockBody"><span class="secnum">15.7.12</span> RS: EvaluateClassStaticBlockBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-classelementevaluation" title="Runtime Semantics: ClassElementEvaluation"><span class="secnum">15.7.13</span> RS: ClassElementEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-classdefinitionevaluation" title="Runtime Semantics: ClassDefinitionEvaluation"><span class="secnum">15.7.14</span> RS: ClassDefinitionEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-bindingclassdeclarationevaluation" title="Runtime Semantics: BindingClassDeclarationEvaluation"><span class="secnum">15.7.15</span> RS: BindingClassDeclarationEvaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-class-definitions-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.7.16</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-async-function-definitions" title="Async Function Definitions"><span class="secnum">15.8</span> Async Function Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-async-function-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.8.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateasyncfunctionobject" title="Runtime Semantics: InstantiateAsyncFunctionObject"><span class="secnum">15.8.2</span> RS: InstantiateAsyncFunctionObject</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateasyncfunctionexpression" title="Runtime Semantics: InstantiateAsyncFunctionExpression"><span class="secnum">15.8.3</span> RS: InstantiateAsyncFunctionExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluateasyncfunctionbody" title="Runtime Semantics: EvaluateAsyncFunctionBody"><span class="secnum">15.8.4</span> RS: EvaluateAsyncFunctionBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-async-function-definitions-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.8.5</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-async-arrow-function-definitions" title="Async Arrow Function Definitions"><span class="secnum">15.9</span> Async Arrow Function Definitions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-async-arrow-function-definitions-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">15.9.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-asyncconcisebodycontainsusestrict" title="Static Semantics: AsyncConciseBodyContainsUseStrict"><span class="secnum">15.9.2</span> SS: AsyncConciseBodyContainsUseStrict</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-evaluateasyncconcisebody" title="Runtime Semantics: EvaluateAsyncConciseBody"><span class="secnum">15.9.3</span> RS: EvaluateAsyncConciseBody</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-runtime-semantics-instantiateasyncarrowfunctionexpression" title="Runtime Semantics: InstantiateAsyncArrowFunctionExpression"><span class="secnum">15.9.4</span> RS: InstantiateAsyncArrowFunctionExpression</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-async-arrow-function-definitions-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">15.9.5</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-functions-and-classes.html#sec-tail-position-calls" title="Tail Position Calls"><span class="secnum">15.10</span> Tail Position Calls</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-isintailposition" title="Static Semantics: IsInTailPosition ( call )"><span class="secnum">15.10.1</span> SS: IsInTailPosition ( <var>call</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-static-semantics-hascallintailposition" title="Static Semantics: HasCallInTailPosition"><span class="secnum">15.10.2</span> SS: HasCallInTailPosition</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-functions-and-classes.html#sec-preparefortailcall" title="PrepareForTailCall ( )"><span class="secnum">15.10.3</span> PrepareForTailCall ( )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-ecmascript-language-scripts-and-modules" title="ECMAScript Language: Scripts and Modules"><span class="secnum">16</span> ECMAScript Language: Scripts and Modules</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-scripts" title="Scripts"><span class="secnum">16.1</span> Scripts</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-scripts-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">16.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-scriptisstrict" title="Static Semantics: ScriptIsStrict"><span class="secnum">16.1.2</span> SS: ScriptIsStrict</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-script-semantics-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">16.1.3</span> RS: Evaluation</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-script-records" title="Script Records"><span class="secnum">16.1.4</span> Script Records</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-parse-script" title="ParseScript ( sourceText, realm, hostDefined )"><span class="secnum">16.1.5</span> ParseScript ( <var>sourceText</var>, <var>realm</var>, <var>hostDefined</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-runtime-semantics-scriptevaluation" title="ScriptEvaluation ( scriptRecord )"><span class="secnum">16.1.6</span> ScriptEvaluation ( <var>scriptRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-globaldeclarationinstantiation" title="GlobalDeclarationInstantiation ( script, env )"><span class="secnum">16.1.7</span> GlobalDeclarationInstantiation ( <var>script</var>, <var>env</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-modules" title="Modules"><span class="secnum">16.2</span> Modules</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-module-semantics" title="Module Semantics"><span class="secnum">16.2.1</span> Module Semantics</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-module-semantics-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">16.2.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-importedlocalnames" title="Static Semantics: ImportedLocalNames ( importEntries )"><span class="secnum">16.2.1.2</span> SS: ImportedLocalNames ( <var>importEntries</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-modulerequest-record" title="ModuleRequest Records"><span class="secnum">16.2.1.3</span> ModuleRequest Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-ModuleRequestsEqual" title="ModuleRequestsEqual ( left, right )"><span class="secnum">16.2.1.3.1</span> ModuleRequestsEqual ( <var>left</var>, <var>right</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-modulerequests" title="Static Semantics: ModuleRequests"><span class="secnum">16.2.1.4</span> SS: ModuleRequests</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-abstract-module-records" title="Abstract Module Records"><span class="secnum">16.2.1.5</span> Abstract Module Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-EvaluateModuleSync" title="EvaluateModuleSync ( module )"><span class="secnum">16.2.1.5.1</span> EvaluateModuleSync ( <var>module</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-cyclic-module-records" title="Cyclic Module Records"><span class="secnum">16.2.1.6</span> Cyclic Module Records</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-cyclic-module-record-module-record-methods" title="Implementation of Module Record Abstract Methods"><span class="secnum">16.2.1.6.1</span> Implementation of Module Record Abstract Methods</a><ol class="toc"><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-LoadRequestedModules" title="LoadRequestedModules ( [ hostDefined ] )"><span class="secnum">16.2.1.6.1.1</span> LoadRequestedModules ( [ <var>hostDefined</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-InnerModuleLoading" title="InnerModuleLoading ( state, module )"><span class="secnum">16.2.1.6.1.1.1</span> InnerModuleLoading ( <var>state</var>, <var>module</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-ContinueModuleLoading" title="ContinueModuleLoading ( state, moduleCompletion )"><span class="secnum">16.2.1.6.1.1.2</span> ContinueModuleLoading ( <var>state</var>, <var>moduleCompletion</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-moduledeclarationlinking" title="Link ( )"><span class="secnum">16.2.1.6.1.2</span> Link ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-InnerModuleLinking" title="InnerModuleLinking ( module, stack, index )"><span class="secnum">16.2.1.6.1.2.1</span> InnerModuleLinking ( <var>module</var>, <var>stack</var>, <var>index</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-moduleevaluation" title="Evaluate ( )"><span class="secnum">16.2.1.6.1.3</span> Evaluate ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-innermoduleevaluation" title="InnerModuleEvaluation ( module, stack, index )"><span class="secnum">16.2.1.6.1.3.1</span> InnerModuleEvaluation ( <var>module</var>, <var>stack</var>, <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-execute-async-module" title="ExecuteAsyncModule ( module )"><span class="secnum">16.2.1.6.1.3.2</span> ExecuteAsyncModule ( <var>module</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-gather-available-ancestors" title="GatherAvailableAncestors ( module, execList )"><span class="secnum">16.2.1.6.1.3.3</span> GatherAvailableAncestors ( <var>module</var>, <var>execList</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-async-module-execution-fulfilled" title="AsyncModuleExecutionFulfilled ( module )"><span class="secnum">16.2.1.6.1.3.4</span> AsyncModuleExecutionFulfilled ( <var>module</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-async-module-execution-rejected" title="AsyncModuleExecutionRejected ( module, error )"><span class="secnum">16.2.1.6.1.3.5</span> AsyncModuleExecutionRejected ( <var>module</var>, <var>error</var> )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-example-cyclic-module-record-graphs" title="Example Cyclic Module Record Graphs"><span class="secnum">16.2.1.6.2</span> Example Cyclic Module Record Graphs</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-source-text-module-records" title="Source Text Module Records"><span class="secnum">16.2.1.7</span> Source Text Module Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-parsemodule" title="ParseModule ( sourceText, realm, hostDefined )"><span class="secnum">16.2.1.7.1</span> ParseModule ( <var>sourceText</var>, <var>realm</var>, <var>hostDefined</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-source-text-module-record-module-record-methods" title="Implementation of Module Record Abstract Methods"><span class="secnum">16.2.1.7.2</span> Implementation of Module Record Abstract Methods</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-getexportednames" title="GetExportedNames ( [ exportStarSet ] )"><span class="secnum">16.2.1.7.2.1</span> GetExportedNames ( [ <var>exportStarSet</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-resolveexport" title="ResolveExport ( exportName [ , resolveSet ] )"><span class="secnum">16.2.1.7.2.2</span> ResolveExport ( <var>exportName</var> [ , <var>resolveSet</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-source-text-module-record-cyclic-module-record-methods" title="Implementation of Cyclic Module Record Abstract Methods"><span class="secnum">16.2.1.7.3</span> Implementation of Cyclic Module Record Abstract Methods</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-source-text-module-record-initialize-environment" title="InitializeEnvironment ( )"><span class="secnum">16.2.1.7.3.1</span> InitializeEnvironment ( )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-source-text-module-record-execute-module" title="ExecuteModule ( [ capability ] )"><span class="secnum">16.2.1.7.3.2</span> ExecuteModule ( [ <var>capability</var> ] )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-synthetic-module-records" title="Synthetic Module Records"><span class="secnum">16.2.1.8</span> Synthetic Module Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-create-default-export-synthetic-module" title="CreateDefaultExportSyntheticModule ( defaultExport )"><span class="secnum">16.2.1.8.1</span> CreateDefaultExportSyntheticModule ( <var>defaultExport</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-parse-json-module" title="ParseJSONModule ( source )"><span class="secnum">16.2.1.8.2</span> ParseJSONModule ( <var>source</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-setsyntheticmoduleexport" title="SetSyntheticModuleExport ( module, exportName, exportValue )"><span class="secnum">16.2.1.8.3</span> SetSyntheticModuleExport ( <var>module</var>, <var>exportName</var>, <var>exportValue</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-smr-module-record-methods" title="Implementation of Module Record Abstract Methods"><span class="secnum">16.2.1.8.4</span> Implementation of Module Record Abstract Methods</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-smr-LoadRequestedModules" title="LoadRequestedModules ( [ hostDefined ] )"><span class="secnum">16.2.1.8.4.1</span> LoadRequestedModules ( [ <var>hostDefined</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-smr-getexportednames" title="GetExportedNames ( [ exportStarSet ] )"><span class="secnum">16.2.1.8.4.2</span> GetExportedNames ( [ <var>exportStarSet</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-smr-resolveexport" title="ResolveExport ( exportName [ , resolveSet ] )"><span class="secnum">16.2.1.8.4.3</span> ResolveExport ( <var>exportName</var> [ , <var>resolveSet</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-smr-Link" title="Link ( )"><span class="secnum">16.2.1.8.4.4</span> Link ( )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-smr-Evaluate" title="Evaluate ( )"><span class="secnum">16.2.1.8.4.5</span> Evaluate ( )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-GetImportedModule" title="GetImportedModule ( referrer, request )"><span class="secnum">16.2.1.9</span> GetImportedModule ( <var>referrer</var>, <var>request</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-HostLoadImportedModule" title="HostLoadImportedModule ( referrer, moduleRequest, hostDefined, payload )"><span class="secnum">16.2.1.10</span> HostLoadImportedModule ( <var>referrer</var>, <var>moduleRequest</var>, <var>hostDefined</var>, <var>payload</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-FinishLoadingImportedModule" title="FinishLoadingImportedModule ( referrer, moduleRequest, payload, result )"><span class="secnum">16.2.1.11</span> FinishLoadingImportedModule ( <var>referrer</var>, <var>moduleRequest</var>, <var>payload</var>, <var>result</var> )</a></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-AllImportAttributesSupported" title="AllImportAttributesSupported ( attributes )"><span class="secnum">16.2.1.12</span> AllImportAttributesSupported ( <var>attributes</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-hostgetsupportedimportattributes" title="HostGetSupportedImportAttributes ( )"><span class="secnum">16.2.1.12.1</span> HostGetSupportedImportAttributes ( )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-getmodulenamespace" title="GetModuleNamespace ( module )"><span class="secnum">16.2.1.13</span> GetModuleNamespace ( <var>module</var> )</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-module-semantics-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">16.2.1.14</span> RS: Evaluation</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-imports" title="Imports"><span class="secnum">16.2.2</span> Imports</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-imports-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">16.2.2.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-importentries" title="Static Semantics: ImportEntries"><span class="secnum">16.2.2.2</span> SS: ImportEntries</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-importentriesformodule" title="Static Semantics: ImportEntriesForModule"><span class="secnum">16.2.2.3</span> SS: ImportEntriesForModule</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-withclausetoattributes" title="Static Semantics: WithClauseToAttributes"><span class="secnum">16.2.2.4</span> SS: WithClauseToAttributes</a></li></ol></li><li><span class="item-toggle">+</span><a href="ecmascript-language-scripts-and-modules.html#sec-exports" title="Exports"><span class="secnum">16.2.3</span> Exports</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-exports-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">16.2.3.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-exportedbindings" title="Static Semantics: ExportedBindings"><span class="secnum">16.2.3.2</span> SS: ExportedBindings</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-exportednames" title="Static Semantics: ExportedNames"><span class="secnum">16.2.3.3</span> SS: ExportedNames</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-exportentries" title="Static Semantics: ExportEntries"><span class="secnum">16.2.3.4</span> SS: ExportEntries</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-exportentriesformodule" title="Static Semantics: ExportEntriesForModule"><span class="secnum">16.2.3.5</span> SS: ExportEntriesForModule</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-static-semantics-referencedbindings" title="Static Semantics: ReferencedBindings"><span class="secnum">16.2.3.6</span> SS: ReferencedBindings</a></li><li><span class="item-toggle-none"></span><a href="ecmascript-language-scripts-and-modules.html#sec-exports-runtime-semantics-evaluation" title="Runtime Semantics: Evaluation"><span class="secnum">16.2.3.7</span> RS: Evaluation</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="error-handling-and-language-extensions.html#sec-error-handling-and-language-extensions" title="Error Handling and Language Extensions"><span class="secnum">17</span> Error Handling and Language Extensions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="error-handling-and-language-extensions.html#sec-forbidden-extensions" title="Forbidden Extensions"><span class="secnum">17.1</span> Forbidden Extensions</a></li></ol></li><li><span class="item-toggle-none"></span><a href="ecmascript-standard-built-in-objects.html#sec-ecmascript-standard-built-in-objects" title="ECMAScript Standard Built-in Objects"><span class="secnum">18</span> ECMAScript Standard Built-in Objects</a></li><li><span class="item-toggle">+</span><a href="global-object.html#sec-global-object" title="The Global Object"><span class="secnum">19</span> The Global Object</a><ol class="toc"><li><span class="item-toggle">+</span><a href="global-object.html#sec-value-properties-of-the-global-object" title="Value Properties of the Global Object"><span class="secnum">19.1</span> Value Properties of the Global Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="global-object.html#sec-globalthis" title="globalThis"><span class="secnum">19.1.1</span> globalThis</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-value-properties-of-the-global-object-infinity" title="Infinity"><span class="secnum">19.1.2</span> Infinity</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-value-properties-of-the-global-object-nan" title="NaN"><span class="secnum">19.1.3</span> NaN</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-undefined" title="undefined"><span class="secnum">19.1.4</span> undefined</a></li></ol></li><li><span class="item-toggle">+</span><a href="global-object.html#sec-function-properties-of-the-global-object" title="Function Properties of the Global Object"><span class="secnum">19.2</span> Function Properties of the Global Object</a><ol class="toc"><li><span class="item-toggle">+</span><a href="global-object.html#sec-eval-x" title="eval ( x )"><span class="secnum">19.2.1</span> eval ( <var>x</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="global-object.html#sec-performeval" title="PerformEval ( x, strictCaller, direct )"><span class="secnum">19.2.1.1</span> PerformEval ( <var>x</var>, <var>strictCaller</var>, <var>direct</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-hostensurecancompilestrings" title="HostEnsureCanCompileStrings ( calleeRealm, parameterStrings, bodyString, direct )"><span class="secnum">19.2.1.2</span> HostEnsureCanCompileStrings ( <var>calleeRealm</var>, <var>parameterStrings</var>, <var>bodyString</var>, <var>direct</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-evaldeclarationinstantiation" title="EvalDeclarationInstantiation ( body, varEnv, lexEnv, privateEnv, strict )"><span class="secnum">19.2.1.3</span> EvalDeclarationInstantiation ( <var>body</var>, <var>varEnv</var>, <var>lexEnv</var>, <var>privateEnv</var>, <var>strict</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-isfinite-number" title="isFinite ( number )"><span class="secnum">19.2.2</span> isFinite ( <var>number</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-isnan-number" title="isNaN ( number )"><span class="secnum">19.2.3</span> isNaN ( <var>number</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-parsefloat-string" title="parseFloat ( string )"><span class="secnum">19.2.4</span> parseFloat ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-parseint-string-radix" title="parseInt ( string, radix )"><span class="secnum">19.2.5</span> parseInt ( <var>string</var>, <var>radix</var> )</a></li><li><span class="item-toggle">+</span><a href="global-object.html#sec-uri-handling-functions" title="URI Handling Functions"><span class="secnum">19.2.6</span> URI Handling Functions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="global-object.html#sec-decodeuri-encodeduri" title="decodeURI ( encodedURI )"><span class="secnum">19.2.6.1</span> decodeURI ( <var>encodedURI</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-decodeuricomponent-encodeduricomponent" title="decodeURIComponent ( encodedURIComponent )"><span class="secnum">19.2.6.2</span> decodeURIComponent ( <var>encodedURIComponent</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-encodeuri-uri" title="encodeURI ( uri )"><span class="secnum">19.2.6.3</span> encodeURI ( <var>uri</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-encodeuricomponent-uricomponent" title="encodeURIComponent ( uriComponent )"><span class="secnum">19.2.6.4</span> encodeURIComponent ( <var>uriComponent</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-encode" title="Encode ( string, extraUnescaped )"><span class="secnum">19.2.6.5</span> Encode ( <var>string</var>, <var>extraUnescaped</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-decode" title="Decode ( string, preserveEscapeSet )"><span class="secnum">19.2.6.6</span> Decode ( <var>string</var>, <var>preserveEscapeSet</var> )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-parsehexoctet" title="ParseHexOctet ( string, position )"><span class="secnum">19.2.6.7</span> ParseHexOctet ( <var>string</var>, <var>position</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="global-object.html#sec-constructor-properties-of-the-global-object" title="Constructor Properties of the Global Object"><span class="secnum">19.3</span> Constructor Properties of the Global Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-aggregate-error" title="AggregateError ( . . . )"><span class="secnum">19.3.1</span> AggregateError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-array" title="Array ( . . . )"><span class="secnum">19.3.2</span> Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-arraybuffer" title="ArrayBuffer ( . . . )"><span class="secnum">19.3.3</span> ArrayBuffer ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-bigint" title="BigInt ( . . . )"><span class="secnum">19.3.4</span> BigInt ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-bigint64array" title="BigInt64Array ( . . . )"><span class="secnum">19.3.5</span> BigInt64Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-biguint64array" title="BigUint64Array ( . . . )"><span class="secnum">19.3.6</span> BigUint64Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-boolean" title="Boolean ( . . . )"><span class="secnum">19.3.7</span> Boolean ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-dataview" title="DataView ( . . . )"><span class="secnum">19.3.8</span> DataView ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-date" title="Date ( . . . )"><span class="secnum">19.3.9</span> Date ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-error" title="Error ( . . . )"><span class="secnum">19.3.10</span> Error ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-evalerror" title="EvalError ( . . . )"><span class="secnum">19.3.11</span> EvalError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-finalization-registry" title="FinalizationRegistry ( . . . )"><span class="secnum">19.3.12</span> FinalizationRegistry ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-float16array" title="Float16Array ( . . . )"><span class="secnum">19.3.13</span> Float16Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-float32array" title="Float32Array ( . . . )"><span class="secnum">19.3.14</span> Float32Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-float64array" title="Float64Array ( . . . )"><span class="secnum">19.3.15</span> Float64Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-function" title="Function ( . . . )"><span class="secnum">19.3.16</span> Function ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-int8array" title="Int8Array ( . . . )"><span class="secnum">19.3.17</span> Int8Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-int16array" title="Int16Array ( . . . )"><span class="secnum">19.3.18</span> Int16Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-int32array" title="Int32Array ( . . . )"><span class="secnum">19.3.19</span> Int32Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-iterator" title="Iterator ( . . . )"><span class="secnum">19.3.20</span> Iterator ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-map" title="Map ( . . . )"><span class="secnum">19.3.21</span> Map ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-number" title="Number ( . . . )"><span class="secnum">19.3.22</span> Number ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-object" title="Object ( . . . )"><span class="secnum">19.3.23</span> Object ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-promise" title="Promise ( . . . )"><span class="secnum">19.3.24</span> Promise ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-proxy" title="Proxy ( . . . )"><span class="secnum">19.3.25</span> Proxy ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-rangeerror" title="RangeError ( . . . )"><span class="secnum">19.3.26</span> RangeError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-referenceerror" title="ReferenceError ( . . . )"><span class="secnum">19.3.27</span> ReferenceError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-regexp" title="RegExp ( . . . )"><span class="secnum">19.3.28</span> RegExp ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-set" title="Set ( . . . )"><span class="secnum">19.3.29</span> Set ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-sharedarraybuffer" title="SharedArrayBuffer ( . . . )"><span class="secnum">19.3.30</span> SharedArrayBuffer ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-string" title="String ( . . . )"><span class="secnum">19.3.31</span> String ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-symbol" title="Symbol ( . . . )"><span class="secnum">19.3.32</span> Symbol ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-syntaxerror" title="SyntaxError ( . . . )"><span class="secnum">19.3.33</span> SyntaxError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-typeerror" title="TypeError ( . . . )"><span class="secnum">19.3.34</span> TypeError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-uint8array" title="Uint8Array ( . . . )"><span class="secnum">19.3.35</span> Uint8Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-uint8clampedarray" title="Uint8ClampedArray ( . . . )"><span class="secnum">19.3.36</span> Uint8ClampedArray ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-uint16array" title="Uint16Array ( . . . )"><span class="secnum">19.3.37</span> Uint16Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-uint32array" title="Uint32Array ( . . . )"><span class="secnum">19.3.38</span> Uint32Array ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-urierror" title="URIError ( . . . )"><span class="secnum">19.3.39</span> URIError ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-weakmap" title="WeakMap ( . . . )"><span class="secnum">19.3.40</span> WeakMap ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-weakref" title="WeakRef ( . . . )"><span class="secnum">19.3.41</span> WeakRef ( . . . )</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-constructor-properties-of-the-global-object-weakset" title="WeakSet ( . . . )"><span class="secnum">19.3.42</span> WeakSet ( . . . )</a></li></ol></li><li><span class="item-toggle">+</span><a href="global-object.html#sec-other-properties-of-the-global-object" title="Other Properties of the Global Object"><span class="secnum">19.4</span> Other Properties of the Global Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="global-object.html#sec-atomics" title="Atomics"><span class="secnum">19.4.1</span> Atomics</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-json" title="JSON"><span class="secnum">19.4.2</span> JSON</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-math" title="Math"><span class="secnum">19.4.3</span> Math</a></li><li><span class="item-toggle-none"></span><a href="global-object.html#sec-reflect" title="Reflect"><span class="secnum">19.4.4</span> Reflect</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-fundamental-objects" title="Fundamental Objects"><span class="secnum">20</span> Fundamental Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-object-objects" title="Object Objects"><span class="secnum">20.1</span> Object Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-object-constructor" title="The Object Constructor"><span class="secnum">20.1.1</span> The Object Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object-value" title="Object ( value )"><span class="secnum">20.1.1.1</span> Object ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-object-constructor" title="Properties of the Object Constructor"><span class="secnum">20.1.2</span> Properties of the Object Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.assign" title="Object.assign ( target, ...sources )"><span class="secnum">20.1.2.1</span> Object.assign ( <var>target</var>, ...<var>sources</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.create" title="Object.create ( O, Properties )"><span class="secnum">20.1.2.2</span> Object.create ( <var>O</var>, <var>Properties</var> )</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-object.defineproperties" title="Object.defineProperties ( O, Properties )"><span class="secnum">20.1.2.3</span> Object.defineProperties ( <var>O</var>, <var>Properties</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-objectdefineproperties" title="ObjectDefineProperties ( O, Properties )"><span class="secnum">20.1.2.3.1</span> ObjectDefineProperties ( <var>O</var>, <var>Properties</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.defineproperty" title="Object.defineProperty ( O, P, Attributes )"><span class="secnum">20.1.2.4</span> Object.defineProperty ( <var>O</var>, <var>P</var>, <var>Attributes</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.entries" title="Object.entries ( O )"><span class="secnum">20.1.2.5</span> Object.entries ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.freeze" title="Object.freeze ( O )"><span class="secnum">20.1.2.6</span> Object.freeze ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.fromentries" title="Object.fromEntries ( iterable )"><span class="secnum">20.1.2.7</span> Object.fromEntries ( <var>iterable</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.getownpropertydescriptor" title="Object.getOwnPropertyDescriptor ( O, P )"><span class="secnum">20.1.2.8</span> Object.getOwnPropertyDescriptor ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.getownpropertydescriptors" title="Object.getOwnPropertyDescriptors ( O )"><span class="secnum">20.1.2.9</span> Object.getOwnPropertyDescriptors ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.getownpropertynames" title="Object.getOwnPropertyNames ( O )"><span class="secnum">20.1.2.10</span> Object.getOwnPropertyNames ( <var>O</var> )</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-object.getownpropertysymbols" title="Object.getOwnPropertySymbols ( O )"><span class="secnum">20.1.2.11</span> Object.getOwnPropertySymbols ( <var>O</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-getownpropertykeys" title="GetOwnPropertyKeys ( O, type )"><span class="secnum">20.1.2.11.1</span> GetOwnPropertyKeys ( <var>O</var>, <var>type</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.getprototypeof" title="Object.getPrototypeOf ( O )"><span class="secnum">20.1.2.12</span> Object.getPrototypeOf ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.groupby" title="Object.groupBy ( items, callback )"><span class="secnum">20.1.2.13</span> Object.groupBy ( <var>items</var>, <var>callback</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.hasown" title="Object.hasOwn ( O, P )"><span class="secnum">20.1.2.14</span> Object.hasOwn ( <var>O</var>, <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.is" title="Object.is ( value1, value2 )"><span class="secnum">20.1.2.15</span> Object.is ( <var>value1</var>, <var>value2</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.isextensible" title="Object.isExtensible ( O )"><span class="secnum">20.1.2.16</span> Object.isExtensible ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.isfrozen" title="Object.isFrozen ( O )"><span class="secnum">20.1.2.17</span> Object.isFrozen ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.issealed" title="Object.isSealed ( O )"><span class="secnum">20.1.2.18</span> Object.isSealed ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.keys" title="Object.keys ( O )"><span class="secnum">20.1.2.19</span> Object.keys ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.preventextensions" title="Object.preventExtensions ( O )"><span class="secnum">20.1.2.20</span> Object.preventExtensions ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype" title="Object.prototype"><span class="secnum">20.1.2.21</span> Object.prototype</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.seal" title="Object.seal ( O )"><span class="secnum">20.1.2.22</span> Object.seal ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.setprototypeof" title="Object.setPrototypeOf ( O, proto )"><span class="secnum">20.1.2.23</span> Object.setPrototypeOf ( <var>O</var>, <var>proto</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.values" title="Object.values ( O )"><span class="secnum">20.1.2.24</span> Object.values ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object" title="Properties of the Object Prototype Object"><span class="secnum">20.1.3</span> Properties of the Object Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.constructor" title="Object.prototype.constructor"><span class="secnum">20.1.3.1</span> Object.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.hasownproperty" title="Object.prototype.hasOwnProperty ( V )"><span class="secnum">20.1.3.2</span> Object.prototype.hasOwnProperty ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.isprototypeof" title="Object.prototype.isPrototypeOf ( V )"><span class="secnum">20.1.3.3</span> Object.prototype.isPrototypeOf ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.propertyisenumerable" title="Object.prototype.propertyIsEnumerable ( V )"><span class="secnum">20.1.3.4</span> Object.prototype.propertyIsEnumerable ( <var>V</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.tolocalestring" title="Object.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">20.1.3.5</span> Object.prototype.toLocaleString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.tostring" title="Object.prototype.toString ( )"><span class="secnum">20.1.3.6</span> Object.prototype.toString ( )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.valueof" title="Object.prototype.valueOf ( )"><span class="secnum">20.1.3.7</span> Object.prototype.valueOf ( )</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-object.prototype.__proto__" title="Object.prototype.__proto__"><span class="secnum">20.1.3.8</span> Object.prototype.__proto__</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-get-object.prototype.__proto__" title="get Object.prototype.__proto__"><span class="secnum">20.1.3.8.1</span> get Object.prototype.__proto__</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-set-object.prototype.__proto__" title="set Object.prototype.__proto__"><span class="secnum">20.1.3.8.2</span> set Object.prototype.__proto__</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-object.prototype-legacy-accessor-methods" title="Legacy Object.prototype Accessor Methods"><span class="secnum">20.1.3.9</span> Legacy Object.prototype Accessor Methods</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.__defineGetter__" title="Object.prototype.__defineGetter__ ( P, getter )"><span class="secnum">20.1.3.9.1</span> Object.prototype.__defineGetter__ ( <var>P</var>, <var>getter</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.__defineSetter__" title="Object.prototype.__defineSetter__ ( P, setter )"><span class="secnum">20.1.3.9.2</span> Object.prototype.__defineSetter__ ( <var>P</var>, <var>setter</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.__lookupGetter__" title="Object.prototype.__lookupGetter__ ( P )"><span class="secnum">20.1.3.9.3</span> Object.prototype.__lookupGetter__ ( <var>P</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-object.prototype.__lookupSetter__" title="Object.prototype.__lookupSetter__ ( P )"><span class="secnum">20.1.3.9.4</span> Object.prototype.__lookupSetter__ ( <var>P</var> )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-properties-of-object-instances" title="Properties of Object Instances"><span class="secnum">20.1.4</span> Properties of Object Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-function-objects" title="Function Objects"><span class="secnum">20.2</span> Function Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-function-constructor" title="The Function Constructor"><span class="secnum">20.2.1</span> The Function Constructor</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-function-p1-p2-pn-body" title="Function ( ...parameterArgs, bodyArg )"><span class="secnum">20.2.1.1</span> Function ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-createdynamicfunction" title="CreateDynamicFunction ( constructor, newTarget, kind, parameterArgs, bodyArg )"><span class="secnum">20.2.1.1.1</span> CreateDynamicFunction ( <var>constructor</var>, <var>newTarget</var>, <var>kind</var>, <var>parameterArgs</var>, <var>bodyArg</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-function-constructor" title="Properties of the Function Constructor"><span class="secnum">20.2.2</span> Properties of the Function Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function.prototype" title="Function.prototype"><span class="secnum">20.2.2.1</span> Function.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-function-prototype-object" title="Properties of the Function Prototype Object"><span class="secnum">20.2.3</span> Properties of the Function Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function.prototype.apply" title="Function.prototype.apply ( thisArg, argArray )"><span class="secnum">20.2.3.1</span> Function.prototype.apply ( <var>thisArg</var>, <var>argArray</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function.prototype.bind" title="Function.prototype.bind ( thisArg, ...args )"><span class="secnum">20.2.3.2</span> Function.prototype.bind ( <var>thisArg</var>, ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a 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class="item-toggle">+</span><a href="fundamental-objects.html#sec-function-instances" title="Function Instances"><span class="secnum">20.2.4</span> Function Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function-instances-length" title="length"><span class="secnum">20.2.4.1</span> length</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function-instances-name" title="name"><span class="secnum">20.2.4.2</span> name</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function-instances-prototype" title="prototype"><span class="secnum">20.2.4.3</span> prototype</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-hosthassourcetextavailable" title="HostHasSourceTextAvailable ( func )"><span class="secnum">20.2.5</span> HostHasSourceTextAvailable ( <var>func</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-boolean-objects" title="Boolean Objects"><span class="secnum">20.3</span> Boolean Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-boolean-constructor" title="The Boolean Constructor"><span class="secnum">20.3.1</span> The Boolean Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-boolean-constructor-boolean-value" title="Boolean ( value )"><span class="secnum">20.3.1.1</span> Boolean ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-boolean-constructor" title="Properties of the Boolean Constructor"><span class="secnum">20.3.2</span> Properties of the Boolean Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-boolean.prototype" title="Boolean.prototype"><span class="secnum">20.3.2.1</span> Boolean.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-boolean-prototype-object" title="Properties of the Boolean Prototype Object"><span class="secnum">20.3.3</span> Properties of the Boolean Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-boolean.prototype.constructor" title="Boolean.prototype.constructor"><span class="secnum">20.3.3.1</span> Boolean.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-boolean.prototype.tostring" title="Boolean.prototype.toString ( )"><span class="secnum">20.3.3.2</span> Boolean.prototype.toString ( )</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-boolean.prototype.valueof" title="Boolean.prototype.valueOf ( )"><span class="secnum">20.3.3.3</span> Boolean.prototype.valueOf ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-thisbooleanvalue" title="ThisBooleanValue ( value )"><span class="secnum">20.3.3.3.1</span> ThisBooleanValue ( <var>value</var> )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-properties-of-boolean-instances" title="Properties of Boolean Instances"><span class="secnum">20.3.4</span> Properties of Boolean Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-symbol-objects" title="Symbol Objects"><span class="secnum">20.4</span> Symbol Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-symbol-constructor" title="The Symbol Constructor"><span class="secnum">20.4.1</span> The Symbol Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol-description" title="Symbol ( [ description ] )"><span class="secnum">20.4.1.1</span> Symbol ( [ <var>description</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-symbol-constructor" title="Properties of the Symbol Constructor"><span class="secnum">20.4.2</span> Properties of the Symbol Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.asynciterator" title="Symbol.asyncIterator"><span class="secnum">20.4.2.1</span> Symbol.asyncIterator</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.for" title="Symbol.for ( key )"><span class="secnum">20.4.2.2</span> Symbol.for ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.hasinstance" title="Symbol.hasInstance"><span class="secnum">20.4.2.3</span> Symbol.hasInstance</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.isconcatspreadable" title="Symbol.isConcatSpreadable"><span class="secnum">20.4.2.4</span> Symbol.isConcatSpreadable</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.iterator" title="Symbol.iterator"><span class="secnum">20.4.2.5</span> Symbol.iterator</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.keyfor" title="Symbol.keyFor ( sym )"><span class="secnum">20.4.2.6</span> Symbol.keyFor ( <var>sym</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.match" title="Symbol.match"><span class="secnum">20.4.2.7</span> Symbol.match</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.matchall" title="Symbol.matchAll"><span class="secnum">20.4.2.8</span> Symbol.matchAll</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.prototype" title="Symbol.prototype"><span class="secnum">20.4.2.9</span> Symbol.prototype</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.replace" title="Symbol.replace"><span class="secnum">20.4.2.10</span> Symbol.replace</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.search" title="Symbol.search"><span class="secnum">20.4.2.11</span> Symbol.search</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.species" title="Symbol.species"><span class="secnum">20.4.2.12</span> Symbol.species</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.split" title="Symbol.split"><span class="secnum">20.4.2.13</span> Symbol.split</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.toprimitive" title="Symbol.toPrimitive"><span class="secnum">20.4.2.14</span> Symbol.toPrimitive</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.tostringtag" title="Symbol.toStringTag"><span class="secnum">20.4.2.15</span> Symbol.toStringTag</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.unscopables" title="Symbol.unscopables"><span class="secnum">20.4.2.16</span> Symbol.unscopables</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-symbol-prototype-object" title="Properties of the Symbol Prototype Object"><span class="secnum">20.4.3</span> Properties of the Symbol Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.prototype.constructor" title="Symbol.prototype.constructor"><span class="secnum">20.4.3.1</span> Symbol.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.prototype.description" title="get Symbol.prototype.description"><span class="secnum">20.4.3.2</span> get Symbol.prototype.description</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-symbol.prototype.tostring" title="Symbol.prototype.toString ( )"><span class="secnum">20.4.3.3</span> Symbol.prototype.toString ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symboldescriptivestring" title="SymbolDescriptiveString ( sym )"><span class="secnum">20.4.3.3.1</span> SymbolDescriptiveString ( <var>sym</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-symbol.prototype.valueof" title="Symbol.prototype.valueOf ( )"><span class="secnum">20.4.3.4</span> Symbol.prototype.valueOf ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-thissymbolvalue" title="ThisSymbolValue ( value )"><span class="secnum">20.4.3.4.1</span> ThisSymbolValue ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.prototype-%symbol.toprimitive%" title="Symbol.prototype [ %Symbol.toPrimitive% ] ( hint )"><span class="secnum">20.4.3.5</span> Symbol.prototype [ %Symbol.toPrimitive% ] ( <var>hint</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-symbol.prototype-%symbol.tostringtag%" title="Symbol.prototype [ %Symbol.toStringTag% ]"><span class="secnum">20.4.3.6</span> Symbol.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-properties-of-symbol-instances" title="Properties of Symbol Instances"><span class="secnum">20.4.4</span> Properties of Symbol Instances</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-abstract-operations-for-symbols" title="Abstract Operations for Symbols"><span class="secnum">20.4.5</span> Abstract Operations for Symbols</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-keyforsymbol" title="KeyForSymbol ( sym )"><span class="secnum">20.4.5.1</span> KeyForSymbol ( <var>sym</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-error-objects" title="Error Objects"><span class="secnum">20.5</span> Error Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-error-constructor" title="The Error Constructor"><span class="secnum">20.5.1</span> The Error Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-error-message" title="Error ( message [ , options ] )"><span class="secnum">20.5.1.1</span> Error ( <var>message</var> [ , <var>options</var> ] )</a></li></ol></li><li><span 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href="fundamental-objects.html#sec-error.prototype.constructor" title="Error.prototype.constructor"><span class="secnum">20.5.3.1</span> Error.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-error.prototype.message" title="Error.prototype.message"><span class="secnum">20.5.3.2</span> Error.prototype.message</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-error.prototype.name" title="Error.prototype.name"><span class="secnum">20.5.3.3</span> Error.prototype.name</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-error.prototype.tostring" title="Error.prototype.toString ( )"><span class="secnum">20.5.3.4</span> Error.prototype.toString ( )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-properties-of-error-instances" title="Properties of Error Instances"><span class="secnum">20.5.4</span> Properties of 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AggregateError Constructor"><span class="secnum">20.5.7.2</span> Properties of the AggregateError Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-aggregate-error.prototype" title="AggregateError.prototype"><span class="secnum">20.5.7.2.1</span> AggregateError.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-aggregate-error-prototype-objects" title="Properties of the AggregateError Prototype Object"><span class="secnum">20.5.7.3</span> Properties of the AggregateError Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-aggregate-error.prototype.constructor" title="AggregateError.prototype.constructor"><span class="secnum">20.5.7.3.1</span> AggregateError.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-aggregate-error.prototype.message" title="AggregateError.prototype.message"><span class="secnum">20.5.7.3.2</span> AggregateError.prototype.message</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-aggregate-error.prototype.name" title="AggregateError.prototype.name"><span class="secnum">20.5.7.3.3</span> AggregateError.prototype.name</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-properties-of-aggregate-error-instances" title="Properties of AggregateError Instances"><span class="secnum">20.5.7.4</span> Properties of AggregateError Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-abstract-operations-for-error-objects" title="Abstract Operations for Error Objects"><span class="secnum">20.5.8</span> Abstract Operations for Error Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-installerrorcause" title="InstallErrorCause ( O, options )"><span class="secnum">20.5.8.1</span> InstallErrorCause ( <var>O</var>, <var>options</var> )</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-numbers-and-dates" title="Numbers and Dates"><span class="secnum">21</span> Numbers and Dates</a><ol class="toc"><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-number-objects" title="Number Objects"><span class="secnum">21.1</span> Number Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-number-constructor" title="The Number Constructor"><span class="secnum">21.1.1</span> The Number Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number-constructor-number-value" title="Number ( value )"><span class="secnum">21.1.1.1</span> Number ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-properties-of-the-number-constructor" title="Properties of the Number Constructor"><span class="secnum">21.1.2</span> Properties of the Number Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.epsilon" title="Number.EPSILON"><span class="secnum">21.1.2.1</span> Number.EPSILON</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.isfinite" title="Number.isFinite ( number )"><span class="secnum">21.1.2.2</span> Number.isFinite ( <var>number</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.isinteger" title="Number.isInteger ( number )"><span class="secnum">21.1.2.3</span> Number.isInteger ( <var>number</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.isnan" title="Number.isNaN ( number )"><span class="secnum">21.1.2.4</span> Number.isNaN ( <var>number</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.issafeinteger" title="Number.isSafeInteger ( number )"><span class="secnum">21.1.2.5</span> Number.isSafeInteger ( <var>number</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.max_safe_integer" title="Number.MAX_SAFE_INTEGER"><span class="secnum">21.1.2.6</span> Number.MAX_SAFE_INTEGER</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.max_value" title="Number.MAX_VALUE"><span class="secnum">21.1.2.7</span> Number.MAX_VALUE</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.min_safe_integer" title="Number.MIN_SAFE_INTEGER"><span class="secnum">21.1.2.8</span> Number.MIN_SAFE_INTEGER</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.min_value" title="Number.MIN_VALUE"><span class="secnum">21.1.2.9</span> Number.MIN_VALUE</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.nan" title="Number.NaN"><span class="secnum">21.1.2.10</span> Number.NaN</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.negative_infinity" title="Number.NEGATIVE_INFINITY"><span class="secnum">21.1.2.11</span> Number.NEGATIVE_INFINITY</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.parsefloat" title="Number.parseFloat ( string )"><span class="secnum">21.1.2.12</span> Number.parseFloat ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.parseint" title="Number.parseInt ( string, radix )"><span class="secnum">21.1.2.13</span> Number.parseInt ( <var>string</var>, <var>radix</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.positive_infinity" title="Number.POSITIVE_INFINITY"><span class="secnum">21.1.2.14</span> Number.POSITIVE_INFINITY</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype" title="Number.prototype"><span class="secnum">21.1.2.15</span> Number.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-properties-of-the-number-prototype-object" title="Properties of the Number Prototype Object"><span class="secnum">21.1.3</span> Properties of the Number Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype.constructor" title="Number.prototype.constructor"><span class="secnum">21.1.3.1</span> Number.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype.toexponential" title="Number.prototype.toExponential ( fractionDigits )"><span class="secnum">21.1.3.2</span> Number.prototype.toExponential ( <var>fractionDigits</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype.tofixed" title="Number.prototype.toFixed ( fractionDigits )"><span class="secnum">21.1.3.3</span> Number.prototype.toFixed ( <var>fractionDigits</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype.tolocalestring" title="Number.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">21.1.3.4</span> Number.prototype.toLocaleString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype.toprecision" title="Number.prototype.toPrecision ( precision )"><span class="secnum">21.1.3.5</span> Number.prototype.toPrecision ( <var>precision</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-number.prototype.tostring" title="Number.prototype.toString ( [ radix ] )"><span class="secnum">21.1.3.6</span> Number.prototype.toString ( [ <var>radix</var> ] )</a></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-number.prototype.valueof" title="Number.prototype.valueOf ( )"><span class="secnum">21.1.3.7</span> Number.prototype.valueOf ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-thisnumbervalue" title="ThisNumberValue ( value )"><span class="secnum">21.1.3.7.1</span> ThisNumberValue ( <var>value</var> )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-properties-of-number-instances" title="Properties of Number Instances"><span class="secnum">21.1.4</span> Properties of Number Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-bigint-objects" title="BigInt Objects"><span class="secnum">21.2</span> BigInt Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-bigint-constructor" title="The BigInt Constructor"><span class="secnum">21.2.1</span> The BigInt Constructor</a><ol class="toc"><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-bigint-constructor-number-value" title="BigInt ( value )"><span class="secnum">21.2.1.1</span> BigInt ( <var>value</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-numbertobigint" title="NumberToBigInt ( number )"><span class="secnum">21.2.1.1.1</span> NumberToBigInt ( <var>number</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-properties-of-the-bigint-constructor" title="Properties of the BigInt Constructor"><span class="secnum">21.2.2</span> Properties of the BigInt Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.asintn" title="BigInt.asIntN ( bits, bigint )"><span class="secnum">21.2.2.1</span> BigInt.asIntN ( <var>bits</var>, <var>bigint</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.asuintn" title="BigInt.asUintN ( bits, bigint )"><span class="secnum">21.2.2.2</span> BigInt.asUintN ( <var>bits</var>, <var>bigint</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.prototype" title="BigInt.prototype"><span class="secnum">21.2.2.3</span> BigInt.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-properties-of-the-bigint-prototype-object" title="Properties of the BigInt Prototype Object"><span class="secnum">21.2.3</span> Properties of the BigInt Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.prototype.constructor" title="BigInt.prototype.constructor"><span class="secnum">21.2.3.1</span> BigInt.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.prototype.tolocalestring" title="BigInt.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">21.2.3.2</span> BigInt.prototype.toLocaleString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.prototype.tostring" title="BigInt.prototype.toString ( [ radix ] )"><span class="secnum">21.2.3.3</span> BigInt.prototype.toString ( [ <var>radix</var> ] )</a></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-bigint.prototype.valueof" title="BigInt.prototype.valueOf ( )"><span class="secnum">21.2.3.4</span> BigInt.prototype.valueOf ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-thisbigintvalue" title="ThisBigIntValue ( value )"><span class="secnum">21.2.3.4.1</span> ThisBigIntValue ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-bigint.prototype-%symbol.tostringtag%" title="BigInt.prototype [ %Symbol.toStringTag% ]"><span class="secnum">21.2.3.5</span> BigInt.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-properties-of-bigint-instances" title="Properties of BigInt Instances"><span class="secnum">21.2.4</span> Properties of BigInt Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-math-object" title="The Math Object"><span class="secnum">21.3</span> The Math Object</a><ol class="toc"><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-value-properties-of-the-math-object" title="Value Properties of the Math Object"><span class="secnum">21.3.1</span> Value Properties of the Math Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.e" title="Math.E"><span class="secnum">21.3.1.1</span> Math.E</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.ln10" title="Math.LN10"><span class="secnum">21.3.1.2</span> Math.LN10</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.ln2" title="Math.LN2"><span class="secnum">21.3.1.3</span> Math.LN2</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.log10e" title="Math.LOG10E"><span class="secnum">21.3.1.4</span> Math.LOG10E</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.log2e" title="Math.LOG2E"><span class="secnum">21.3.1.5</span> Math.LOG2E</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.pi" title="Math.PI"><span class="secnum">21.3.1.6</span> Math.PI</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sqrt1_2" title="Math.SQRT1_2"><span class="secnum">21.3.1.7</span> Math.SQRT1_2</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sqrt2" title="Math.SQRT2"><span class="secnum">21.3.1.8</span> Math.SQRT2</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math-%symbol.tostringtag%" title="Math [ %Symbol.toStringTag% ]"><span class="secnum">21.3.1.9</span> Math [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-function-properties-of-the-math-object" title="Function Properties of the Math Object"><span class="secnum">21.3.2</span> Function Properties of the Math Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.abs" title="Math.abs ( x )"><span class="secnum">21.3.2.1</span> Math.abs ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.acos" title="Math.acos ( x )"><span class="secnum">21.3.2.2</span> Math.acos ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.acosh" title="Math.acosh ( x )"><span class="secnum">21.3.2.3</span> Math.acosh ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.asin" title="Math.asin ( x )"><span class="secnum">21.3.2.4</span> Math.asin ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.asinh" title="Math.asinh ( x )"><span class="secnum">21.3.2.5</span> Math.asinh ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.atan" title="Math.atan ( x )"><span class="secnum">21.3.2.6</span> Math.atan ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.atanh" title="Math.atanh ( x )"><span class="secnum">21.3.2.7</span> Math.atanh ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.atan2" title="Math.atan2 ( y, x )"><span class="secnum">21.3.2.8</span> Math.atan2 ( <var>y</var>, <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.cbrt" title="Math.cbrt ( x )"><span class="secnum">21.3.2.9</span> Math.cbrt ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.ceil" title="Math.ceil ( x )"><span class="secnum">21.3.2.10</span> Math.ceil ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.clz32" title="Math.clz32 ( x )"><span class="secnum">21.3.2.11</span> Math.clz32 ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.cos" title="Math.cos ( x )"><span class="secnum">21.3.2.12</span> Math.cos ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.cosh" title="Math.cosh ( x )"><span class="secnum">21.3.2.13</span> Math.cosh ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.exp" title="Math.exp ( x )"><span class="secnum">21.3.2.14</span> Math.exp ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.expm1" title="Math.expm1 ( x )"><span class="secnum">21.3.2.15</span> Math.expm1 ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.floor" title="Math.floor ( x )"><span class="secnum">21.3.2.16</span> Math.floor ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.fround" title="Math.fround ( x )"><span class="secnum">21.3.2.17</span> Math.fround ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.f16round" title="Math.f16round ( x )"><span class="secnum">21.3.2.18</span> Math.f16round ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.hypot" title="Math.hypot ( ...args )"><span class="secnum">21.3.2.19</span> Math.hypot ( ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.imul" title="Math.imul ( x, y )"><span class="secnum">21.3.2.20</span> Math.imul ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.log" title="Math.log ( x )"><span class="secnum">21.3.2.21</span> Math.log ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.log1p" title="Math.log1p ( x )"><span class="secnum">21.3.2.22</span> Math.log1p ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.log10" title="Math.log10 ( x )"><span class="secnum">21.3.2.23</span> Math.log10 ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.log2" title="Math.log2 ( x )"><span class="secnum">21.3.2.24</span> Math.log2 ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.max" title="Math.max ( ...args )"><span class="secnum">21.3.2.25</span> Math.max ( ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.min" title="Math.min ( ...args )"><span class="secnum">21.3.2.26</span> Math.min ( ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.pow" title="Math.pow ( base, exponent )"><span class="secnum">21.3.2.27</span> Math.pow ( <var>base</var>, <var>exponent</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.random" title="Math.random ( )"><span class="secnum">21.3.2.28</span> Math.random ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.round" title="Math.round ( x )"><span class="secnum">21.3.2.29</span> Math.round ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sign" title="Math.sign ( x )"><span class="secnum">21.3.2.30</span> Math.sign ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sin" title="Math.sin ( x )"><span class="secnum">21.3.2.31</span> Math.sin ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sinh" title="Math.sinh ( x )"><span class="secnum">21.3.2.32</span> Math.sinh ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sqrt" title="Math.sqrt ( x )"><span class="secnum">21.3.2.33</span> Math.sqrt ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.sumprecise" title="Math.sumPrecise ( items )"><span class="secnum">21.3.2.34</span> Math.sumPrecise ( <var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.tan" title="Math.tan ( x )"><span class="secnum">21.3.2.35</span> Math.tan ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.tanh" title="Math.tanh ( x )"><span class="secnum">21.3.2.36</span> Math.tanh ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-math.trunc" title="Math.trunc ( x )"><span class="secnum">21.3.2.37</span> Math.trunc ( <var>x</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-date-objects" title="Date Objects"><span class="secnum">21.4</span> Date Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-overview-of-date-objects-and-definitions-of-abstract-operations" title="Overview of Date Objects and Definitions of Abstract Operations"><span class="secnum">21.4.1</span> Overview of Date Objects and Definitions of Abstract Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-time-values-and-time-range" title="Time Values and Time Range"><span class="secnum">21.4.1.1</span> Time Values and Time Range</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-time-related-constants" title="Time-related Constants"><span class="secnum">21.4.1.2</span> Time-related Constants</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-day" title="Day ( t )"><span class="secnum">21.4.1.3</span> Day ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-timewithinday" title="TimeWithinDay ( t )"><span class="secnum">21.4.1.4</span> TimeWithinDay ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-daysinyear" title="DaysInYear ( y )"><span class="secnum">21.4.1.5</span> DaysInYear ( <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-dayfromyear" title="DayFromYear ( y )"><span class="secnum">21.4.1.6</span> DayFromYear ( <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-timefromyear" title="TimeFromYear ( y )"><span class="secnum">21.4.1.7</span> TimeFromYear ( <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-yearfromtime" title="YearFromTime ( t )"><span class="secnum">21.4.1.8</span> YearFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-daywithinyear" title="DayWithinYear ( t )"><span class="secnum">21.4.1.9</span> DayWithinYear ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-inleapyear" title="InLeapYear ( t )"><span class="secnum">21.4.1.10</span> InLeapYear ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-monthfromtime" title="MonthFromTime ( t )"><span class="secnum">21.4.1.11</span> MonthFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-datefromtime" title="DateFromTime ( t )"><span class="secnum">21.4.1.12</span> DateFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-weekday" title="WeekDay ( t )"><span class="secnum">21.4.1.13</span> WeekDay ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-hourfromtime" title="HourFromTime ( t )"><span class="secnum">21.4.1.14</span> HourFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-minfromtime" title="MinFromTime ( t )"><span class="secnum">21.4.1.15</span> MinFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-secfromtime" title="SecFromTime ( t )"><span class="secnum">21.4.1.16</span> SecFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-msfromtime" title="msFromTime ( t )"><span class="secnum">21.4.1.17</span> msFromTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-getutcepochnanoseconds" title="GetUTCEpochNanoseconds ( year, month, day, hour, minute, second, millisecond, microsecond, nanosecond )"><span class="secnum">21.4.1.18</span> GetUTCEpochNanoseconds ( <var>year</var>, <var>month</var>, <var>day</var>, <var>hour</var>, <var>minute</var>, <var>second</var>, <var>millisecond</var>, <var>microsecond</var>, <var>nanosecond</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-time-zone-identifiers" title="Time Zone Identifiers"><span class="secnum">21.4.1.19</span> Time Zone Identifiers</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-getnamedtimezoneepochnanoseconds" title="GetNamedTimeZoneEpochNanoseconds ( timeZoneIdentifier, year, month, day, hour, minute, second, millisecond, microsecond, nanosecond )"><span class="secnum">21.4.1.20</span> GetNamedTimeZoneEpochNanoseconds ( <var>timeZoneIdentifier</var>, <var>year</var>, <var>month</var>, <var>day</var>, <var>hour</var>, <var>minute</var>, <var>second</var>, <var>millisecond</var>, <var>microsecond</var>, <var>nanosecond</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-getnamedtimezoneoffsetnanoseconds" title="GetNamedTimeZoneOffsetNanoseconds ( timeZoneIdentifier, epochNanoseconds )"><span class="secnum">21.4.1.21</span> GetNamedTimeZoneOffsetNanoseconds ( <var>timeZoneIdentifier</var>, <var>epochNanoseconds</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-time-zone-identifier-record" title="Time Zone Identifier Record"><span class="secnum">21.4.1.22</span> Time Zone Identifier Record</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-availablenamedtimezoneidentifiers" title="AvailableNamedTimeZoneIdentifiers ( )"><span class="secnum">21.4.1.23</span> AvailableNamedTimeZoneIdentifiers ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-systemtimezoneidentifier" title="SystemTimeZoneIdentifier ( )"><span class="secnum">21.4.1.24</span> SystemTimeZoneIdentifier ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-localtime" title="LocalTime ( t )"><span class="secnum">21.4.1.25</span> LocalTime ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-utc-t" title="UTC ( t )"><span class="secnum">21.4.1.26</span> UTC ( <var>t</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-maketime" title="MakeTime ( hour, min, sec, ms )"><span class="secnum">21.4.1.27</span> MakeTime ( <var>hour</var>, <var>min</var>, <var>sec</var>, <var>ms</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-makeday" title="MakeDay ( year, month, date )"><span class="secnum">21.4.1.28</span> MakeDay ( <var>year</var>, <var>month</var>, <var>date</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-makedate" title="MakeDate ( day, time )"><span class="secnum">21.4.1.29</span> MakeDate ( <var>day</var>, <var>time</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-makefullyear" title="MakeFullYear ( year )"><span class="secnum">21.4.1.30</span> MakeFullYear ( <var>year</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-timeclip" title="TimeClip ( time )"><span class="secnum">21.4.1.31</span> TimeClip ( <var>time</var> )</a></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-date-time-string-format" title="Date Time String Format"><span class="secnum">21.4.1.32</span> Date Time String Format</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-expanded-years" title="Expanded Years"><span class="secnum">21.4.1.32.1</span> Expanded Years</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-time-zone-offset-strings" title="Time Zone Offset String Format"><span class="secnum">21.4.1.33</span> Time Zone Offset String Format</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-istimezoneoffsetstring" title="IsTimeZoneOffsetString ( offsetString )"><span class="secnum">21.4.1.33.1</span> IsTimeZoneOffsetString ( <var>offsetString</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-parsetimezoneoffsetstring" title="ParseTimeZoneOffsetString ( offsetString )"><span class="secnum">21.4.1.33.2</span> ParseTimeZoneOffsetString ( <var>offsetString</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-date-constructor" title="The Date Constructor"><span class="secnum">21.4.2</span> The Date Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date" title="Date ( ...values )"><span class="secnum">21.4.2.1</span> Date ( ...<var>values</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-properties-of-the-date-constructor" title="Properties of the Date Constructor"><span class="secnum">21.4.3</span> Properties of the Date Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.now" title="Date.now ( )"><span class="secnum">21.4.3.1</span> Date.now ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.parse" title="Date.parse ( string )"><span class="secnum">21.4.3.2</span> Date.parse ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype" title="Date.prototype"><span class="secnum">21.4.3.3</span> Date.prototype</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.utc" title="Date.UTC ( year [ , month [ , date [ , hours [ , minutes [ , seconds [ , ms ] ] ] ] ] ] )"><span class="secnum">21.4.3.4</span> Date.UTC ( <var>year</var> [ , <var>month</var> [ , <var>date</var> [ , <var>hours</var> [ , <var>minutes</var> [ , <var>seconds</var> [ , <var>ms</var> ] ] ] ] ] ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-properties-of-the-date-prototype-object" title="Properties of the Date Prototype Object"><span class="secnum">21.4.4</span> Properties of the Date Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.constructor" title="Date.prototype.constructor"><span class="secnum">21.4.4.1</span> Date.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getdate" title="Date.prototype.getDate ( )"><span class="secnum">21.4.4.2</span> Date.prototype.getDate ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getday" title="Date.prototype.getDay ( )"><span class="secnum">21.4.4.3</span> Date.prototype.getDay ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getfullyear" title="Date.prototype.getFullYear ( )"><span class="secnum">21.4.4.4</span> Date.prototype.getFullYear ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.gethours" title="Date.prototype.getHours ( )"><span class="secnum">21.4.4.5</span> Date.prototype.getHours ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getmilliseconds" title="Date.prototype.getMilliseconds ( )"><span class="secnum">21.4.4.6</span> Date.prototype.getMilliseconds ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getminutes" title="Date.prototype.getMinutes ( )"><span class="secnum">21.4.4.7</span> Date.prototype.getMinutes ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getmonth" title="Date.prototype.getMonth ( )"><span class="secnum">21.4.4.8</span> Date.prototype.getMonth ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getseconds" title="Date.prototype.getSeconds ( )"><span class="secnum">21.4.4.9</span> Date.prototype.getSeconds ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.gettime" title="Date.prototype.getTime ( )"><span class="secnum">21.4.4.10</span> Date.prototype.getTime ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.gettimezoneoffset" title="Date.prototype.getTimezoneOffset ( )"><span class="secnum">21.4.4.11</span> Date.prototype.getTimezoneOffset ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcdate" title="Date.prototype.getUTCDate ( )"><span class="secnum">21.4.4.12</span> Date.prototype.getUTCDate ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcday" title="Date.prototype.getUTCDay ( )"><span class="secnum">21.4.4.13</span> Date.prototype.getUTCDay ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcfullyear" title="Date.prototype.getUTCFullYear ( )"><span class="secnum">21.4.4.14</span> Date.prototype.getUTCFullYear ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutchours" title="Date.prototype.getUTCHours ( )"><span class="secnum">21.4.4.15</span> Date.prototype.getUTCHours ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcmilliseconds" title="Date.prototype.getUTCMilliseconds ( )"><span class="secnum">21.4.4.16</span> Date.prototype.getUTCMilliseconds ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcminutes" title="Date.prototype.getUTCMinutes ( )"><span class="secnum">21.4.4.17</span> Date.prototype.getUTCMinutes ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcmonth" title="Date.prototype.getUTCMonth ( )"><span class="secnum">21.4.4.18</span> Date.prototype.getUTCMonth ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.getutcseconds" title="Date.prototype.getUTCSeconds ( )"><span class="secnum">21.4.4.19</span> Date.prototype.getUTCSeconds ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setdate" title="Date.prototype.setDate ( date )"><span class="secnum">21.4.4.20</span> Date.prototype.setDate ( <var>date</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setfullyear" title="Date.prototype.setFullYear ( year [ , month [ , date ] ] )"><span class="secnum">21.4.4.21</span> Date.prototype.setFullYear ( <var>year</var> [ , <var>month</var> [ , <var>date</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.sethours" title="Date.prototype.setHours ( hour [ , min [ , sec [ , ms ] ] ] )"><span class="secnum">21.4.4.22</span> Date.prototype.setHours ( <var>hour</var> [ , <var>min</var> [ , <var>sec</var> [ , <var>ms</var> ] ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setmilliseconds" title="Date.prototype.setMilliseconds ( ms )"><span class="secnum">21.4.4.23</span> Date.prototype.setMilliseconds ( <var>ms</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setminutes" title="Date.prototype.setMinutes ( min [ , sec [ , ms ] ] )"><span class="secnum">21.4.4.24</span> Date.prototype.setMinutes ( <var>min</var> [ , <var>sec</var> [ , <var>ms</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setmonth" title="Date.prototype.setMonth ( month [ , date ] )"><span class="secnum">21.4.4.25</span> Date.prototype.setMonth ( <var>month</var> [ , <var>date</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setseconds" title="Date.prototype.setSeconds ( sec [ , ms ] )"><span class="secnum">21.4.4.26</span> Date.prototype.setSeconds ( <var>sec</var> [ , <var>ms</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.settime" title="Date.prototype.setTime ( time )"><span class="secnum">21.4.4.27</span> Date.prototype.setTime ( <var>time</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutcdate" title="Date.prototype.setUTCDate ( date )"><span class="secnum">21.4.4.28</span> Date.prototype.setUTCDate ( <var>date</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutcfullyear" title="Date.prototype.setUTCFullYear ( year [ , month [ , date ] ] )"><span class="secnum">21.4.4.29</span> Date.prototype.setUTCFullYear ( <var>year</var> [ , <var>month</var> [ , <var>date</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutchours" title="Date.prototype.setUTCHours ( hour [ , min [ , sec [ , ms ] ] ] )"><span class="secnum">21.4.4.30</span> Date.prototype.setUTCHours ( <var>hour</var> [ , <var>min</var> [ , <var>sec</var> [ , <var>ms</var> ] ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutcmilliseconds" title="Date.prototype.setUTCMilliseconds ( ms )"><span class="secnum">21.4.4.31</span> Date.prototype.setUTCMilliseconds ( <var>ms</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutcminutes" title="Date.prototype.setUTCMinutes ( min [ , sec [ , ms ] ] )"><span class="secnum">21.4.4.32</span> Date.prototype.setUTCMinutes ( <var>min</var> [ , <var>sec</var> [ , <var>ms</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutcmonth" title="Date.prototype.setUTCMonth ( month [ , date ] )"><span class="secnum">21.4.4.33</span> Date.prototype.setUTCMonth ( <var>month</var> [ , <var>date</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.setutcseconds" title="Date.prototype.setUTCSeconds ( sec [ , ms ] )"><span class="secnum">21.4.4.34</span> Date.prototype.setUTCSeconds ( <var>sec</var> [ , <var>ms</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.todatestring" title="Date.prototype.toDateString ( )"><span class="secnum">21.4.4.35</span> Date.prototype.toDateString ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.toisostring" title="Date.prototype.toISOString ( )"><span class="secnum">21.4.4.36</span> Date.prototype.toISOString ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.tojson" title="Date.prototype.toJSON ( key )"><span class="secnum">21.4.4.37</span> Date.prototype.toJSON ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.tolocaledatestring" title="Date.prototype.toLocaleDateString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">21.4.4.38</span> Date.prototype.toLocaleDateString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.tolocalestring" title="Date.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">21.4.4.39</span> Date.prototype.toLocaleString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.tolocaletimestring" title="Date.prototype.toLocaleTimeString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">21.4.4.40</span> Date.prototype.toLocaleTimeString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle">+</span><a href="numbers-and-dates.html#sec-date.prototype.tostring" title="Date.prototype.toString ( )"><span class="secnum">21.4.4.41</span> Date.prototype.toString ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-timestring" title="TimeString ( tv )"><span class="secnum">21.4.4.41.1</span> TimeString ( <var>tv</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-datestring" title="DateString ( tv )"><span class="secnum">21.4.4.41.2</span> DateString ( <var>tv</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-timezoneestring" title="TimeZoneString ( tv )"><span class="secnum">21.4.4.41.3</span> TimeZoneString ( <var>tv</var> )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-todatestring" title="ToDateString ( tv )"><span class="secnum">21.4.4.41.4</span> ToDateString ( <var>tv</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.totimestring" title="Date.prototype.toTimeString ( )"><span class="secnum">21.4.4.42</span> Date.prototype.toTimeString ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.toutcstring" title="Date.prototype.toUTCString ( )"><span class="secnum">21.4.4.43</span> Date.prototype.toUTCString ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype.valueof" title="Date.prototype.valueOf ( )"><span class="secnum">21.4.4.44</span> Date.prototype.valueOf ( )</a></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-date.prototype-%symbol.toprimitive%" title="Date.prototype [ %Symbol.toPrimitive% ] ( hint )"><span class="secnum">21.4.4.45</span> Date.prototype [ %Symbol.toPrimitive% ] ( <var>hint</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="numbers-and-dates.html#sec-properties-of-date-instances" title="Properties of Date Instances"><span class="secnum">21.4.5</span> Properties of Date Instances</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-text-processing" title="Text Processing"><span class="secnum">22</span> Text Processing</a><ol class="toc"><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string-objects" title="String Objects"><span class="secnum">22.1</span> String Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string-constructor" title="The String Constructor"><span class="secnum">22.1.1</span> The String Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string-constructor-string-value" title="String ( value )"><span class="secnum">22.1.1.1</span> String ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-properties-of-the-string-constructor" title="Properties of the String Constructor"><span class="secnum">22.1.2</span> Properties of the String Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.fromcharcode" title="String.fromCharCode ( ...codeUnits )"><span class="secnum">22.1.2.1</span> String.fromCharCode ( ...<var>codeUnits</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.fromcodepoint" title="String.fromCodePoint ( ...codePoints )"><span class="secnum">22.1.2.2</span> String.fromCodePoint ( ...<var>codePoints</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype" title="String.prototype"><span class="secnum">22.1.2.3</span> String.prototype</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.raw" title="String.raw ( template, ...substitutions )"><span class="secnum">22.1.2.4</span> String.raw ( <var>template</var>, ...<var>substitutions</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-properties-of-the-string-prototype-object" title="Properties of the String Prototype Object"><span class="secnum">22.1.3</span> Properties of the String Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.at" title="String.prototype.at ( index )"><span class="secnum">22.1.3.1</span> String.prototype.at ( <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.charat" title="String.prototype.charAt ( pos )"><span class="secnum">22.1.3.2</span> String.prototype.charAt ( <var>pos</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.charcodeat" title="String.prototype.charCodeAt ( pos )"><span class="secnum">22.1.3.3</span> String.prototype.charCodeAt ( <var>pos</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.codepointat" title="String.prototype.codePointAt ( pos )"><span class="secnum">22.1.3.4</span> String.prototype.codePointAt ( <var>pos</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.concat" title="String.prototype.concat ( ...args )"><span class="secnum">22.1.3.5</span> String.prototype.concat ( ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.constructor" title="String.prototype.constructor"><span class="secnum">22.1.3.6</span> String.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.endswith" title="String.prototype.endsWith ( searchString [ , endPosition ] )"><span class="secnum">22.1.3.7</span> String.prototype.endsWith ( <var>searchString</var> [ , <var>endPosition</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.includes" title="String.prototype.includes ( searchString [ , position ] )"><span class="secnum">22.1.3.8</span> String.prototype.includes ( <var>searchString</var> [ , <var>position</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.indexof" title="String.prototype.indexOf ( searchString [ , position ] )"><span class="secnum">22.1.3.9</span> String.prototype.indexOf ( <var>searchString</var> [ , <var>position</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.iswellformed" title="String.prototype.isWellFormed ( )"><span class="secnum">22.1.3.10</span> String.prototype.isWellFormed ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.lastindexof" title="String.prototype.lastIndexOf ( searchString [ , position ] )"><span class="secnum">22.1.3.11</span> String.prototype.lastIndexOf ( <var>searchString</var> [ , <var>position</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.localecompare" title="String.prototype.localeCompare ( that [ , reserved1 [ , reserved2 ] ] )"><span class="secnum">22.1.3.12</span> String.prototype.localeCompare ( <var>that</var> [ , <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.match" title="String.prototype.match ( regexp )"><span class="secnum">22.1.3.13</span> String.prototype.match ( <var>regexp</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.matchall" title="String.prototype.matchAll ( regexp )"><span class="secnum">22.1.3.14</span> String.prototype.matchAll ( <var>regexp</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.normalize" title="String.prototype.normalize ( [ form ] )"><span class="secnum">22.1.3.15</span> String.prototype.normalize ( [ <var>form</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.padend" title="String.prototype.padEnd ( maxLength [ , fillString ] )"><span class="secnum">22.1.3.16</span> String.prototype.padEnd ( <var>maxLength</var> [ , <var>fillString</var> ] )</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string.prototype.padstart" title="String.prototype.padStart ( maxLength [ , fillString ] )"><span class="secnum">22.1.3.17</span> String.prototype.padStart ( <var>maxLength</var> [ , <var>fillString</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-stringpaddingbuiltinsimpl" title="StringPaddingBuiltinsImpl ( O, maxLength, fillString, placement )"><span class="secnum">22.1.3.17.1</span> StringPaddingBuiltinsImpl ( <var>O</var>, <var>maxLength</var>, <var>fillString</var>, <var>placement</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-stringpad" title="StringPad ( S, maxLength, fillString, placement )"><span class="secnum">22.1.3.17.2</span> StringPad ( <var>S</var>, <var>maxLength</var>, <var>fillString</var>, <var>placement</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-tozeropaddeddecimalstring" title="ToZeroPaddedDecimalString ( n, minLength )"><span class="secnum">22.1.3.17.3</span> ToZeroPaddedDecimalString ( <var>n</var>, <var>minLength</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.repeat" title="String.prototype.repeat ( count )"><span class="secnum">22.1.3.18</span> String.prototype.repeat ( <var>count</var> )</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string.prototype.replace" title="String.prototype.replace ( searchValue, replaceValue )"><span class="secnum">22.1.3.19</span> String.prototype.replace ( <var>searchValue</var>, <var>replaceValue</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-getsubstitution" title="GetSubstitution ( matched, str, position, captures, namedCaptures, replacementTemplate )"><span class="secnum">22.1.3.19.1</span> GetSubstitution ( <var>matched</var>, <var>str</var>, <var>position</var>, <var>captures</var>, <var>namedCaptures</var>, <var>replacementTemplate</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.replaceall" title="String.prototype.replaceAll ( searchValue, replaceValue )"><span class="secnum">22.1.3.20</span> String.prototype.replaceAll ( <var>searchValue</var>, <var>replaceValue</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.search" title="String.prototype.search ( regexp )"><span class="secnum">22.1.3.21</span> String.prototype.search ( <var>regexp</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.slice" title="String.prototype.slice ( start, end )"><span class="secnum">22.1.3.22</span> String.prototype.slice ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.split" title="String.prototype.split ( separator, limit )"><span class="secnum">22.1.3.23</span> String.prototype.split ( <var>separator</var>, <var>limit</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.startswith" title="String.prototype.startsWith ( searchString [ , position ] )"><span class="secnum">22.1.3.24</span> String.prototype.startsWith ( <var>searchString</var> [ , <var>position</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.substring" title="String.prototype.substring ( start, end )"><span class="secnum">22.1.3.25</span> String.prototype.substring ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.tolocalelowercase" title="String.prototype.toLocaleLowerCase ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">22.1.3.26</span> String.prototype.toLocaleLowerCase ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.tolocaleuppercase" title="String.prototype.toLocaleUpperCase ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">22.1.3.27</span> String.prototype.toLocaleUpperCase ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.tolowercase" title="String.prototype.toLowerCase ( )"><span class="secnum">22.1.3.28</span> String.prototype.toLowerCase ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.tostring" title="String.prototype.toString ( )"><span class="secnum">22.1.3.29</span> String.prototype.toString ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.touppercase" title="String.prototype.toUpperCase ( )"><span class="secnum">22.1.3.30</span> String.prototype.toUpperCase ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.towellformed" title="String.prototype.toWellFormed ( )"><span class="secnum">22.1.3.31</span> String.prototype.toWellFormed ( )</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string.prototype.trim" title="String.prototype.trim ( )"><span class="secnum">22.1.3.32</span> String.prototype.trim ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-trimstring" title="TrimString ( string, where )"><span class="secnum">22.1.3.32.1</span> TrimString ( <var>string</var>, <var>where</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.trimend" title="String.prototype.trimEnd ( )"><span class="secnum">22.1.3.33</span> String.prototype.trimEnd ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype.trimstart" title="String.prototype.trimStart ( )"><span class="secnum">22.1.3.34</span> String.prototype.trimStart ( )</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string.prototype.valueof" title="String.prototype.valueOf ( )"><span class="secnum">22.1.3.35</span> String.prototype.valueOf ( )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-thisstringvalue" title="ThisStringValue ( value )"><span class="secnum">22.1.3.35.1</span> ThisStringValue ( <var>value</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-string.prototype-%symbol.iterator%" title="String.prototype [ %Symbol.iterator% ] ( )"><span class="secnum">22.1.3.36</span> String.prototype [ %Symbol.iterator% ] ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-properties-of-string-instances" title="Properties of String Instances"><span class="secnum">22.1.4</span> Properties of String Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-properties-of-string-instances-length" title="length"><span class="secnum">22.1.4.1</span> length</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-string-iterator-objects" title="String Iterator Objects"><span class="secnum">22.1.5</span> String Iterator Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="text-processing.html#sec-%stringiteratorprototype%-object" title="The %StringIteratorPrototype% Object"><span class="secnum">22.1.5.1</span> The %StringIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-%stringiteratorprototype%.next" title="%StringIteratorPrototype%.next ( )"><span class="secnum">22.1.5.1.1</span> %StringIteratorPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-%stringiteratorprototype%-%symbol.tostringtag%" title="%StringIteratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">22.1.5.1.2</span> %StringIteratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-regexp-regular-expression-objects" title="RegExp (Regular Expression) Objects"><span class="secnum">22.2</span> RegExp (Regular Expression) Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="text-processing.html#sec-patterns" title="Patterns"><span class="secnum">22.2.1</span> Patterns</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-patterns-static-semantics-early-errors" title="Static Semantics: Early Errors"><span class="secnum">22.2.1.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-countleftcapturingparenswithin" title="Static Semantics: CountLeftCapturingParensWithin ( node )"><span class="secnum">22.2.1.2</span> SS: CountLeftCapturingParensWithin ( <var>node</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-countleftcapturingparensbefore" title="Static Semantics: CountLeftCapturingParensBefore ( node )"><span class="secnum">22.2.1.3</span> SS: CountLeftCapturingParensBefore ( <var>node</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-mightbothparticipate" title="Static Semantics: MightBothParticipate ( x, y )"><span class="secnum">22.2.1.4</span> SS: MightBothParticipate ( <var>x</var>, <var>y</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-patterns-static-semantics-capturing-group-number" title="Static Semantics: CapturingGroupNumber"><span class="secnum">22.2.1.5</span> SS: CapturingGroupNumber</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-patterns-static-semantics-is-character-class" title="Static Semantics: IsCharacterClass"><span class="secnum">22.2.1.6</span> SS: IsCharacterClass</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-patterns-static-semantics-character-value" title="Static Semantics: CharacterValue"><span class="secnum">22.2.1.7</span> SS: CharacterValue</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-static-semantics-maycontainstrings" title="Static Semantics: MayContainStrings"><span class="secnum">22.2.1.8</span> SS: MayContainStrings</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-groupspecifiersthatmatch" title="Static Semantics: GroupSpecifiersThatMatch ( thisGroupName )"><span class="secnum">22.2.1.9</span> SS: GroupSpecifiersThatMatch ( <var>thisGroupName</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-static-semantics-capturinggroupname" title="Static Semantics: CapturingGroupName"><span class="secnum">22.2.1.10</span> SS: CapturingGroupName</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpidentifiercodepoints" title="Static Semantics: RegExpIdentifierCodePoints"><span class="secnum">22.2.1.11</span> SS: RegExpIdentifierCodePoints</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpidentifiercodepoint" title="Static Semantics: RegExpIdentifierCodePoint"><span class="secnum">22.2.1.12</span> SS: RegExpIdentifierCodePoint</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-pattern-semantics" title="Pattern Semantics"><span class="secnum">22.2.2</span> Pattern Semantics</a><ol class="toc"><li><span class="item-toggle">+</span><a href="text-processing.html#sec-pattern-notation" title="Notation"><span class="secnum">22.2.2.1</span> Notation</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp-records" title="RegExp Records"><span class="secnum">22.2.2.1.1</span> RegExp Records</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-compilepattern" title="Runtime Semantics: CompilePattern"><span class="secnum">22.2.2.2</span> RS: CompilePattern</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-compilesubpattern" title="Runtime Semantics: CompileSubpattern"><span class="secnum">22.2.2.3</span> RS: CompileSubpattern</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-repeatmatcher-abstract-operation" title="RepeatMatcher ( m, min, max, greedy, x, c, parenIndex, parenCount )"><span class="secnum">22.2.2.3.1</span> RepeatMatcher ( <var>m</var>, <var>min</var>, <var>max</var>, <var>greedy</var>, <var>x</var>, <var>c</var>, <var>parenIndex</var>, <var>parenCount</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-emptymatcher" title="EmptyMatcher ( )"><span class="secnum">22.2.2.3.2</span> EmptyMatcher ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-matchtwoalternatives" title="MatchTwoAlternatives ( m1, m2 )"><span class="secnum">22.2.2.3.3</span> MatchTwoAlternatives ( <var>m1</var>, <var>m2</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-matchsequence" title="MatchSequence ( m1, m2, direction )"><span class="secnum">22.2.2.3.4</span> MatchSequence ( <var>m1</var>, <var>m2</var>, <var>direction</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-compileassertion" title="Runtime Semantics: CompileAssertion"><span class="secnum">22.2.2.4</span> RS: CompileAssertion</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-iswordchar-abstract-operation" title="IsWordChar ( rer, Input, e )"><span class="secnum">22.2.2.4.1</span> IsWordChar ( <var>rer</var>, <var>Input</var>, <var>e</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-compilequantifier" title="Runtime Semantics: CompileQuantifier"><span class="secnum">22.2.2.5</span> RS: CompileQuantifier</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-compilequantifierprefix" title="Runtime Semantics: CompileQuantifierPrefix"><span class="secnum">22.2.2.6</span> RS: CompileQuantifierPrefix</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-compileatom" title="Runtime Semantics: CompileAtom"><span class="secnum">22.2.2.7</span> RS: CompileAtom</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-charactersetmatcher-abstract-operation" title="CharacterSetMatcher ( rer, A, invert, direction )"><span class="secnum">22.2.2.7.1</span> CharacterSetMatcher ( <var>rer</var>, <var>A</var>, <var>invert</var>, <var>direction</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-backreference-matcher" title="BackreferenceMatcher ( rer, ns, direction )"><span class="secnum">22.2.2.7.2</span> BackreferenceMatcher ( <var>rer</var>, <var>ns</var>, <var>direction</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-canonicalize-ch" title="Canonicalize ( rer, ch )"><span class="secnum">22.2.2.7.3</span> Canonicalize ( <var>rer</var>, <var>ch</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-updatemodifiers" title="UpdateModifiers ( rer, add, remove )"><span class="secnum">22.2.2.7.4</span> UpdateModifiers ( <var>rer</var>, <var>add</var>, <var>remove</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-compilecharacterclass" title="Runtime Semantics: CompileCharacterClass"><span class="secnum">22.2.2.8</span> RS: CompileCharacterClass</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-compiletocharset" title="Runtime Semantics: CompileToCharSet"><span class="secnum">22.2.2.9</span> RS: CompileToCharSet</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-characterrange-abstract-operation" title="CharacterRange ( A, B )"><span class="secnum">22.2.2.9.1</span> CharacterRange ( <var>A</var>, <var>B</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-haseitherunicodeflag-abstract-operation" title="HasEitherUnicodeFlag ( rer )"><span class="secnum">22.2.2.9.2</span> HasEitherUnicodeFlag ( <var>rer</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-wordcharacters" title="WordCharacters ( rer )"><span class="secnum">22.2.2.9.3</span> WordCharacters ( <var>rer</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-allcharacters" title="AllCharacters ( rer )"><span class="secnum">22.2.2.9.4</span> AllCharacters ( <var>rer</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-maybesimplecasefolding" title="MaybeSimpleCaseFolding ( rer, A )"><span class="secnum">22.2.2.9.5</span> MaybeSimpleCaseFolding ( <var>rer</var>, <var>A</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-charactercomplement" title="CharacterComplement ( rer, S )"><span class="secnum">22.2.2.9.6</span> CharacterComplement ( <var>rer</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-unicodematchproperty-p" title="UnicodeMatchProperty ( rer, p )"><span class="secnum">22.2.2.9.7</span> UnicodeMatchProperty ( <var>rer</var>, <var>p</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-runtime-semantics-unicodematchpropertyvalue-p-v" title="UnicodeMatchPropertyValue ( p, v )"><span class="secnum">22.2.2.9.8</span> UnicodeMatchPropertyValue ( <var>p</var>, <var>v</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-compileclasssetstring" title="Runtime Semantics: CompileClassSetString"><span class="secnum">22.2.2.10</span> RS: CompileClassSetString</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-abstract-operations-for-regexp-creation" title="Abstract Operations for RegExp Creation"><span class="secnum">22.2.3</span> Abstract Operations for RegExp Creation</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpcreate" title="RegExpCreate ( P, F )"><span class="secnum">22.2.3.1</span> RegExpCreate ( <var>P</var>, <var>F</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpalloc" title="RegExpAlloc ( newTarget )"><span class="secnum">22.2.3.2</span> RegExpAlloc ( <var>newTarget</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpinitialize" title="RegExpInitialize ( obj, pattern, flags )"><span class="secnum">22.2.3.3</span> RegExpInitialize ( <var>obj</var>, <var>pattern</var>, <var>flags</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-parsepattern" title="Static Semantics: ParsePattern ( patternText, u, v )"><span class="secnum">22.2.3.4</span> SS: ParsePattern ( <var>patternText</var>, <var>u</var>, <var>v</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-regexp-constructor" title="The RegExp Constructor"><span class="secnum">22.2.4</span> The RegExp Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp-pattern-flags" title="RegExp ( pattern, flags )"><span class="secnum">22.2.4.1</span> RegExp ( <var>pattern</var>, <var>flags</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-properties-of-the-regexp-constructor" title="Properties of the RegExp Constructor"><span class="secnum">22.2.5</span> Properties of the RegExp Constructor</a><ol class="toc"><li><span class="item-toggle">+</span><a href="text-processing.html#sec-regexp.escape" title="RegExp.escape ( S )"><span class="secnum">22.2.5.1</span> RegExp.escape ( <var>S</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-encodeforregexpescape" title="EncodeForRegExpEscape ( cp )"><span class="secnum">22.2.5.1.1</span> EncodeForRegExpEscape ( <var>cp</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype" title="RegExp.prototype"><span class="secnum">22.2.5.2</span> RegExp.prototype</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp-%symbol.species%" title="get RegExp [ %Symbol.species% ]"><span class="secnum">22.2.5.3</span> get RegExp [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-properties-of-the-regexp-prototype-object" title="Properties of the RegExp Prototype Object"><span class="secnum">22.2.6</span> Properties of the RegExp Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype.constructor" title="RegExp.prototype.constructor"><span class="secnum">22.2.6.1</span> RegExp.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype.exec" title="RegExp.prototype.exec ( string )"><span class="secnum">22.2.6.2</span> RegExp.prototype.exec ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.dotAll" title="get RegExp.prototype.dotAll"><span class="secnum">22.2.6.3</span> get RegExp.prototype.dotAll</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-get-regexp.prototype.flags" title="get RegExp.prototype.flags"><span class="secnum">22.2.6.4</span> get RegExp.prototype.flags</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexphasflag" title="RegExpHasFlag ( R, codeUnit )"><span class="secnum">22.2.6.4.1</span> RegExpHasFlag ( <var>R</var>, <var>codeUnit</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.global" title="get RegExp.prototype.global"><span class="secnum">22.2.6.5</span> get RegExp.prototype.global</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.hasIndices" title="get RegExp.prototype.hasIndices"><span class="secnum">22.2.6.6</span> get RegExp.prototype.hasIndices</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.ignorecase" title="get RegExp.prototype.ignoreCase"><span class="secnum">22.2.6.7</span> get RegExp.prototype.ignoreCase</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype-%symbol.match%" title="RegExp.prototype [ %Symbol.match% ] ( string )"><span class="secnum">22.2.6.8</span> RegExp.prototype [ %Symbol.match% ] ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp-prototype-%symbol.matchall%" title="RegExp.prototype [ %Symbol.matchAll% ] ( string )"><span class="secnum">22.2.6.9</span> RegExp.prototype [ %Symbol.matchAll% ] ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.multiline" title="get RegExp.prototype.multiline"><span class="secnum">22.2.6.10</span> get RegExp.prototype.multiline</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype-%symbol.replace%" title="RegExp.prototype [ %Symbol.replace% ] ( string, replaceValue )"><span class="secnum">22.2.6.11</span> RegExp.prototype [ %Symbol.replace% ] ( <var>string</var>, <var>replaceValue</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype-%symbol.search%" title="RegExp.prototype [ %Symbol.search% ] ( string )"><span class="secnum">22.2.6.12</span> RegExp.prototype [ %Symbol.search% ] ( <var>string</var> )</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-get-regexp.prototype.source" title="get RegExp.prototype.source"><span class="secnum">22.2.6.13</span> get RegExp.prototype.source</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-escaperegexppattern" title="EscapeRegExpPattern ( P, F )"><span class="secnum">22.2.6.13.1</span> EscapeRegExpPattern ( <var>P</var>, <var>F</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype-%symbol.split%" title="RegExp.prototype [ %Symbol.split% ] ( string, limit )"><span class="secnum">22.2.6.14</span> RegExp.prototype [ %Symbol.split% ] ( <var>string</var>, <var>limit</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.sticky" title="get RegExp.prototype.sticky"><span class="secnum">22.2.6.15</span> get RegExp.prototype.sticky</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype.test" title="RegExp.prototype.test ( S )"><span class="secnum">22.2.6.16</span> RegExp.prototype.test ( <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexp.prototype.tostring" title="RegExp.prototype.toString ( )"><span class="secnum">22.2.6.17</span> RegExp.prototype.toString ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.unicode" title="get RegExp.prototype.unicode"><span class="secnum">22.2.6.18</span> get RegExp.prototype.unicode</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-get-regexp.prototype.unicodesets" title="get RegExp.prototype.unicodeSets"><span class="secnum">22.2.6.19</span> get RegExp.prototype.unicodeSets</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-abstract-operations-for-regexp-matching" title="Abstract Operations for RegExp Matching"><span class="secnum">22.2.7</span> Abstract Operations for RegExp Matching</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpexec" title="RegExpExec ( R, S )"><span class="secnum">22.2.7.1</span> RegExpExec ( <var>R</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-regexpbuiltinexec" title="RegExpBuiltinExec ( R, S )"><span class="secnum">22.2.7.2</span> RegExpBuiltinExec ( <var>R</var>, <var>S</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-advancestringindex" title="AdvanceStringIndex ( S, index, unicode )"><span class="secnum">22.2.7.3</span> AdvanceStringIndex ( <var>S</var>, <var>index</var>, <var>unicode</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-getstringindex" title="GetStringIndex ( S, codePointIndex )"><span class="secnum">22.2.7.4</span> GetStringIndex ( <var>S</var>, <var>codePointIndex</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-match-records" title="Match Records"><span class="secnum">22.2.7.5</span> Match Records</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-getmatchstring" title="GetMatchString ( S, match )"><span class="secnum">22.2.7.6</span> GetMatchString ( <var>S</var>, <var>match</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-getmatchindexpair" title="GetMatchIndexPair ( S, match )"><span class="secnum">22.2.7.7</span> GetMatchIndexPair ( <var>S</var>, <var>match</var> )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-makematchindicesindexpairarray" title="MakeMatchIndicesIndexPairArray ( S, indices, groupNames, hasGroups )"><span class="secnum">22.2.7.8</span> MakeMatchIndicesIndexPairArray ( <var>S</var>, <var>indices</var>, <var>groupNames</var>, <var>hasGroups</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-properties-of-regexp-instances" title="Properties of RegExp Instances"><span class="secnum">22.2.8</span> Properties of RegExp Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-lastindex" title="lastIndex"><span class="secnum">22.2.8.1</span> lastIndex</a></li></ol></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-regexp-string-iterator-objects" title="RegExp String Iterator Objects"><span class="secnum">22.2.9</span> RegExp String Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-createregexpstringiterator" title="CreateRegExpStringIterator ( R, S, global, fullUnicode )"><span class="secnum">22.2.9.1</span> CreateRegExpStringIterator ( <var>R</var>, <var>S</var>, <var>global</var>, <var>fullUnicode</var> )</a></li><li><span class="item-toggle">+</span><a href="text-processing.html#sec-%regexpstringiteratorprototype%-object" title="The %RegExpStringIteratorPrototype% Object"><span class="secnum">22.2.9.2</span> The %RegExpStringIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-%regexpstringiteratorprototype%.next" title="%RegExpStringIteratorPrototype%.next ( )"><span class="secnum">22.2.9.2.1</span> %RegExpStringIteratorPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-%regexpstringiteratorprototype%-%symbol.tostringtag%" title="%RegExpStringIteratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">22.2.9.2.2</span> %RegExpStringIteratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="text-processing.html#sec-properties-of-regexp-string-iterator-instances" title="Properties of RegExp String Iterator Instances"><span class="secnum">22.2.9.3</span> Properties of RegExp String Iterator Instances</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-indexed-collections" title="Indexed Collections"><span class="secnum">23</span> Indexed Collections</a><ol class="toc"><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array-objects" title="Array Objects"><span class="secnum">23.1</span> Array Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array-constructor" title="The Array Constructor"><span class="secnum">23.1.1</span> The Array Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array" title="Array ( ...values )"><span class="secnum">23.1.1.1</span> Array ( ...<var>values</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-the-array-constructor" title="Properties of the Array Constructor"><span class="secnum">23.1.2</span> Properties of the Array Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.from" title="Array.from ( items [ , mapper [ , thisArg ] ] )"><span class="secnum">23.1.2.1</span> Array.from ( <var>items</var> [ , <var>mapper</var> [ , <var>thisArg</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.fromasync" title="Array.fromAsync ( items [ , mapper [ , thisArg ] ] )"><span class="secnum">23.1.2.2</span> Array.fromAsync ( <var>items</var> [ , <var>mapper</var> [ , <var>thisArg</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.isarray" title="Array.isArray ( arg )"><span class="secnum">23.1.2.3</span> Array.isArray ( <var>arg</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.of" title="Array.of ( ...items )"><span class="secnum">23.1.2.4</span> Array.of ( ...<var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype" title="Array.prototype"><span class="secnum">23.1.2.5</span> Array.prototype</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-array-%symbol.species%" title="get Array [ %Symbol.species% ]"><span class="secnum">23.1.2.6</span> get Array [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-the-array-prototype-object" title="Properties of the Array Prototype Object"><span class="secnum">23.1.3</span> Properties of the Array Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.at" title="Array.prototype.at ( index )"><span class="secnum">23.1.3.1</span> Array.prototype.at ( <var>index</var> )</a></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array.prototype.concat" title="Array.prototype.concat ( ...items )"><span class="secnum">23.1.3.2</span> Array.prototype.concat ( ...<var>items</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-isconcatspreadable" title="IsConcatSpreadable ( O )"><span class="secnum">23.1.3.2.1</span> IsConcatSpreadable ( <var>O</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.constructor" title="Array.prototype.constructor"><span class="secnum">23.1.3.3</span> Array.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.copywithin" title="Array.prototype.copyWithin ( target, start [ , end ] )"><span class="secnum">23.1.3.4</span> Array.prototype.copyWithin ( <var>target</var>, <var>start</var> [ , <var>end</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.entries" title="Array.prototype.entries ( )"><span class="secnum">23.1.3.5</span> Array.prototype.entries ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.every" title="Array.prototype.every ( callback [ , thisArg ] )"><span class="secnum">23.1.3.6</span> Array.prototype.every ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.fill" title="Array.prototype.fill ( value [ , start [ , end ] ] )"><span class="secnum">23.1.3.7</span> Array.prototype.fill ( <var>value</var> [ , <var>start</var> [ , <var>end</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.filter" title="Array.prototype.filter ( callback [ , thisArg ] )"><span class="secnum">23.1.3.8</span> Array.prototype.filter ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.find" title="Array.prototype.find ( predicate [ , thisArg ] )"><span class="secnum">23.1.3.9</span> Array.prototype.find ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.findindex" title="Array.prototype.findIndex ( predicate [ , thisArg ] )"><span class="secnum">23.1.3.10</span> Array.prototype.findIndex ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.findlast" title="Array.prototype.findLast ( predicate [ , thisArg ] )"><span class="secnum">23.1.3.11</span> Array.prototype.findLast ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array.prototype.findlastindex" title="Array.prototype.findLastIndex ( predicate [ , thisArg ] )"><span class="secnum">23.1.3.12</span> Array.prototype.findLastIndex ( <var>predicate</var> [ , <var>thisArg</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-findviapredicate" title="FindViaPredicate ( O, len, direction, predicate, thisArg )"><span class="secnum">23.1.3.12.1</span> FindViaPredicate ( <var>O</var>, <var>len</var>, <var>direction</var>, <var>predicate</var>, <var>thisArg</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array.prototype.flat" title="Array.prototype.flat ( [ depth ] )"><span class="secnum">23.1.3.13</span> Array.prototype.flat ( [ <var>depth</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-flattenintoarray" title="FlattenIntoArray ( target, source, sourceLen, start, depth [ , mapperFunction [ , thisArg ] ] )"><span class="secnum">23.1.3.13.1</span> FlattenIntoArray ( <var>target</var>, <var>source</var>, <var>sourceLen</var>, <var>start</var>, <var>depth</var> [ , <var>mapperFunction</var> [ , <var>thisArg</var> ] ] )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.flatmap" title="Array.prototype.flatMap ( mapperFunction [ , thisArg ] )"><span class="secnum">23.1.3.14</span> Array.prototype.flatMap ( <var>mapperFunction</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.foreach" title="Array.prototype.forEach ( callback [ , thisArg ] )"><span class="secnum">23.1.3.15</span> Array.prototype.forEach ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.includes" title="Array.prototype.includes ( searchElement [ , fromIndex ] )"><span class="secnum">23.1.3.16</span> Array.prototype.includes ( <var>searchElement</var> [ , <var>fromIndex</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.indexof" title="Array.prototype.indexOf ( searchElement [ , fromIndex ] )"><span class="secnum">23.1.3.17</span> Array.prototype.indexOf ( <var>searchElement</var> [ , <var>fromIndex</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.join" title="Array.prototype.join ( separator )"><span class="secnum">23.1.3.18</span> Array.prototype.join ( <var>separator</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.keys" title="Array.prototype.keys ( )"><span class="secnum">23.1.3.19</span> Array.prototype.keys ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.lastindexof" title="Array.prototype.lastIndexOf ( searchElement [ , fromIndex ] )"><span class="secnum">23.1.3.20</span> Array.prototype.lastIndexOf ( <var>searchElement</var> [ , <var>fromIndex</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.map" title="Array.prototype.map ( callback [ , thisArg ] )"><span class="secnum">23.1.3.21</span> Array.prototype.map ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.pop" title="Array.prototype.pop ( )"><span class="secnum">23.1.3.22</span> Array.prototype.pop ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.push" title="Array.prototype.push ( ...items )"><span class="secnum">23.1.3.23</span> Array.prototype.push ( ...<var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.reduce" title="Array.prototype.reduce ( callback [ , initialValue ] )"><span class="secnum">23.1.3.24</span> Array.prototype.reduce ( <var>callback</var> [ , <var>initialValue</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.reduceright" title="Array.prototype.reduceRight ( callback [ , initialValue ] )"><span class="secnum">23.1.3.25</span> Array.prototype.reduceRight ( <var>callback</var> [ , <var>initialValue</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.reverse" title="Array.prototype.reverse ( )"><span class="secnum">23.1.3.26</span> Array.prototype.reverse ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.shift" title="Array.prototype.shift ( )"><span class="secnum">23.1.3.27</span> Array.prototype.shift ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.slice" title="Array.prototype.slice ( start, end )"><span class="secnum">23.1.3.28</span> Array.prototype.slice ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.some" title="Array.prototype.some ( callback [ , thisArg ] )"><span class="secnum">23.1.3.29</span> Array.prototype.some ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array.prototype.sort" title="Array.prototype.sort ( comparator )"><span class="secnum">23.1.3.30</span> Array.prototype.sort ( <var>comparator</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-sortindexedproperties" title="SortIndexedProperties ( obj, len, SortCompare, holes )"><span class="secnum">23.1.3.30.1</span> SortIndexedProperties ( <var>obj</var>, <var>len</var>, <var>SortCompare</var>, <var>holes</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-comparearrayelements" title="CompareArrayElements ( x, y, comparator )"><span class="secnum">23.1.3.30.2</span> CompareArrayElements ( <var>x</var>, <var>y</var>, <var>comparator</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.splice" title="Array.prototype.splice ( start, deleteCount, ...items )"><span class="secnum">23.1.3.31</span> Array.prototype.splice ( <var>start</var>, <var>deleteCount</var>, ...<var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.tolocalestring" title="Array.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">23.1.3.32</span> Array.prototype.toLocaleString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.toreversed" title="Array.prototype.toReversed ( )"><span class="secnum">23.1.3.33</span> Array.prototype.toReversed ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.tosorted" title="Array.prototype.toSorted ( comparator )"><span class="secnum">23.1.3.34</span> Array.prototype.toSorted ( <var>comparator</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.tospliced" title="Array.prototype.toSpliced ( start, skipCount, ...items )"><span class="secnum">23.1.3.35</span> Array.prototype.toSpliced ( <var>start</var>, <var>skipCount</var>, ...<var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.tostring" title="Array.prototype.toString ( )"><span class="secnum">23.1.3.36</span> Array.prototype.toString ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.unshift" title="Array.prototype.unshift ( ...items )"><span class="secnum">23.1.3.37</span> Array.prototype.unshift ( ...<var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.values" title="Array.prototype.values ( )"><span class="secnum">23.1.3.38</span> Array.prototype.values ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype.with" title="Array.prototype.with ( index, value )"><span class="secnum">23.1.3.39</span> Array.prototype.with ( <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype-%symbol.iterator%" title="Array.prototype [ %Symbol.iterator% ] ( )"><span class="secnum">23.1.3.40</span> Array.prototype [ %Symbol.iterator% ] ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-array.prototype-%symbol.unscopables%" title="Array.prototype [ %Symbol.unscopables% ]"><span class="secnum">23.1.3.41</span> Array.prototype [ %Symbol.unscopables% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-array-instances" title="Properties of Array Instances"><span class="secnum">23.1.4</span> Properties of Array Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-properties-of-array-instances-length" title="length"><span class="secnum">23.1.4.1</span> length</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-array-iterator-objects" title="Array Iterator Objects"><span class="secnum">23.1.5</span> Array Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-createarrayiterator" title="CreateArrayIterator ( array, kind )"><span class="secnum">23.1.5.1</span> CreateArrayIterator ( <var>array</var>, <var>kind</var> )</a></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-%arrayiteratorprototype%-object" title="The %ArrayIteratorPrototype% Object"><span class="secnum">23.1.5.2</span> The %ArrayIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%arrayiteratorprototype%.next" title="%ArrayIteratorPrototype%.next ( )"><span class="secnum">23.1.5.2.1</span> %ArrayIteratorPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%arrayiteratorprototype%-%symbol.tostringtag%" title="%ArrayIteratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">23.1.5.2.2</span> %ArrayIteratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-properties-of-array-iterator-instances" title="Properties of Array Iterator Instances"><span class="secnum">23.1.5.3</span> Properties of Array Iterator Instances</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-typedarray-objects" title="TypedArray Objects"><span class="secnum">23.2</span> TypedArray Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-%typedarray%-intrinsic-object" title="The %TypedArray% Intrinsic Object"><span class="secnum">23.2.1</span> The %TypedArray% Intrinsic Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%" title="%TypedArray% ( )"><span class="secnum">23.2.1.1</span> %TypedArray% ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-the-%typedarray%-intrinsic-object" title="Properties of the %TypedArray% Intrinsic Object"><span class="secnum">23.2.2</span> Properties of the %TypedArray% Intrinsic Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.from" title="%TypedArray%.from ( source [ , mapper [ , thisArg ] ] )"><span class="secnum">23.2.2.1</span> %TypedArray%.from ( <var>source</var> [ , <var>mapper</var> [ , <var>thisArg</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.of" title="%TypedArray%.of ( ...items )"><span class="secnum">23.2.2.2</span> %TypedArray%.of ( ...<var>items</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype" title="%TypedArray%.prototype"><span class="secnum">23.2.2.3</span> %TypedArray%.prototype</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-%typedarray%-%symbol.species%" title="get %TypedArray% [ %Symbol.species% ]"><span class="secnum">23.2.2.4</span> get %TypedArray% [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-the-%typedarrayprototype%-object" title="Properties of the %TypedArray% Prototype Object"><span class="secnum">23.2.3</span> Properties of the %TypedArray% Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.at" title="%TypedArray%.prototype.at ( index )"><span class="secnum">23.2.3.1</span> %TypedArray%.prototype.at ( <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-%typedarray%.prototype.buffer" title="get %TypedArray%.prototype.buffer"><span class="secnum">23.2.3.2</span> get %TypedArray%.prototype.buffer</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-%typedarray%.prototype.bytelength" title="get %TypedArray%.prototype.byteLength"><span class="secnum">23.2.3.3</span> get %TypedArray%.prototype.byteLength</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-%typedarray%.prototype.byteoffset" title="get %TypedArray%.prototype.byteOffset"><span class="secnum">23.2.3.4</span> get %TypedArray%.prototype.byteOffset</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.constructor" title="%TypedArray%.prototype.constructor"><span class="secnum">23.2.3.5</span> %TypedArray%.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.copywithin" title="%TypedArray%.prototype.copyWithin ( target, start [ , end ] )"><span class="secnum">23.2.3.6</span> %TypedArray%.prototype.copyWithin ( <var>target</var>, <var>start</var> [ , <var>end</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.entries" title="%TypedArray%.prototype.entries ( )"><span class="secnum">23.2.3.7</span> %TypedArray%.prototype.entries ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.every" title="%TypedArray%.prototype.every ( callback [ , thisArg ] )"><span class="secnum">23.2.3.8</span> %TypedArray%.prototype.every ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.fill" title="%TypedArray%.prototype.fill ( value [ , start [ , end ] ] )"><span class="secnum">23.2.3.9</span> %TypedArray%.prototype.fill ( <var>value</var> [ , <var>start</var> [ , <var>end</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.filter" title="%TypedArray%.prototype.filter ( callback [ , thisArg ] )"><span class="secnum">23.2.3.10</span> %TypedArray%.prototype.filter ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.find" title="%TypedArray%.prototype.find ( predicate [ , thisArg ] )"><span class="secnum">23.2.3.11</span> %TypedArray%.prototype.find ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.findindex" title="%TypedArray%.prototype.findIndex ( predicate [ , thisArg ] )"><span class="secnum">23.2.3.12</span> %TypedArray%.prototype.findIndex ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.findlast" title="%TypedArray%.prototype.findLast ( predicate [ , thisArg ] )"><span class="secnum">23.2.3.13</span> %TypedArray%.prototype.findLast ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.findlastindex" title="%TypedArray%.prototype.findLastIndex ( predicate [ , thisArg ] )"><span class="secnum">23.2.3.14</span> %TypedArray%.prototype.findLastIndex ( <var>predicate</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.foreach" title="%TypedArray%.prototype.forEach ( callback [ , thisArg ] )"><span class="secnum">23.2.3.15</span> %TypedArray%.prototype.forEach ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.includes" title="%TypedArray%.prototype.includes ( searchElement [ , fromIndex ] )"><span class="secnum">23.2.3.16</span> %TypedArray%.prototype.includes ( <var>searchElement</var> [ , <var>fromIndex</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.indexof" title="%TypedArray%.prototype.indexOf ( searchElement [ , fromIndex ] )"><span class="secnum">23.2.3.17</span> %TypedArray%.prototype.indexOf ( <var>searchElement</var> [ , <var>fromIndex</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.join" title="%TypedArray%.prototype.join ( separator )"><span class="secnum">23.2.3.18</span> %TypedArray%.prototype.join ( <var>separator</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.keys" title="%TypedArray%.prototype.keys ( )"><span class="secnum">23.2.3.19</span> %TypedArray%.prototype.keys ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.lastindexof" title="%TypedArray%.prototype.lastIndexOf ( searchElement [ , fromIndex ] )"><span class="secnum">23.2.3.20</span> %TypedArray%.prototype.lastIndexOf ( <var>searchElement</var> [ , <var>fromIndex</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-%typedarray%.prototype.length" title="get %TypedArray%.prototype.length"><span class="secnum">23.2.3.21</span> get %TypedArray%.prototype.length</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.map" title="%TypedArray%.prototype.map ( callback [ , thisArg ] )"><span class="secnum">23.2.3.22</span> %TypedArray%.prototype.map ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.reduce" title="%TypedArray%.prototype.reduce ( callback [ , initialValue ] )"><span class="secnum">23.2.3.23</span> %TypedArray%.prototype.reduce ( <var>callback</var> [ , <var>initialValue</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.reduceright" title="%TypedArray%.prototype.reduceRight ( callback [ , initialValue ] )"><span class="secnum">23.2.3.24</span> %TypedArray%.prototype.reduceRight ( <var>callback</var> [ , <var>initialValue</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.reverse" title="%TypedArray%.prototype.reverse ( )"><span class="secnum">23.2.3.25</span> %TypedArray%.prototype.reverse ( )</a></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-%typedarray%.prototype.set" title="%TypedArray%.prototype.set ( source [ , offset ] )"><span class="secnum">23.2.3.26</span> %TypedArray%.prototype.set ( <var>source</var> [ , <var>offset</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-settypedarrayfromarraylike" title="SetTypedArrayFromArrayLike ( target, targetOffset, source )"><span class="secnum">23.2.3.26.1</span> SetTypedArrayFromArrayLike ( <var>target</var>, <var>targetOffset</var>, <var>source</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-settypedarrayfromtypedarray" title="SetTypedArrayFromTypedArray ( target, targetOffset, source )"><span class="secnum">23.2.3.26.2</span> SetTypedArrayFromTypedArray ( <var>target</var>, <var>targetOffset</var>, <var>source</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.slice" title="%TypedArray%.prototype.slice ( start, end )"><span class="secnum">23.2.3.27</span> %TypedArray%.prototype.slice ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.some" title="%TypedArray%.prototype.some ( callback [ , thisArg ] )"><span class="secnum">23.2.3.28</span> %TypedArray%.prototype.some ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.sort" title="%TypedArray%.prototype.sort ( comparator )"><span class="secnum">23.2.3.29</span> %TypedArray%.prototype.sort ( <var>comparator</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.subarray" title="%TypedArray%.prototype.subarray ( start, end )"><span class="secnum">23.2.3.30</span> %TypedArray%.prototype.subarray ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.tolocalestring" title="%TypedArray%.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )"><span class="secnum">23.2.3.31</span> %TypedArray%.prototype.toLocaleString ( [ <var>reserved1</var> [ , <var>reserved2</var> ] ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.toreversed" title="%TypedArray%.prototype.toReversed ( )"><span class="secnum">23.2.3.32</span> %TypedArray%.prototype.toReversed ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.tosorted" title="%TypedArray%.prototype.toSorted ( comparator )"><span class="secnum">23.2.3.33</span> %TypedArray%.prototype.toSorted ( <var>comparator</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.tostring" title="%TypedArray%.prototype.toString ( )"><span class="secnum">23.2.3.34</span> %TypedArray%.prototype.toString ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.values" title="%TypedArray%.prototype.values ( )"><span class="secnum">23.2.3.35</span> %TypedArray%.prototype.values ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype.with" title="%TypedArray%.prototype.with ( index, value )"><span class="secnum">23.2.3.36</span> %TypedArray%.prototype.with ( <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-%typedarray%.prototype-%symbol.iterator%" title="%TypedArray%.prototype [ %Symbol.iterator% ] ( )"><span class="secnum">23.2.3.37</span> %TypedArray%.prototype [ %Symbol.iterator% ] ( )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-get-%typedarray%.prototype-%symbol.tostringtag%" title="get %TypedArray%.prototype [ %Symbol.toStringTag% ]"><span class="secnum">23.2.3.38</span> get %TypedArray%.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-abstract-operations-for-typedarray-objects" title="Abstract Operations for TypedArray Objects"><span class="secnum">23.2.4</span> Abstract Operations for TypedArray Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarraycreatefromconstructor" title="TypedArrayCreateFromConstructor ( constructor, argumentList )"><span class="secnum">23.2.4.1</span> TypedArrayCreateFromConstructor ( <var>constructor</var>, <var>argumentList</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarray-create-same-type" title="TypedArrayCreateSameType ( exemplar, length )"><span class="secnum">23.2.4.2</span> TypedArrayCreateSameType ( <var>exemplar</var>, <var>length</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#typedarray-species-create" title="TypedArraySpeciesCreate ( exemplar, argumentList )"><span class="secnum">23.2.4.3</span> TypedArraySpeciesCreate ( <var>exemplar</var>, <var>argumentList</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-validatetypedarray" title="ValidateTypedArray ( O, order )"><span class="secnum">23.2.4.4</span> ValidateTypedArray ( <var>O</var>, <var>order</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarrayelementsize" title="TypedArrayElementSize ( O )"><span class="secnum">23.2.4.5</span> TypedArrayElementSize ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarrayelementtype" title="TypedArrayElementType ( O )"><span class="secnum">23.2.4.6</span> TypedArrayElementType ( <var>O</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-comparetypedarrayelements" title="CompareTypedArrayElements ( x, y, comparator )"><span class="secnum">23.2.4.7</span> CompareTypedArrayElements ( <var>x</var>, <var>y</var>, <var>comparator</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-typedarray-constructors" title="The TypedArray Constructors"><span class="secnum">23.2.5</span> The <var>TypedArray</var> Constructors</a><ol class="toc"><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-typedarray" title="TypedArray ( ...args )"><span class="secnum">23.2.5.1</span> <var>TypedArray</var> ( ...<var>args</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-allocatetypedarray" title="AllocateTypedArray ( constructorName, newTarget, defaultProto [ , length ] )"><span class="secnum">23.2.5.1.1</span> AllocateTypedArray ( <var>constructorName</var>, <var>newTarget</var>, <var>defaultProto</var> [ , <var>length</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-initializetypedarrayfromtypedarray" title="InitializeTypedArrayFromTypedArray ( O, srcArray )"><span class="secnum">23.2.5.1.2</span> InitializeTypedArrayFromTypedArray ( <var>O</var>, <var>srcArray</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-initializetypedarrayfromarraybuffer" title="InitializeTypedArrayFromArrayBuffer ( O, buffer, byteOffset, length )"><span class="secnum">23.2.5.1.3</span> InitializeTypedArrayFromArrayBuffer ( <var>O</var>, <var>buffer</var>, <var>byteOffset</var>, <var>length</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-initializetypedarrayfromlist" title="InitializeTypedArrayFromList ( O, values )"><span class="secnum">23.2.5.1.4</span> InitializeTypedArrayFromList ( <var>O</var>, <var>values</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-initializetypedarrayfromarraylike" title="InitializeTypedArrayFromArrayLike ( O, arrayLike )"><span class="secnum">23.2.5.1.5</span> InitializeTypedArrayFromArrayLike ( <var>O</var>, <var>arrayLike</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-allocatetypedarraybuffer" title="AllocateTypedArrayBuffer ( O, length )"><span class="secnum">23.2.5.1.6</span> AllocateTypedArrayBuffer ( <var>O</var>, <var>length</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-the-typedarray-constructors" title="Properties of the TypedArray Constructors"><span class="secnum">23.2.6</span> Properties of the <var>TypedArray</var> Constructors</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarray.bytes_per_element" title="TypedArray.BYTES_PER_ELEMENT"><span class="secnum">23.2.6.1</span> <var>TypedArray</var>.BYTES_PER_ELEMENT</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarray.prototype" title="TypedArray.prototype"><span class="secnum">23.2.6.2</span> <var>TypedArray</var>.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-properties-of-typedarray-prototype-objects" title="Properties of the TypedArray Prototype Objects"><span class="secnum">23.2.7</span> Properties of the <var>TypedArray</var> Prototype Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarray.prototype.bytes_per_element" title="TypedArray.prototype.BYTES_PER_ELEMENT"><span class="secnum">23.2.7.1</span> <var>TypedArray</var>.prototype.BYTES_PER_ELEMENT</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-typedarray.prototype.constructor" title="TypedArray.prototype.constructor"><span class="secnum">23.2.7.2</span> <var>TypedArray</var>.prototype.constructor</a></li></ol></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-properties-of-typedarray-instances" title="Properties of TypedArray Instances"><span class="secnum">23.2.8</span> Properties of <var>TypedArray</var> Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-uint8array" title="Uint8Array Objects"><span class="secnum">23.3</span> Uint8Array Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-additional-properties-of-the-uint8array-constructor" title="Additional Properties of the Uint8Array Constructor"><span class="secnum">23.3.1</span> Additional Properties of the Uint8Array Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-uint8array.frombase64" title="Uint8Array.fromBase64 ( string [ , options ] )"><span class="secnum">23.3.1.1</span> Uint8Array.fromBase64 ( <var>string</var> [ , <var>options</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-uint8array.fromhex" title="Uint8Array.fromHex ( string )"><span class="secnum">23.3.1.2</span> Uint8Array.fromHex ( <var>string</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-additional-properties-of-the-uint8array-prototype-object" title="Additional Properties of the Uint8Array Prototype Object"><span class="secnum">23.3.2</span> Additional Properties of the Uint8Array Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-uint8array.prototype.setfrombase64" title="Uint8Array.prototype.setFromBase64 ( string [ , options ] )"><span class="secnum">23.3.2.1</span> Uint8Array.prototype.setFromBase64 ( <var>string</var> [ , <var>options</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-uint8array.prototype.setfromhex" title="Uint8Array.prototype.setFromHex ( string )"><span class="secnum">23.3.2.2</span> Uint8Array.prototype.setFromHex ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-uint8array.prototype.tobase64" title="Uint8Array.prototype.toBase64 ( [ options ] )"><span class="secnum">23.3.2.3</span> Uint8Array.prototype.toBase64 ( [ <var>options</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-uint8array.prototype.tohex" title="Uint8Array.prototype.toHex ( )"><span class="secnum">23.3.2.4</span> Uint8Array.prototype.toHex ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="indexed-collections.html#sec-abstract-operations-for-uint8array-objects" title="Abstract Operations for Uint8Array Objects"><span class="secnum">23.3.3</span> Abstract Operations for Uint8Array Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-validateuint8array" title="ValidateUint8Array ( ta )"><span class="secnum">23.3.3.1</span> ValidateUint8Array ( <var>ta</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-getuint8arraybytes" title="GetUint8ArrayBytes ( ta )"><span class="secnum">23.3.3.2</span> GetUint8ArrayBytes ( <var>ta</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-setuint8arraybytes" title="SetUint8ArrayBytes ( into, bytes )"><span class="secnum">23.3.3.3</span> SetUint8ArrayBytes ( <var>into</var>, <var>bytes</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-skipasciiwhitespace" title="SkipAsciiWhitespace ( string, index )"><span class="secnum">23.3.3.4</span> SkipAsciiWhitespace ( <var>string</var>, <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-decodefinalbase64chunk" title="DecodeFinalBase64Chunk ( chunk, throwOnExtraBits )"><span class="secnum">23.3.3.5</span> DecodeFinalBase64Chunk ( <var>chunk</var>, <var>throwOnExtraBits</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-decodefulllengthbase64chunk" title="DecodeFullLengthBase64Chunk ( chunk )"><span class="secnum">23.3.3.6</span> DecodeFullLengthBase64Chunk ( <var>chunk</var> )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-frombase64" title="FromBase64 ( string, alphabet, lastChunkHandling [ , maxLength ] )"><span class="secnum">23.3.3.7</span> FromBase64 ( <var>string</var>, <var>alphabet</var>, <var>lastChunkHandling</var> [ , <var>maxLength</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="indexed-collections.html#sec-fromhex" title="FromHex ( string [ , maxLength ] )"><span class="secnum">23.3.3.8</span> FromHex ( <var>string</var> [ , <var>maxLength</var> ] )</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-keyed-collections" title="Keyed Collections"><span class="secnum">24</span> Keyed Collections</a><ol class="toc"><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-map-objects" title="Map Objects"><span class="secnum">24.1</span> Map Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-map-constructor" title="The Map Constructor"><span class="secnum">24.1.1</span> The Map Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map-iterable" title="Map ( [ iterable ] )"><span class="secnum">24.1.1.1</span> Map ( [ <var>iterable</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-add-entries-from-iterable" title="AddEntriesFromIterable ( target, iterable, adder )"><span class="secnum">24.1.1.2</span> AddEntriesFromIterable ( <var>target</var>, <var>iterable</var>, <var>adder</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-map-constructor" title="Properties of the Map Constructor"><span class="secnum">24.1.2</span> Properties of the Map Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.groupby" title="Map.groupBy ( items, callback )"><span class="secnum">24.1.2.1</span> Map.groupBy ( <var>items</var>, <var>callback</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype" title="Map.prototype"><span class="secnum">24.1.2.2</span> Map.prototype</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-get-map-%symbol.species%" title="get Map [ %Symbol.species% ]"><span class="secnum">24.1.2.3</span> get Map [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-map-prototype-object" title="Properties of the Map Prototype Object"><span class="secnum">24.1.3</span> Properties of the Map Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.clear" title="Map.prototype.clear ( )"><span class="secnum">24.1.3.1</span> Map.prototype.clear ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.constructor" title="Map.prototype.constructor"><span class="secnum">24.1.3.2</span> Map.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.delete" title="Map.prototype.delete ( key )"><span class="secnum">24.1.3.3</span> Map.prototype.delete ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.entries" title="Map.prototype.entries ( )"><span class="secnum">24.1.3.4</span> Map.prototype.entries ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.foreach" title="Map.prototype.forEach ( callback [ , thisArg ] )"><span class="secnum">24.1.3.5</span> Map.prototype.forEach ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.get" title="Map.prototype.get ( key )"><span class="secnum">24.1.3.6</span> Map.prototype.get ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.getorinsert" title="Map.prototype.getOrInsert ( key, value )"><span class="secnum">24.1.3.7</span> Map.prototype.getOrInsert ( <var>key</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.getorinsertcomputed" title="Map.prototype.getOrInsertComputed ( key, callback )"><span class="secnum">24.1.3.8</span> Map.prototype.getOrInsertComputed ( <var>key</var>, <var>callback</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.has" title="Map.prototype.has ( key )"><span class="secnum">24.1.3.9</span> Map.prototype.has ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.keys" title="Map.prototype.keys ( )"><span class="secnum">24.1.3.10</span> Map.prototype.keys ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.set" title="Map.prototype.set ( key, value )"><span class="secnum">24.1.3.11</span> Map.prototype.set ( <var>key</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-get-map.prototype.size" title="get Map.prototype.size"><span class="secnum">24.1.3.12</span> get Map.prototype.size</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype.values" title="Map.prototype.values ( )"><span class="secnum">24.1.3.13</span> Map.prototype.values ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype-%symbol.iterator%" title="Map.prototype [ %Symbol.iterator% ] ( )"><span class="secnum">24.1.3.14</span> Map.prototype [ %Symbol.iterator% ] ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-map.prototype-%symbol.tostringtag%" title="Map.prototype [ %Symbol.toStringTag% ]"><span class="secnum">24.1.3.15</span> Map.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-properties-of-map-instances" title="Properties of Map Instances"><span class="secnum">24.1.4</span> Properties of Map Instances</a></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-map-iterator-objects" title="Map Iterator Objects"><span class="secnum">24.1.5</span> Map Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-createmapiterator" title="CreateMapIterator ( map, kind )"><span class="secnum">24.1.5.1</span> CreateMapIterator ( <var>map</var>, <var>kind</var> )</a></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-%mapiteratorprototype%-object" title="The %MapIteratorPrototype% Object"><span class="secnum">24.1.5.2</span> The %MapIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-%mapiteratorprototype%.next" title="%MapIteratorPrototype%.next ( )"><span class="secnum">24.1.5.2.1</span> %MapIteratorPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-%mapiteratorprototype%-%symbol.tostringtag%" title="%MapIteratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">24.1.5.2.2</span> %MapIteratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-set-objects" title="Set Objects"><span class="secnum">24.2</span> Set Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-abstract-operations-for-set-objects" title="Abstract Operations For Set Objects"><span class="secnum">24.2.1</span> Abstract Operations For Set Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set-records" title="Set Records"><span class="secnum">24.2.1.1</span> Set Records</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-getsetrecord" title="GetSetRecord ( obj )"><span class="secnum">24.2.1.2</span> GetSetRecord ( <var>obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-setdatahas" title="SetDataHas ( setData, value )"><span class="secnum">24.2.1.3</span> SetDataHas ( <var>setData</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-setdataindex" title="SetDataIndex ( setData, value )"><span class="secnum">24.2.1.4</span> SetDataIndex ( <var>setData</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-setdatasize" title="SetDataSize ( setData )"><span class="secnum">24.2.1.5</span> SetDataSize ( <var>setData</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-set-constructor" title="The Set Constructor"><span class="secnum">24.2.2</span> The Set Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set-iterable" title="Set ( [ iterable ] )"><span class="secnum">24.2.2.1</span> Set ( [ <var>iterable</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-set-constructor" title="Properties of the Set Constructor"><span class="secnum">24.2.3</span> Properties of the Set Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype" title="Set.prototype"><span class="secnum">24.2.3.1</span> Set.prototype</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-get-set-%symbol.species%" title="get Set [ %Symbol.species% ]"><span class="secnum">24.2.3.2</span> get Set [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-set-prototype-object" title="Properties of the Set Prototype Object"><span class="secnum">24.2.4</span> Properties of the Set Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.add" title="Set.prototype.add ( value )"><span class="secnum">24.2.4.1</span> Set.prototype.add ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.clear" title="Set.prototype.clear ( )"><span class="secnum">24.2.4.2</span> Set.prototype.clear ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.constructor" title="Set.prototype.constructor"><span class="secnum">24.2.4.3</span> Set.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.delete" title="Set.prototype.delete ( value )"><span class="secnum">24.2.4.4</span> Set.prototype.delete ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.difference" title="Set.prototype.difference ( other )"><span class="secnum">24.2.4.5</span> Set.prototype.difference ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.entries" title="Set.prototype.entries ( )"><span class="secnum">24.2.4.6</span> Set.prototype.entries ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.foreach" title="Set.prototype.forEach ( callback [ , thisArg ] )"><span class="secnum">24.2.4.7</span> Set.prototype.forEach ( <var>callback</var> [ , <var>thisArg</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.has" title="Set.prototype.has ( value )"><span class="secnum">24.2.4.8</span> Set.prototype.has ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.intersection" title="Set.prototype.intersection ( other )"><span class="secnum">24.2.4.9</span> Set.prototype.intersection ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.isdisjointfrom" title="Set.prototype.isDisjointFrom ( other )"><span class="secnum">24.2.4.10</span> Set.prototype.isDisjointFrom ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.issubsetof" title="Set.prototype.isSubsetOf ( other )"><span class="secnum">24.2.4.11</span> Set.prototype.isSubsetOf ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.issupersetof" title="Set.prototype.isSupersetOf ( other )"><span class="secnum">24.2.4.12</span> Set.prototype.isSupersetOf ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.keys" title="Set.prototype.keys ( )"><span class="secnum">24.2.4.13</span> Set.prototype.keys ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-get-set.prototype.size" title="get Set.prototype.size"><span class="secnum">24.2.4.14</span> get Set.prototype.size</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.symmetricdifference" title="Set.prototype.symmetricDifference ( other )"><span class="secnum">24.2.4.15</span> Set.prototype.symmetricDifference ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.union" title="Set.prototype.union ( other )"><span class="secnum">24.2.4.16</span> Set.prototype.union ( <var>other</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype.values" title="Set.prototype.values ( )"><span class="secnum">24.2.4.17</span> Set.prototype.values ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype-%symbol.iterator%" title="Set.prototype [ %Symbol.iterator% ] ( )"><span class="secnum">24.2.4.18</span> Set.prototype [ %Symbol.iterator% ] ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-set.prototype-%symbol.tostringtag%" title="Set.prototype [ %Symbol.toStringTag% ]"><span class="secnum">24.2.4.19</span> Set.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-properties-of-set-instances" title="Properties of Set Instances"><span class="secnum">24.2.5</span> Properties of Set Instances</a></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-set-iterator-objects" title="Set Iterator Objects"><span class="secnum">24.2.6</span> Set Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-createsetiterator" title="CreateSetIterator ( set, kind )"><span class="secnum">24.2.6.1</span> CreateSetIterator ( <var>set</var>, <var>kind</var> )</a></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-%setiteratorprototype%-object" title="The %SetIteratorPrototype% Object"><span class="secnum">24.2.6.2</span> The %SetIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-%setiteratorprototype%.next" title="%SetIteratorPrototype%.next ( )"><span class="secnum">24.2.6.2.1</span> %SetIteratorPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-%setiteratorprototype%-%symbol.tostringtag%" title="%SetIteratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">24.2.6.2.2</span> %SetIteratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-weakmap-objects" title="WeakMap Objects"><span class="secnum">24.3</span> WeakMap Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-weakmap-constructor" title="The WeakMap Constructor"><span class="secnum">24.3.1</span> The WeakMap Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap-iterable" title="WeakMap ( [ iterable ] )"><span class="secnum">24.3.1.1</span> WeakMap ( [ <var>iterable</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-weakmap-constructor" title="Properties of the WeakMap Constructor"><span class="secnum">24.3.2</span> Properties of the WeakMap Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype" title="WeakMap.prototype"><span class="secnum">24.3.2.1</span> WeakMap.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-weakmap-prototype-object" title="Properties of the WeakMap Prototype Object"><span class="secnum">24.3.3</span> Properties of the WeakMap Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.constructor" title="WeakMap.prototype.constructor"><span class="secnum">24.3.3.1</span> WeakMap.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.delete" title="WeakMap.prototype.delete ( key )"><span class="secnum">24.3.3.2</span> WeakMap.prototype.delete ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.get" title="WeakMap.prototype.get ( key )"><span class="secnum">24.3.3.3</span> WeakMap.prototype.get ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.getorinsert" title="WeakMap.prototype.getOrInsert ( key, value )"><span class="secnum">24.3.3.4</span> WeakMap.prototype.getOrInsert ( <var>key</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.getorinsertcomputed" title="WeakMap.prototype.getOrInsertComputed ( key, callback )"><span class="secnum">24.3.3.5</span> WeakMap.prototype.getOrInsertComputed ( <var>key</var>, <var>callback</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.has" title="WeakMap.prototype.has ( key )"><span class="secnum">24.3.3.6</span> WeakMap.prototype.has ( <var>key</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype.set" title="WeakMap.prototype.set ( key, value )"><span class="secnum">24.3.3.7</span> WeakMap.prototype.set ( <var>key</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakmap.prototype-%symbol.tostringtag%" title="WeakMap.prototype [ %Symbol.toStringTag% ]"><span class="secnum">24.3.3.8</span> WeakMap.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-properties-of-weakmap-instances" title="Properties of WeakMap Instances"><span class="secnum">24.3.4</span> Properties of WeakMap Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-weakset-objects" title="WeakSet Objects"><span class="secnum">24.4</span> WeakSet Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-weakset-constructor" title="The WeakSet Constructor"><span class="secnum">24.4.1</span> The WeakSet Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset-iterable" title="WeakSet ( [ iterable ] )"><span class="secnum">24.4.1.1</span> WeakSet ( [ <var>iterable</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-weakset-constructor" title="Properties of the WeakSet Constructor"><span class="secnum">24.4.2</span> Properties of the WeakSet Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset.prototype" title="WeakSet.prototype"><span class="secnum">24.4.2.1</span> WeakSet.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-properties-of-the-weakset-prototype-object" title="Properties of the WeakSet Prototype Object"><span class="secnum">24.4.3</span> Properties of the WeakSet Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset.prototype.add" title="WeakSet.prototype.add ( value )"><span class="secnum">24.4.3.1</span> WeakSet.prototype.add ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset.prototype.constructor" title="WeakSet.prototype.constructor"><span class="secnum">24.4.3.2</span> WeakSet.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset.prototype.delete" title="WeakSet.prototype.delete ( value )"><span class="secnum">24.4.3.3</span> WeakSet.prototype.delete ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset.prototype.has" title="WeakSet.prototype.has ( value )"><span class="secnum">24.4.3.4</span> WeakSet.prototype.has ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-weakset.prototype-%symbol.tostringtag%" title="WeakSet.prototype [ %Symbol.toStringTag% ]"><span class="secnum">24.4.3.5</span> WeakSet.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-properties-of-weakset-instances" title="Properties of WeakSet Instances"><span class="secnum">24.4.4</span> Properties of WeakSet Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="keyed-collections.html#sec-abstract-operations-for-keyed-collections" title="Abstract Operations for Keyed Collections"><span class="secnum">24.5</span> Abstract Operations for Keyed Collections</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="keyed-collections.html#sec-canonicalizekeyedcollectionkey" title="CanonicalizeKeyedCollectionKey ( key )"><span class="secnum">24.5.1</span> CanonicalizeKeyedCollectionKey ( <var>key</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-structured-data" title="Structured Data"><span class="secnum">25</span> Structured Data</a><ol class="toc"><li><span class="item-toggle">+</span><a href="structured-data.html#sec-arraybuffer-objects" title="ArrayBuffer Objects"><span class="secnum">25.1</span> ArrayBuffer Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer-notation" title="Notation"><span class="secnum">25.1.1</span> Notation</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-fixed-length-and-resizable-arraybuffer-objects" title="Fixed-length and Resizable ArrayBuffer Objects"><span class="secnum">25.1.2</span> Fixed-length and Resizable ArrayBuffer Objects</a></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-abstract-operations-for-arraybuffer-objects" title="Abstract Operations For ArrayBuffer Objects"><span class="secnum">25.1.3</span> Abstract Operations For ArrayBuffer Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-allocatearraybuffer" title="AllocateArrayBuffer ( constructor, byteLength [ , maxByteLength ] )"><span class="secnum">25.1.3.1</span> AllocateArrayBuffer ( <var>constructor</var>, <var>byteLength</var> [ , <var>maxByteLength</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybufferbytelength" title="ArrayBufferByteLength ( arrayBuffer, order )"><span class="secnum">25.1.3.2</span> ArrayBufferByteLength ( <var>arrayBuffer</var>, <var>order</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffercopyanddetach" title="ArrayBufferCopyAndDetach ( arrayBuffer, newLength, preserveResizability )"><span class="secnum">25.1.3.3</span> ArrayBufferCopyAndDetach ( <var>arrayBuffer</var>, <var>newLength</var>, <var>preserveResizability</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isdetachedbuffer" title="IsDetachedBuffer ( arrayBuffer )"><span class="secnum">25.1.3.4</span> IsDetachedBuffer ( <var>arrayBuffer</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-detacharraybuffer" title="DetachArrayBuffer ( arrayBuffer [ , key ] )"><span class="secnum">25.1.3.5</span> DetachArrayBuffer ( <var>arrayBuffer</var> [ , <var>key</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-clonearraybuffer" title="CloneArrayBuffer ( srcBuffer, srcByteOffset, srcLength )"><span class="secnum">25.1.3.6</span> CloneArrayBuffer ( <var>srcBuffer</var>, <var>srcByteOffset</var>, <var>srcLength</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getarraybuffermaxbytelengthoption" title="GetArrayBufferMaxByteLengthOption ( options )"><span class="secnum">25.1.3.7</span> GetArrayBufferMaxByteLengthOption ( <var>options</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-hostresizearraybuffer" title="HostResizeArrayBuffer ( buffer, newByteLength )"><span class="secnum">25.1.3.8</span> HostResizeArrayBuffer ( <var>buffer</var>, <var>newByteLength</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isfixedlengtharraybuffer" title="IsFixedLengthArrayBuffer ( arrayBuffer )"><span class="secnum">25.1.3.9</span> IsFixedLengthArrayBuffer ( <var>arrayBuffer</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isunsignedelementtype" title="IsUnsignedElementType ( type )"><span class="secnum">25.1.3.10</span> IsUnsignedElementType ( <var>type</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isunclampedintegerelementtype" title="IsUnclampedIntegerElementType ( type )"><span class="secnum">25.1.3.11</span> IsUnclampedIntegerElementType ( <var>type</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isbigintelementtype" title="IsBigIntElementType ( type )"><span class="secnum">25.1.3.12</span> IsBigIntElementType ( <var>type</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isnotearconfiguration" title="IsNoTearConfiguration ( type, order )"><span class="secnum">25.1.3.13</span> IsNoTearConfiguration ( <var>type</var>, <var>order</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-rawbytestonumeric" title="RawBytesToNumeric ( type, rawBytes, isLittleEndian )"><span class="secnum">25.1.3.14</span> RawBytesToNumeric ( <var>type</var>, <var>rawBytes</var>, <var>isLittleEndian</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getrawbytesfromsharedblock" title="GetRawBytesFromSharedBlock ( block, byteIndex, type, isTypedArray, order )"><span class="secnum">25.1.3.15</span> GetRawBytesFromSharedBlock ( <var>block</var>, <var>byteIndex</var>, <var>type</var>, <var>isTypedArray</var>, <var>order</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getvaluefrombuffer" title="GetValueFromBuffer ( arrayBuffer, byteIndex, type, isTypedArray, order [ , isLittleEndian ] )"><span class="secnum">25.1.3.16</span> GetValueFromBuffer ( <var>arrayBuffer</var>, <var>byteIndex</var>, <var>type</var>, <var>isTypedArray</var>, <var>order</var> [ , <var>isLittleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-numerictorawbytes" title="NumericToRawBytes ( type, value, isLittleEndian )"><span class="secnum">25.1.3.17</span> NumericToRawBytes ( <var>type</var>, <var>value</var>, <var>isLittleEndian</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-setvalueinbuffer" title="SetValueInBuffer ( arrayBuffer, byteIndex, type, value, isTypedArray, order [ , isLittleEndian ] )"><span class="secnum">25.1.3.18</span> SetValueInBuffer ( <var>arrayBuffer</var>, <var>byteIndex</var>, <var>type</var>, <var>value</var>, <var>isTypedArray</var>, <var>order</var> [ , <var>isLittleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getmodifysetvalueinbuffer" title="GetModifySetValueInBuffer ( arrayBuffer, byteIndex, type, value, op )"><span class="secnum">25.1.3.19</span> GetModifySetValueInBuffer ( <var>arrayBuffer</var>, <var>byteIndex</var>, <var>type</var>, <var>value</var>, <var>op</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-arraybuffer-constructor" title="The ArrayBuffer Constructor"><span class="secnum">25.1.4</span> The ArrayBuffer Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer-length" title="ArrayBuffer ( length [ , options ] )"><span class="secnum">25.1.4.1</span> ArrayBuffer ( <var>length</var> [ , <var>options</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-properties-of-the-arraybuffer-constructor" title="Properties of the ArrayBuffer Constructor"><span class="secnum">25.1.5</span> Properties of the ArrayBuffer Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.isview" title="ArrayBuffer.isView ( arg )"><span class="secnum">25.1.5.1</span> ArrayBuffer.isView ( <var>arg</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype" title="ArrayBuffer.prototype"><span class="secnum">25.1.5.2</span> ArrayBuffer.prototype</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-arraybuffer-%symbol.species%" title="get ArrayBuffer [ %Symbol.species% ]"><span class="secnum">25.1.5.3</span> get ArrayBuffer [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-properties-of-the-arraybuffer-prototype-object" title="Properties of the ArrayBuffer Prototype Object"><span class="secnum">25.1.6</span> Properties of the ArrayBuffer Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-arraybuffer.prototype.bytelength" title="get ArrayBuffer.prototype.byteLength"><span class="secnum">25.1.6.1</span> get ArrayBuffer.prototype.byteLength</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype.constructor" title="ArrayBuffer.prototype.constructor"><span class="secnum">25.1.6.2</span> ArrayBuffer.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-arraybuffer.prototype.detached" title="get ArrayBuffer.prototype.detached"><span class="secnum">25.1.6.3</span> get ArrayBuffer.prototype.detached</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-arraybuffer.prototype.maxbytelength" title="get ArrayBuffer.prototype.maxByteLength"><span class="secnum">25.1.6.4</span> get ArrayBuffer.prototype.maxByteLength</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-arraybuffer.prototype.resizable" title="get ArrayBuffer.prototype.resizable"><span class="secnum">25.1.6.5</span> get ArrayBuffer.prototype.resizable</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype.resize" title="ArrayBuffer.prototype.resize ( newLength )"><span class="secnum">25.1.6.6</span> ArrayBuffer.prototype.resize ( <var>newLength</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype.slice" title="ArrayBuffer.prototype.slice ( start, end )"><span class="secnum">25.1.6.7</span> ArrayBuffer.prototype.slice ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype.transfer" title="ArrayBuffer.prototype.transfer ( [ newLength ] )"><span class="secnum">25.1.6.8</span> ArrayBuffer.prototype.transfer ( [ <var>newLength</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype.transfertofixedlength" title="ArrayBuffer.prototype.transferToFixedLength ( [ newLength ] )"><span class="secnum">25.1.6.9</span> ArrayBuffer.prototype.transferToFixedLength ( [ <var>newLength</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-arraybuffer.prototype-%symbol.tostringtag%" title="ArrayBuffer.prototype [ %Symbol.toStringTag% ]"><span class="secnum">25.1.6.10</span> ArrayBuffer.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-properties-of-the-arraybuffer-instances" title="Properties of ArrayBuffer Instances"><span class="secnum">25.1.7</span> Properties of ArrayBuffer Instances</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-resizable-arraybuffer-guidelines" title="Resizable ArrayBuffer Guidelines"><span class="secnum">25.1.8</span> Resizable ArrayBuffer Guidelines</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-sharedarraybuffer-objects" title="SharedArrayBuffer Objects"><span class="secnum">25.2</span> SharedArrayBuffer Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-fixed-length-and-growable-sharedarraybuffer-objects" title="Fixed-length and Growable SharedArrayBuffer Objects"><span class="secnum">25.2.1</span> Fixed-length and Growable SharedArrayBuffer Objects</a></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-abstract-operations-for-sharedarraybuffer-objects" title="Abstract Operations for SharedArrayBuffer Objects"><span class="secnum">25.2.2</span> Abstract Operations for SharedArrayBuffer Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-allocatesharedarraybuffer" title="AllocateSharedArrayBuffer ( constructor, byteLength [ , maxByteLength ] )"><span class="secnum">25.2.2.1</span> AllocateSharedArrayBuffer ( <var>constructor</var>, <var>byteLength</var> [ , <var>maxByteLength</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-issharedarraybuffer" title="IsSharedArrayBuffer ( obj )"><span class="secnum">25.2.2.2</span> IsSharedArrayBuffer ( <var>obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isgrowablesharedarraybuffer" title="IsGrowableSharedArrayBuffer ( obj )"><span class="secnum">25.2.2.3</span> IsGrowableSharedArrayBuffer ( <var>obj</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-hostgrowsharedarraybuffer" title="HostGrowSharedArrayBuffer ( buffer, newByteLength )"><span class="secnum">25.2.2.4</span> HostGrowSharedArrayBuffer ( <var>buffer</var>, <var>newByteLength</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-sharedarraybuffer-constructor" title="The SharedArrayBuffer Constructor"><span class="secnum">25.2.3</span> The SharedArrayBuffer Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer-length" title="SharedArrayBuffer ( length [ , options ] )"><span class="secnum">25.2.3.1</span> SharedArrayBuffer ( <var>length</var> [ , <var>options</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-properties-of-the-sharedarraybuffer-constructor" title="Properties of the SharedArrayBuffer Constructor"><span class="secnum">25.2.4</span> Properties of the SharedArrayBuffer Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer.prototype" title="SharedArrayBuffer.prototype"><span class="secnum">25.2.4.1</span> SharedArrayBuffer.prototype</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer-%symbol.species%" title="get SharedArrayBuffer [ %Symbol.species% ]"><span class="secnum">25.2.4.2</span> get SharedArrayBuffer [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-properties-of-the-sharedarraybuffer-prototype-object" title="Properties of the SharedArrayBuffer Prototype Object"><span class="secnum">25.2.5</span> Properties of the SharedArrayBuffer Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-sharedarraybuffer.prototype.bytelength" title="get SharedArrayBuffer.prototype.byteLength"><span class="secnum">25.2.5.1</span> get SharedArrayBuffer.prototype.byteLength</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer.prototype.constructor" title="SharedArrayBuffer.prototype.constructor"><span class="secnum">25.2.5.2</span> SharedArrayBuffer.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer.prototype.grow" title="SharedArrayBuffer.prototype.grow ( newLength )"><span class="secnum">25.2.5.3</span> SharedArrayBuffer.prototype.grow ( <var>newLength</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-sharedarraybuffer.prototype.growable" title="get SharedArrayBuffer.prototype.growable"><span class="secnum">25.2.5.4</span> get SharedArrayBuffer.prototype.growable</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-sharedarraybuffer.prototype.maxbytelength" title="get SharedArrayBuffer.prototype.maxByteLength"><span class="secnum">25.2.5.5</span> get SharedArrayBuffer.prototype.maxByteLength</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer.prototype.slice" title="SharedArrayBuffer.prototype.slice ( start, end )"><span class="secnum">25.2.5.6</span> SharedArrayBuffer.prototype.slice ( <var>start</var>, <var>end</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-sharedarraybuffer.prototype-%symbol.tostringtag%" title="SharedArrayBuffer.prototype [ %Symbol.toStringTag% ]"><span class="secnum">25.2.5.7</span> SharedArrayBuffer.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-properties-of-the-sharedarraybuffer-instances" title="Properties of SharedArrayBuffer Instances"><span class="secnum">25.2.6</span> Properties of SharedArrayBuffer Instances</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-growable-sharedarraybuffer-guidelines" title="Growable SharedArrayBuffer Guidelines"><span class="secnum">25.2.7</span> Growable SharedArrayBuffer Guidelines</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-dataview-objects" title="DataView Objects"><span class="secnum">25.3</span> DataView Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="structured-data.html#sec-abstract-operations-for-dataview-objects" title="Abstract Operations For DataView Objects"><span class="secnum">25.3.1</span> Abstract Operations For DataView Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview-with-buffer-witness-records" title="DataView With Buffer Witness Records"><span class="secnum">25.3.1.1</span> DataView With Buffer Witness Records</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-makedataviewwithbufferwitnessrecord" title="MakeDataViewWithBufferWitnessRecord ( obj, order )"><span class="secnum">25.3.1.2</span> MakeDataViewWithBufferWitnessRecord ( <var>obj</var>, <var>order</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getviewbytelength" title="GetViewByteLength ( viewRecord )"><span class="secnum">25.3.1.3</span> GetViewByteLength ( <var>viewRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-isviewoutofbounds" title="IsViewOutOfBounds ( viewRecord )"><span class="secnum">25.3.1.4</span> IsViewOutOfBounds ( <var>viewRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getviewvalue" title="GetViewValue ( view, requestIndex, isLittleEndian, type )"><span class="secnum">25.3.1.5</span> GetViewValue ( <var>view</var>, <var>requestIndex</var>, <var>isLittleEndian</var>, <var>type</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-setviewvalue" title="SetViewValue ( view, requestIndex, isLittleEndian, type, value )"><span class="secnum">25.3.1.6</span> SetViewValue ( <var>view</var>, <var>requestIndex</var>, <var>isLittleEndian</var>, <var>type</var>, <var>value</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-dataview-constructor" title="The DataView Constructor"><span class="secnum">25.3.2</span> The DataView Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview-buffer-byteoffset-bytelength" title="DataView ( buffer [ , byteOffset [ , byteLength ] ] )"><span class="secnum">25.3.2.1</span> DataView ( <var>buffer</var> [ , <var>byteOffset</var> [ , <var>byteLength</var> ] ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-properties-of-the-dataview-constructor" title="Properties of the DataView Constructor"><span class="secnum">25.3.3</span> Properties of the DataView Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype" title="DataView.prototype"><span class="secnum">25.3.3.1</span> DataView.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-properties-of-the-dataview-prototype-object" title="Properties of the DataView Prototype Object"><span class="secnum">25.3.4</span> Properties of the DataView Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-dataview.prototype.buffer" title="get DataView.prototype.buffer"><span class="secnum">25.3.4.1</span> get DataView.prototype.buffer</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-dataview.prototype.bytelength" title="get DataView.prototype.byteLength"><span class="secnum">25.3.4.2</span> get DataView.prototype.byteLength</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-get-dataview.prototype.byteoffset" title="get DataView.prototype.byteOffset"><span class="secnum">25.3.4.3</span> get DataView.prototype.byteOffset</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.constructor" title="DataView.prototype.constructor"><span class="secnum">25.3.4.4</span> DataView.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getbigint64" title="DataView.prototype.getBigInt64 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.5</span> DataView.prototype.getBigInt64 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getbiguint64" title="DataView.prototype.getBigUint64 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.6</span> DataView.prototype.getBigUint64 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getfloat16" title="DataView.prototype.getFloat16 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.7</span> DataView.prototype.getFloat16 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getfloat32" title="DataView.prototype.getFloat32 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.8</span> DataView.prototype.getFloat32 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getfloat64" title="DataView.prototype.getFloat64 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.9</span> DataView.prototype.getFloat64 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getint8" title="DataView.prototype.getInt8 ( byteOffset )"><span class="secnum">25.3.4.10</span> DataView.prototype.getInt8 ( <var>byteOffset</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getint16" title="DataView.prototype.getInt16 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.11</span> DataView.prototype.getInt16 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getint32" title="DataView.prototype.getInt32 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.12</span> DataView.prototype.getInt32 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getuint8" title="DataView.prototype.getUint8 ( byteOffset )"><span class="secnum">25.3.4.13</span> DataView.prototype.getUint8 ( <var>byteOffset</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getuint16" title="DataView.prototype.getUint16 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.14</span> DataView.prototype.getUint16 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.getuint32" title="DataView.prototype.getUint32 ( byteOffset [ , littleEndian ] )"><span class="secnum">25.3.4.15</span> DataView.prototype.getUint32 ( <var>byteOffset</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setbigint64" title="DataView.prototype.setBigInt64 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.16</span> DataView.prototype.setBigInt64 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setbiguint64" title="DataView.prototype.setBigUint64 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.17</span> DataView.prototype.setBigUint64 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setfloat16" title="DataView.prototype.setFloat16 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.18</span> DataView.prototype.setFloat16 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setfloat32" title="DataView.prototype.setFloat32 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.19</span> DataView.prototype.setFloat32 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setfloat64" title="DataView.prototype.setFloat64 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.20</span> DataView.prototype.setFloat64 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setint8" title="DataView.prototype.setInt8 ( byteOffset, value )"><span class="secnum">25.3.4.21</span> DataView.prototype.setInt8 ( <var>byteOffset</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setint16" title="DataView.prototype.setInt16 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.22</span> DataView.prototype.setInt16 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setint32" title="DataView.prototype.setInt32 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.23</span> DataView.prototype.setInt32 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setuint8" title="DataView.prototype.setUint8 ( byteOffset, value )"><span class="secnum">25.3.4.24</span> DataView.prototype.setUint8 ( <var>byteOffset</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setuint16" title="DataView.prototype.setUint16 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.25</span> DataView.prototype.setUint16 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype.setuint32" title="DataView.prototype.setUint32 ( byteOffset, value [ , littleEndian ] )"><span class="secnum">25.3.4.26</span> DataView.prototype.setUint32 ( <var>byteOffset</var>, <var>value</var> [ , <var>littleEndian</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dataview.prototype-%symbol.tostringtag%" title="DataView.prototype [ %Symbol.toStringTag% ]"><span class="secnum">25.3.4.27</span> DataView.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-properties-of-dataview-instances" title="Properties of DataView Instances"><span class="secnum">25.3.5</span> Properties of DataView Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-atomics-object" title="The Atomics Object"><span class="secnum">25.4</span> The Atomics Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-waiter-record" title="Waiter Record"><span class="secnum">25.4.1</span> Waiter Record</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-waiterlist-records" title="WaiterList Records"><span class="secnum">25.4.2</span> WaiterList Records</a></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-abstract-operations-for-atomics" title="Abstract Operations for Atomics"><span class="secnum">25.4.3</span> Abstract Operations for Atomics</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-validateintegertypedarray" title="ValidateIntegerTypedArray ( typedArray, waitable )"><span class="secnum">25.4.3.1</span> ValidateIntegerTypedArray ( <var>typedArray</var>, <var>waitable</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-validateatomicaccess" title="ValidateAtomicAccess ( taRecord, requestIndex )"><span class="secnum">25.4.3.2</span> ValidateAtomicAccess ( <var>taRecord</var>, <var>requestIndex</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-validateatomicaccessonintegertypedarray" title="ValidateAtomicAccessOnIntegerTypedArray ( typedArray, requestIndex )"><span class="secnum">25.4.3.3</span> ValidateAtomicAccessOnIntegerTypedArray ( <var>typedArray</var>, <var>requestIndex</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-revalidateatomicaccess" title="RevalidateAtomicAccess ( typedArray, byteIndexInBuffer )"><span class="secnum">25.4.3.4</span> RevalidateAtomicAccess ( <var>typedArray</var>, <var>byteIndexInBuffer</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-getwaiterlist" title="GetWaiterList ( block, i )"><span class="secnum">25.4.3.5</span> GetWaiterList ( <var>block</var>, <var>i</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-entercriticalsection" title="EnterCriticalSection ( WL )"><span class="secnum">25.4.3.6</span> EnterCriticalSection ( <var>WL</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-leavecriticalsection" title="LeaveCriticalSection ( WL )"><span class="secnum">25.4.3.7</span> LeaveCriticalSection ( <var>WL</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-addwaiter" title="AddWaiter ( WL, waiterRecord )"><span class="secnum">25.4.3.8</span> AddWaiter ( <var>WL</var>, <var>waiterRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-removewaiter" title="RemoveWaiter ( WL, waiterRecord )"><span class="secnum">25.4.3.9</span> RemoveWaiter ( <var>WL</var>, <var>waiterRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-removewaiters" title="RemoveWaiters ( WL, c )"><span class="secnum">25.4.3.10</span> RemoveWaiters ( <var>WL</var>, <var>c</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-suspendthisagent" title="SuspendThisAgent ( WL, waiterRecord )"><span class="secnum">25.4.3.11</span> SuspendThisAgent ( <var>WL</var>, <var>waiterRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-notifywaiter" title="NotifyWaiter ( WL, waiterRecord )"><span class="secnum">25.4.3.12</span> NotifyWaiter ( <var>WL</var>, <var>waiterRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-enqueueresolveinagentjob" title="EnqueueResolveInAgentJob ( agentSignifier, promiseCapability, resolution )"><span class="secnum">25.4.3.13</span> EnqueueResolveInAgentJob ( <var>agentSignifier</var>, <var>promiseCapability</var>, <var>resolution</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-dowait" title="DoWait ( mode, typedArray, index, value, timeout )"><span class="secnum">25.4.3.14</span> DoWait ( <var>mode</var>, <var>typedArray</var>, <var>index</var>, <var>value</var>, <var>timeout</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-enqueueatomicswaitasynctimeoutjob" title="EnqueueAtomicsWaitAsyncTimeoutJob ( WL, waiterRecord )"><span class="secnum">25.4.3.15</span> EnqueueAtomicsWaitAsyncTimeoutJob ( <var>WL</var>, <var>waiterRecord</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomiccompareexchangeinsharedblock" title="AtomicCompareExchangeInSharedBlock ( block, byteIndexInBuffer, elementSize, expectedBytes, replacementBytes )"><span class="secnum">25.4.3.16</span> AtomicCompareExchangeInSharedBlock ( <var>block</var>, <var>byteIndexInBuffer</var>, <var>elementSize</var>, <var>expectedBytes</var>, <var>replacementBytes</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomicreadmodifywrite" title="AtomicReadModifyWrite ( typedArray, index, value, op )"><span class="secnum">25.4.3.17</span> AtomicReadModifyWrite ( <var>typedArray</var>, <var>index</var>, <var>value</var>, <var>op</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-bytelistbitwiseop" title="ByteListBitwiseOp ( op, xBytes, yBytes )"><span class="secnum">25.4.3.18</span> ByteListBitwiseOp ( <var>op</var>, <var>xBytes</var>, <var>yBytes</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-bytelistequal" title="ByteListEqual ( xBytes, yBytes )"><span class="secnum">25.4.3.19</span> ByteListEqual ( <var>xBytes</var>, <var>yBytes</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.add" title="Atomics.add ( typedArray, index, value )"><span class="secnum">25.4.4</span> Atomics.add ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.and" title="Atomics.and ( typedArray, index, value )"><span class="secnum">25.4.5</span> Atomics.and ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.compareexchange" title="Atomics.compareExchange ( typedArray, index, expectedValue, replacementValue )"><span class="secnum">25.4.6</span> Atomics.compareExchange ( <var>typedArray</var>, <var>index</var>, <var>expectedValue</var>, <var>replacementValue</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.exchange" title="Atomics.exchange ( typedArray, index, value )"><span class="secnum">25.4.7</span> Atomics.exchange ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.islockfree" title="Atomics.isLockFree ( size )"><span class="secnum">25.4.8</span> Atomics.isLockFree ( <var>size</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.load" title="Atomics.load ( typedArray, index )"><span class="secnum">25.4.9</span> Atomics.load ( <var>typedArray</var>, <var>index</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.or" title="Atomics.or ( typedArray, index, value )"><span class="secnum">25.4.10</span> Atomics.or ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.store" title="Atomics.store ( typedArray, index, value )"><span class="secnum">25.4.11</span> Atomics.store ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.sub" title="Atomics.sub ( typedArray, index, value )"><span class="secnum">25.4.12</span> Atomics.sub ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.wait" title="Atomics.wait ( typedArray, index, value, timeout )"><span class="secnum">25.4.13</span> Atomics.wait ( <var>typedArray</var>, <var>index</var>, <var>value</var>, <var>timeout</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.waitasync" title="Atomics.waitAsync ( typedArray, index, value, timeout )"><span class="secnum">25.4.14</span> Atomics.waitAsync ( <var>typedArray</var>, <var>index</var>, <var>value</var>, <var>timeout</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.notify" title="Atomics.notify ( typedArray, index, count )"><span class="secnum">25.4.15</span> Atomics.notify ( <var>typedArray</var>, <var>index</var>, <var>count</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics.xor" title="Atomics.xor ( typedArray, index, value )"><span class="secnum">25.4.16</span> Atomics.xor ( <var>typedArray</var>, <var>index</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-atomics-%symbol.tostringtag%" title="Atomics [ %Symbol.toStringTag% ]"><span class="secnum">25.4.17</span> Atomics [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-json-object" title="The JSON Object"><span class="secnum">25.5</span> The JSON Object</a><ol class="toc"><li><span class="item-toggle">+</span><a href="structured-data.html#sec-json.parse" title="JSON.parse ( text [ , reviver ] )"><span class="secnum">25.5.1</span> JSON.parse ( <var>text</var> [ , <var>reviver</var> ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-ParseJSON" title="ParseJSON ( text )"><span class="secnum">25.5.1.1</span> ParseJSON ( <var>text</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-internalizejsonproperty" title="InternalizeJSONProperty ( holder, name, reviver )"><span class="secnum">25.5.1.2</span> InternalizeJSONProperty ( <var>holder</var>, <var>name</var>, <var>reviver</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="structured-data.html#sec-json.stringify" title="JSON.stringify ( value [ , replacer [ , space ] ] )"><span class="secnum">25.5.2</span> JSON.stringify ( <var>value</var> [ , <var>replacer</var> [ , <var>space</var> ] ] )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-json-serialization-record" title="JSON Serialization Record"><span class="secnum">25.5.2.1</span> JSON Serialization Record</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-serializejsonproperty" title="SerializeJSONProperty ( state, key, holder )"><span class="secnum">25.5.2.2</span> SerializeJSONProperty ( <var>state</var>, <var>key</var>, <var>holder</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-quotejsonstring" title="QuoteJSONString ( value )"><span class="secnum">25.5.2.3</span> QuoteJSONString ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-unicodeescape" title="UnicodeEscape ( C )"><span class="secnum">25.5.2.4</span> UnicodeEscape ( <var>C</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-serializejsonobject" title="SerializeJSONObject ( state, value )"><span class="secnum">25.5.2.5</span> SerializeJSONObject ( <var>state</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-serializejsonarray" title="SerializeJSONArray ( state, value )"><span class="secnum">25.5.2.6</span> SerializeJSONArray ( <var>state</var>, <var>value</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="structured-data.html#sec-json-%symbol.tostringtag%" title="JSON [ %Symbol.toStringTag% ]"><span class="secnum">25.5.3</span> JSON [ %Symbol.toStringTag% ]</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-managing-memory" title="Managing Memory"><span class="secnum">26</span> Managing Memory</a><ol class="toc"><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-weak-ref-objects" title="WeakRef Objects"><span class="secnum">26.1</span> WeakRef Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-weak-ref-constructor" title="The WeakRef Constructor"><span class="secnum">26.1.1</span> The WeakRef Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-weak-ref-target" title="WeakRef ( target )"><span class="secnum">26.1.1.1</span> WeakRef ( <var>target</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-properties-of-the-weak-ref-constructor" title="Properties of the WeakRef Constructor"><span class="secnum">26.1.2</span> Properties of the WeakRef Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-weak-ref.prototype" title="WeakRef.prototype"><span class="secnum">26.1.2.1</span> WeakRef.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-properties-of-the-weak-ref-prototype-object" title="Properties of the WeakRef Prototype Object"><span class="secnum">26.1.3</span> Properties of the WeakRef Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-weak-ref.prototype.constructor" title="WeakRef.prototype.constructor"><span class="secnum">26.1.3.1</span> WeakRef.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-weak-ref.prototype.deref" title="WeakRef.prototype.deref ( )"><span class="secnum">26.1.3.2</span> WeakRef.prototype.deref ( )</a></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-weak-ref.prototype-%symbol.tostringtag%" title="WeakRef.prototype [ %Symbol.toStringTag% ]"><span class="secnum">26.1.3.3</span> WeakRef.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-weakref-abstract-operations" title="WeakRef Abstract Operations"><span class="secnum">26.1.4</span> WeakRef Abstract Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-weakrefderef" title="WeakRefDeref ( weakRef )"><span class="secnum">26.1.4.1</span> WeakRefDeref ( <var>weakRef</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-properties-of-weak-ref-instances" title="Properties of WeakRef Instances"><span class="secnum">26.1.5</span> Properties of WeakRef Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-finalization-registry-objects" title="FinalizationRegistry Objects"><span class="secnum">26.2</span> FinalizationRegistry Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-finalization-registry-constructor" title="The FinalizationRegistry Constructor"><span class="secnum">26.2.1</span> The FinalizationRegistry Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-finalization-registry-cleanup-callback" title="FinalizationRegistry ( cleanupCallback )"><span class="secnum">26.2.1.1</span> FinalizationRegistry ( <var>cleanupCallback</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-properties-of-the-finalization-registry-constructor" title="Properties of the FinalizationRegistry Constructor"><span class="secnum">26.2.2</span> Properties of the FinalizationRegistry Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-finalization-registry.prototype" title="FinalizationRegistry.prototype"><span class="secnum">26.2.2.1</span> FinalizationRegistry.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="managing-memory.html#sec-properties-of-the-finalization-registry-prototype-object" title="Properties of the FinalizationRegistry Prototype Object"><span class="secnum">26.2.3</span> Properties of the FinalizationRegistry Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-finalization-registry.prototype.constructor" title="FinalizationRegistry.prototype.constructor"><span class="secnum">26.2.3.1</span> FinalizationRegistry.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-finalization-registry.prototype.register" title="FinalizationRegistry.prototype.register ( target, heldValue [ , unregisterToken ] )"><span class="secnum">26.2.3.2</span> FinalizationRegistry.prototype.register ( <var>target</var>, <var>heldValue</var> [ , <var>unregisterToken</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-finalization-registry.prototype.unregister" title="FinalizationRegistry.prototype.unregister ( unregisterToken )"><span class="secnum">26.2.3.3</span> FinalizationRegistry.prototype.unregister ( <var>unregisterToken</var> )</a></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-finalization-registry.prototype-%symbol.tostringtag%" title="FinalizationRegistry.prototype [ %Symbol.toStringTag% ]"><span class="secnum">26.2.3.4</span> FinalizationRegistry.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="managing-memory.html#sec-properties-of-finalization-registry-instances" title="Properties of FinalizationRegistry Instances"><span class="secnum">26.2.4</span> Properties of FinalizationRegistry Instances</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-control-abstraction-objects" title="Control Abstraction Objects"><span class="secnum">27</span> Control Abstraction Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iteration" title="Iteration"><span class="secnum">27.1</span> Iteration</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-common-iteration-interfaces" title="Common Iteration Interfaces"><span class="secnum">27.1.1</span> Common Iteration Interfaces</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterable-interface" title="The Iterable Interface"><span class="secnum">27.1.1.1</span> The Iterable Interface</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator-interface" title="The Iterator Interface"><span class="secnum">27.1.1.2</span> The Iterator Interface</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asynciterable-interface" title="The Async Iterable Interface"><span class="secnum">27.1.1.3</span> The Async Iterable Interface</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asynciterator-interface" title="The Async Iterator Interface"><span class="secnum">27.1.1.4</span> The Async Iterator Interface</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iteratorresult-interface" title="The IteratorResult Interface"><span class="secnum">27.1.1.5</span> The IteratorResult Interface</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iterator-helper-objects" title="Iterator Helper Objects"><span class="secnum">27.1.2</span> Iterator Helper Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object" title="The %IteratorHelperPrototype% Object"><span class="secnum">27.1.2.1</span> The %IteratorHelperPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%.next" title="%IteratorHelperPrototype%.next ( )"><span class="secnum">27.1.2.1.1</span> %IteratorHelperPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%.return" title="%IteratorHelperPrototype%.return ( )"><span class="secnum">27.1.2.1.2</span> %IteratorHelperPrototype%.return ( )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-%symbol.tostringtag%" title="%IteratorHelperPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">27.1.2.1.3</span> %IteratorHelperPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iterator-objects" title="Iterator Objects"><span class="secnum">27.1.3</span> Iterator Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iterator-constructor" title="The Iterator Constructor"><span class="secnum">27.1.3.1</span> The Iterator Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator" title="Iterator ( )"><span class="secnum">27.1.3.1.1</span> Iterator ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-the-iterator-constructor" title="Properties of the Iterator Constructor"><span class="secnum">27.1.3.2</span> Properties of the Iterator Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.concat" title="Iterator.concat ( ...items )"><span class="secnum">27.1.3.2.1</span> Iterator.concat ( ...<var>items</var> )</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iterator.from" title="Iterator.from ( O )"><span class="secnum">27.1.3.2.2</span> Iterator.from ( <var>O</var> )</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-%wrapforvaliditeratorprototype%-object" title="The %WrapForValidIteratorPrototype% Object"><span class="secnum">27.1.3.2.2.1</span> The %WrapForValidIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%wrapforvaliditeratorprototype%.next" title="%WrapForValidIteratorPrototype%.next ( )"><span class="secnum">27.1.3.2.2.1.1</span> %WrapForValidIteratorPrototype%.next ( )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%wrapforvaliditeratorprototype%.return" title="%WrapForValidIteratorPrototype%.return ( )"><span class="secnum">27.1.3.2.2.1.2</span> %WrapForValidIteratorPrototype%.return ( )</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype" title="Iterator.prototype"><span class="secnum">27.1.3.2.3</span> Iterator.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object" title="Properties of the Iterator Prototype Object"><span class="secnum">27.1.3.3</span> Properties of the Iterator Prototype Object</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iterator.prototype.constructor" title="Iterator.prototype.constructor"><span class="secnum">27.1.3.3.1</span> Iterator.prototype.constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-get-iterator.prototype.constructor" title="get Iterator.prototype.constructor"><span class="secnum">27.1.3.3.1.1</span> get Iterator.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-set-iterator.prototype.constructor" title="set Iterator.prototype.constructor"><span class="secnum">27.1.3.3.1.2</span> set Iterator.prototype.constructor</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.drop" title="Iterator.prototype.drop ( limit )"><span class="secnum">27.1.3.3.2</span> Iterator.prototype.drop ( <var>limit</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.every" title="Iterator.prototype.every ( predicate )"><span class="secnum">27.1.3.3.3</span> Iterator.prototype.every ( <var>predicate</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.filter" title="Iterator.prototype.filter ( predicate )"><span class="secnum">27.1.3.3.4</span> Iterator.prototype.filter ( <var>predicate</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.find" title="Iterator.prototype.find ( predicate )"><span class="secnum">27.1.3.3.5</span> Iterator.prototype.find ( <var>predicate</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.flatmap" title="Iterator.prototype.flatMap ( mapper )"><span class="secnum">27.1.3.3.6</span> Iterator.prototype.flatMap ( <var>mapper</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.foreach" title="Iterator.prototype.forEach ( procedure )"><span class="secnum">27.1.3.3.7</span> Iterator.prototype.forEach ( <var>procedure</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.map" title="Iterator.prototype.map ( mapper )"><span class="secnum">27.1.3.3.8</span> Iterator.prototype.map ( <var>mapper</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.reduce" title="Iterator.prototype.reduce ( reducer [ , initialValue ] )"><span class="secnum">27.1.3.3.9</span> Iterator.prototype.reduce ( <var>reducer</var> [ , <var>initialValue</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.some" title="Iterator.prototype.some ( predicate )"><span class="secnum">27.1.3.3.10</span> Iterator.prototype.some ( <var>predicate</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.take" title="Iterator.prototype.take ( limit )"><span class="secnum">27.1.3.3.11</span> Iterator.prototype.take ( <var>limit</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype.toarray" title="Iterator.prototype.toArray ( )"><span class="secnum">27.1.3.3.12</span> Iterator.prototype.toArray ( )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-iterator.prototype-%symbol.iterator%" title="Iterator.prototype [ %Symbol.iterator% ] ( )"><span class="secnum">27.1.3.3.13</span> Iterator.prototype [ %Symbol.iterator% ] ( )</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-iterator.prototype-%symbol.tostringtag%" title="Iterator.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.1.3.3.14</span> Iterator.prototype [ %Symbol.toStringTag% ]</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-get-iterator.prototype-%symbol.tostringtag%" title="get Iterator.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.1.3.3.14.1</span> get Iterator.prototype [ %Symbol.toStringTag% ]</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-set-iterator.prototype-%symbol.tostringtag%" title="set Iterator.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.1.3.3.14.2</span> set Iterator.prototype [ %Symbol.toStringTag% ]</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-asynciteratorprototype" title="The %AsyncIteratorPrototype% Object"><span class="secnum">27.1.4</span> The %AsyncIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%asynciteratorprototype%-%symbol.asynciterator%" title="%AsyncIteratorPrototype% [ %Symbol.asyncIterator% ] ( )"><span class="secnum">27.1.4.1</span> %AsyncIteratorPrototype% [ %Symbol.asyncIterator% ] ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-from-sync-iterator-objects" title="Async-from-Sync Iterator Objects"><span class="secnum">27.1.5</span> Async-from-Sync Iterator Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-createasyncfromsynciterator" title="CreateAsyncFromSyncIterator ( syncIteratorRecord )"><span class="secnum">27.1.5.1</span> CreateAsyncFromSyncIterator ( <var>syncIteratorRecord</var> )</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%-object" title="The %AsyncFromSyncIteratorPrototype% Object"><span class="secnum">27.1.5.2</span> The %AsyncFromSyncIteratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%.next" title="%AsyncFromSyncIteratorPrototype%.next ( [ value ] )"><span class="secnum">27.1.5.2.1</span> %AsyncFromSyncIteratorPrototype%.next ( [ <var>value</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%.return" title="%AsyncFromSyncIteratorPrototype%.return ( [ value ] )"><span class="secnum">27.1.5.2.2</span> %AsyncFromSyncIteratorPrototype%.return ( [ <var>value</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%.throw" title="%AsyncFromSyncIteratorPrototype%.throw ( [ value ] )"><span class="secnum">27.1.5.2.3</span> %AsyncFromSyncIteratorPrototype%.throw ( [ <var>value</var> ] )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-properties-of-async-from-sync-iterator-instances" title="Properties of Async-from-Sync Iterator Instances"><span class="secnum">27.1.5.3</span> Properties of Async-from-Sync Iterator Instances</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncfromsynciteratorcontinuation" title="AsyncFromSyncIteratorContinuation ( result, promiseCapability, syncIteratorRecord, closeOnRejection )"><span class="secnum">27.1.5.4</span> AsyncFromSyncIteratorContinuation ( <var>result</var>, <var>promiseCapability</var>, <var>syncIteratorRecord</var>, <var>closeOnRejection</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise-objects" title="Promise Objects"><span class="secnum">27.2</span> Promise Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise-abstract-operations" title="Promise Abstract Operations"><span class="secnum">27.2.1</span> Promise Abstract Operations</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promisecapability-records" title="PromiseCapability Records"><span class="secnum">27.2.1.1</span> PromiseCapability Records</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" title="IfAbruptRejectPromise ( value, capability )"><span class="secnum">27.2.1.1.1</span> IfAbruptRejectPromise ( <var>value</var>, <var>capability</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promisereaction-records" title="PromiseReaction Records"><span class="secnum">27.2.1.2</span> PromiseReaction Records</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-createresolvingfunctions" title="CreateResolvingFunctions ( toResolve )"><span class="secnum">27.2.1.3</span> CreateResolvingFunctions ( <var>toResolve</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-fulfillpromise" title="FulfillPromise ( promise, value )"><span class="secnum">27.2.1.4</span> FulfillPromise ( <var>promise</var>, <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-newpromisecapability" title="NewPromiseCapability ( C )"><span class="secnum">27.2.1.5</span> NewPromiseCapability ( <var>C</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-ispromise" title="IsPromise ( x )"><span class="secnum">27.2.1.6</span> IsPromise ( <var>x</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-rejectpromise" title="RejectPromise ( promise, reason )"><span class="secnum">27.2.1.7</span> RejectPromise ( <var>promise</var>, <var>reason</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-triggerpromisereactions" title="TriggerPromiseReactions ( reactions, argument )"><span class="secnum">27.2.1.8</span> TriggerPromiseReactions ( <var>reactions</var>, <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-host-promise-rejection-tracker" title="HostPromiseRejectionTracker ( promise, operation )"><span class="secnum">27.2.1.9</span> HostPromiseRejectionTracker ( <var>promise</var>, <var>operation</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise-jobs" title="Promise Jobs"><span class="secnum">27.2.2</span> Promise Jobs</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-newpromisereactionjob" title="NewPromiseReactionJob ( reaction, argument )"><span class="secnum">27.2.2.1</span> NewPromiseReactionJob ( <var>reaction</var>, <var>argument</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-newpromiseresolvethenablejob" title="NewPromiseResolveThenableJob ( promiseToResolve, thenable, then )"><span class="secnum">27.2.2.2</span> NewPromiseResolveThenableJob ( <var>promiseToResolve</var>, <var>thenable</var>, <var>then</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise-constructor" title="The Promise Constructor"><span class="secnum">27.2.3</span> The Promise Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise-executor" title="Promise ( executor )"><span class="secnum">27.2.3.1</span> Promise ( <var>executor</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-the-promise-constructor" title="Properties of the Promise Constructor"><span class="secnum">27.2.4</span> Properties of the Promise Constructor</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise.all" title="Promise.all ( iterable )"><span class="secnum">27.2.4.1</span> Promise.all ( <var>iterable</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-getpromiseresolve" title="GetPromiseResolve ( promiseConstructor )"><span class="secnum">27.2.4.1.1</span> GetPromiseResolve ( <var>promiseConstructor</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-performpromiseall" title="PerformPromiseAll ( iteratorRecord, constructor, resultCapability, promiseResolve )"><span class="secnum">27.2.4.1.2</span> PerformPromiseAll ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise.allsettled" title="Promise.allSettled ( iterable )"><span class="secnum">27.2.4.2</span> Promise.allSettled ( <var>iterable</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-performpromiseallsettled" title="PerformPromiseAllSettled ( iteratorRecord, constructor, resultCapability, promiseResolve )"><span class="secnum">27.2.4.2.1</span> PerformPromiseAllSettled ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise.any" title="Promise.any ( iterable )"><span class="secnum">27.2.4.3</span> Promise.any ( <var>iterable</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-performpromiseany" title="PerformPromiseAny ( iteratorRecord, constructor, resultCapability, promiseResolve )"><span class="secnum">27.2.4.3.1</span> PerformPromiseAny ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.prototype" title="Promise.prototype"><span class="secnum">27.2.4.4</span> Promise.prototype</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise.race" title="Promise.race ( iterable )"><span class="secnum">27.2.4.5</span> Promise.race ( <var>iterable</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-performpromiserace" title="PerformPromiseRace ( iteratorRecord, constructor, resultCapability, promiseResolve )"><span class="secnum">27.2.4.5.1</span> PerformPromiseRace ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.reject" title="Promise.reject ( r )"><span class="secnum">27.2.4.6</span> Promise.reject ( <var>r</var> )</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise.resolve" title="Promise.resolve ( x )"><span class="secnum">27.2.4.7</span> Promise.resolve ( <var>x</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise-resolve" title="PromiseResolve ( C, x )"><span class="secnum">27.2.4.7.1</span> PromiseResolve ( <var>C</var>, <var>x</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.try" title="Promise.try ( callback, ...args )"><span class="secnum">27.2.4.8</span> Promise.try ( <var>callback</var>, ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.withResolvers" title="Promise.withResolvers ( )"><span class="secnum">27.2.4.9</span> Promise.withResolvers ( )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-get-promise-%symbol.species%" title="get Promise [ %Symbol.species% ]"><span class="secnum">27.2.4.10</span> get Promise [ %Symbol.species% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-the-promise-prototype-object" title="Properties of the Promise Prototype Object"><span class="secnum">27.2.5</span> Properties of the Promise Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.prototype.catch" title="Promise.prototype.catch ( onRejected )"><span class="secnum">27.2.5.1</span> Promise.prototype.catch ( <var>onRejected</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.prototype.constructor" title="Promise.prototype.constructor"><span class="secnum">27.2.5.2</span> Promise.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.prototype.finally" title="Promise.prototype.finally ( onFinally )"><span class="secnum">27.2.5.3</span> Promise.prototype.finally ( <var>onFinally</var> )</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-promise.prototype.then" title="Promise.prototype.then ( onFulfilled, onRejected )"><span class="secnum">27.2.5.4</span> Promise.prototype.then ( <var>onFulfilled</var>, <var>onRejected</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-performpromisethen" title="PerformPromiseThen ( promise, onFulfilled, onRejected [ , resultCapability ] )"><span class="secnum">27.2.5.4.1</span> PerformPromiseThen ( <var>promise</var>, <var>onFulfilled</var>, <var>onRejected</var> [ , <var>resultCapability</var> ] )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-promise.prototype-%symbol.tostringtag%" title="Promise.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.2.5.5</span> Promise.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-properties-of-promise-instances" title="Properties of Promise Instances"><span class="secnum">27.2.6</span> Properties of Promise Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-generatorfunction-objects" title="GeneratorFunction Objects"><span class="secnum">27.3</span> GeneratorFunction Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-generatorfunction-constructor" title="The GeneratorFunction Constructor"><span class="secnum">27.3.1</span> The GeneratorFunction Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction" title="GeneratorFunction ( ...parameterArgs, bodyArg )"><span class="secnum">27.3.1.1</span> GeneratorFunction ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-the-generatorfunction-constructor" title="Properties of the GeneratorFunction Constructor"><span class="secnum">27.3.2</span> Properties of the GeneratorFunction Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction.prototype" title="GeneratorFunction.prototype"><span class="secnum">27.3.2.1</span> GeneratorFunction.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-the-generatorfunction-prototype-object" title="Properties of the GeneratorFunction Prototype Object"><span class="secnum">27.3.3</span> Properties of the GeneratorFunction Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction.prototype.constructor" title="GeneratorFunction.prototype.constructor"><span class="secnum">27.3.3.1</span> GeneratorFunction.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction.prototype.prototype" title="GeneratorFunction.prototype.prototype"><span class="secnum">27.3.3.2</span> GeneratorFunction.prototype.prototype</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction.prototype-%symbol.tostringtag%" title="GeneratorFunction.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.3.3.3</span> GeneratorFunction.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-generatorfunction-instances" title="GeneratorFunction Instances"><span class="secnum">27.3.4</span> GeneratorFunction Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction-instances-length" title="length"><span class="secnum">27.3.4.1</span> length</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction-instances-name" title="name"><span class="secnum">27.3.4.2</span> name</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorfunction-instances-prototype" title="prototype"><span class="secnum">27.3.4.3</span> prototype</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-objects" title="AsyncGeneratorFunction Objects"><span class="secnum">27.4</span> AsyncGeneratorFunction Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-constructor" title="The AsyncGeneratorFunction Constructor"><span class="secnum">27.4.1</span> The AsyncGeneratorFunction Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction" title="AsyncGeneratorFunction ( ...parameterArgs, bodyArg )"><span class="secnum">27.4.1.1</span> AsyncGeneratorFunction ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-asyncgeneratorfunction" title="Properties of the AsyncGeneratorFunction Constructor"><span class="secnum">27.4.2</span> Properties of the AsyncGeneratorFunction Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-prototype" title="AsyncGeneratorFunction.prototype"><span class="secnum">27.4.2.1</span> AsyncGeneratorFunction.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-asyncgeneratorfunction-prototype" title="Properties of the AsyncGeneratorFunction Prototype Object"><span class="secnum">27.4.3</span> Properties of the AsyncGeneratorFunction Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-prototype-constructor" title="AsyncGeneratorFunction.prototype.constructor"><span class="secnum">27.4.3.1</span> AsyncGeneratorFunction.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-prototype-prototype" title="AsyncGeneratorFunction.prototype.prototype"><span class="secnum">27.4.3.2</span> AsyncGeneratorFunction.prototype.prototype</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-prototype-%symbol.tostringtag%" title="AsyncGeneratorFunction.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.4.3.3</span> AsyncGeneratorFunction.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-instances" title="AsyncGeneratorFunction Instances"><span class="secnum">27.4.4</span> AsyncGeneratorFunction Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-instance-length" title="length"><span class="secnum">27.4.4.1</span> length</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-instance-name" title="name"><span class="secnum">27.4.4.2</span> name</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-instance-prototype" title="prototype"><span class="secnum">27.4.4.3</span> prototype</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-generator-objects" title="Generator Objects"><span class="secnum">27.5</span> Generator Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-generator-prototype" title="The %GeneratorPrototype% Object"><span class="secnum">27.5.1</span> The %GeneratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generator.prototype.constructor" title="%GeneratorPrototype%.constructor"><span class="secnum">27.5.1.1</span> %GeneratorPrototype%.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generator.prototype.next" title="%GeneratorPrototype%.next ( value )"><span class="secnum">27.5.1.2</span> %GeneratorPrototype%.next ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generator.prototype.return" title="%GeneratorPrototype%.return ( value )"><span class="secnum">27.5.1.3</span> %GeneratorPrototype%.return ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generator.prototype.throw" title="%GeneratorPrototype%.throw ( exception )"><span class="secnum">27.5.1.4</span> %GeneratorPrototype%.throw ( <var>exception</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generator.prototype-%symbol.tostringtag%" title="%GeneratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">27.5.1.5</span> %GeneratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-properties-of-generator-instances" title="Properties of Generator Instances"><span class="secnum">27.5.2</span> Properties of Generator Instances</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-generator-abstract-operations" title="Generator Abstract Operations"><span class="secnum">27.5.3</span> Generator Abstract Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorstart" title="GeneratorStart ( generator, generatorBody )"><span class="secnum">27.5.3.1</span> GeneratorStart ( <var>generator</var>, <var>generatorBody</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorvalidate" title="GeneratorValidate ( generator, generatorBrand )"><span class="secnum">27.5.3.2</span> GeneratorValidate ( <var>generator</var>, <var>generatorBrand</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorresume" title="GeneratorResume ( generator, value, generatorBrand )"><span class="secnum">27.5.3.3</span> GeneratorResume ( <var>generator</var>, <var>value</var>, <var>generatorBrand</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatorresumeabrupt" title="GeneratorResumeAbrupt ( generator, abruptCompletion, generatorBrand )"><span class="secnum">27.5.3.4</span> GeneratorResumeAbrupt ( <var>generator</var>, <var>abruptCompletion</var>, <var>generatorBrand</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-getgeneratorkind" title="GetGeneratorKind ( )"><span class="secnum">27.5.3.5</span> GetGeneratorKind ( )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-generatoryield" title="GeneratorYield ( iteratorResult )"><span class="secnum">27.5.3.6</span> GeneratorYield ( <var>iteratorResult</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-yield" title="Yield ( value )"><span class="secnum">27.5.3.7</span> Yield ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-createiteratorfromclosure" title="CreateIteratorFromClosure ( closure, generatorBrand, generatorPrototype [ , extraSlots ] )"><span class="secnum">27.5.3.8</span> CreateIteratorFromClosure ( <var>closure</var>, <var>generatorBrand</var>, <var>generatorPrototype</var> [ , <var>extraSlots</var> ] )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-asyncgenerator-objects" title="AsyncGenerator Objects"><span class="secnum">27.6</span> AsyncGenerator Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-properties-of-asyncgenerator-prototype" title="The %AsyncGeneratorPrototype% Object"><span class="secnum">27.6.1</span> The %AsyncGeneratorPrototype% Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgenerator-prototype-constructor" title="%AsyncGeneratorPrototype%.constructor"><span class="secnum">27.6.1.1</span> %AsyncGeneratorPrototype%.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgenerator-prototype-next" title="%AsyncGeneratorPrototype%.next ( value )"><span class="secnum">27.6.1.2</span> %AsyncGeneratorPrototype%.next ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgenerator-prototype-return" title="%AsyncGeneratorPrototype%.return ( value )"><span class="secnum">27.6.1.3</span> %AsyncGeneratorPrototype%.return ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgenerator-prototype-throw" title="%AsyncGeneratorPrototype%.throw ( exception )"><span class="secnum">27.6.1.4</span> %AsyncGeneratorPrototype%.throw ( <var>exception</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgenerator-prototype-%symbol.tostringtag%" title="%AsyncGeneratorPrototype% [ %Symbol.toStringTag% ]"><span class="secnum">27.6.1.5</span> %AsyncGeneratorPrototype% [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-properties-of-asyncgenerator-intances" title="Properties of AsyncGenerator Instances"><span class="secnum">27.6.2</span> Properties of AsyncGenerator Instances</a></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-asyncgenerator-abstract-operations" title="AsyncGenerator Abstract Operations"><span class="secnum">27.6.3</span> AsyncGenerator Abstract Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorrequest-records" title="AsyncGeneratorRequest Records"><span class="secnum">27.6.3.1</span> AsyncGeneratorRequest Records</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorstart" title="AsyncGeneratorStart ( generator, generatorBody )"><span class="secnum">27.6.3.2</span> AsyncGeneratorStart ( <var>generator</var>, <var>generatorBody</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorvalidate" title="AsyncGeneratorValidate ( generator, generatorBrand )"><span class="secnum">27.6.3.3</span> AsyncGeneratorValidate ( <var>generator</var>, <var>generatorBrand</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorenqueue" title="AsyncGeneratorEnqueue ( generator, completion, promiseCapability )"><span class="secnum">27.6.3.4</span> AsyncGeneratorEnqueue ( <var>generator</var>, <var>completion</var>, <var>promiseCapability</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" title="AsyncGeneratorCompleteStep ( generator, completion, done [ , realm ] )"><span class="secnum">27.6.3.5</span> AsyncGeneratorCompleteStep ( <var>generator</var>, <var>completion</var>, <var>done</var> [ , <var>realm</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorresume" title="AsyncGeneratorResume ( generator, completion )"><span class="secnum">27.6.3.6</span> AsyncGeneratorResume ( <var>generator</var>, <var>completion</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorunwrapyieldresumption" title="AsyncGeneratorUnwrapYieldResumption ( resumptionValue )"><span class="secnum">27.6.3.7</span> AsyncGeneratorUnwrapYieldResumption ( <var>resumptionValue</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratoryield" title="AsyncGeneratorYield ( value )"><span class="secnum">27.6.3.8</span> AsyncGeneratorYield ( <var>value</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratorawaitreturn" title="AsyncGeneratorAwaitReturn ( generator )"><span class="secnum">27.6.3.9</span> AsyncGeneratorAwaitReturn ( <var>generator</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncgeneratordrainqueue" title="AsyncGeneratorDrainQueue ( generator )"><span class="secnum">27.6.3.10</span> AsyncGeneratorDrainQueue ( <var>generator</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-function-objects" title="AsyncFunction Objects"><span class="secnum">27.7</span> AsyncFunction Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-function-constructor" title="The AsyncFunction Constructor"><span class="secnum">27.7.1</span> The AsyncFunction Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-function-constructor-arguments" title="AsyncFunction ( ...parameterArgs, bodyArg )"><span class="secnum">27.7.1.1</span> AsyncFunction ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-function-constructor-properties" title="Properties of the AsyncFunction Constructor"><span class="secnum">27.7.2</span> Properties of the AsyncFunction Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-function-constructor-prototype" title="AsyncFunction.prototype"><span class="secnum">27.7.2.1</span> AsyncFunction.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-function-prototype-properties" title="Properties of the AsyncFunction Prototype Object"><span class="secnum">27.7.3</span> Properties of the AsyncFunction Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-function-prototype-properties-constructor" title="AsyncFunction.prototype.constructor"><span class="secnum">27.7.3.1</span> AsyncFunction.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-function-prototype-%symbol.tostringtag%" title="AsyncFunction.prototype [ %Symbol.toStringTag% ]"><span class="secnum">27.7.3.2</span> AsyncFunction.prototype [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-function-instances" title="AsyncFunction Instances"><span class="secnum">27.7.4</span> AsyncFunction Instances</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-function-instances-length" title="length"><span class="secnum">27.7.4.1</span> length</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-function-instances-name" title="name"><span class="secnum">27.7.4.2</span> name</a></li></ol></li><li><span class="item-toggle">+</span><a href="control-abstraction-objects.html#sec-async-functions-abstract-operations" title="Async Functions Abstract Operations"><span class="secnum">27.7.5</span> Async Functions Abstract Operations</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-async-functions-abstract-operations-async-function-start" title="AsyncFunctionStart ( promiseCapability, asyncFunctionBody )"><span class="secnum">27.7.5.1</span> AsyncFunctionStart ( <var>promiseCapability</var>, <var>asyncFunctionBody</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#sec-asyncblockstart" title="AsyncBlockStart ( promiseCapability, asyncBody, asyncContext )"><span class="secnum">27.7.5.2</span> AsyncBlockStart ( <var>promiseCapability</var>, <var>asyncBody</var>, <var>asyncContext</var> )</a></li><li><span class="item-toggle-none"></span><a href="control-abstraction-objects.html#await" title="Await ( value )"><span class="secnum">27.7.5.3</span> Await ( <var>value</var> )</a></li></ol></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="reflection.html#sec-reflection" title="Reflection"><span class="secnum">28</span> Reflection</a><ol class="toc"><li><span class="item-toggle">+</span><a href="reflection.html#sec-reflect-object" title="The Reflect Object"><span class="secnum">28.1</span> The Reflect Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.apply" title="Reflect.apply ( target, thisArgument, argumentsList )"><span class="secnum">28.1.1</span> Reflect.apply ( <var>target</var>, <var>thisArgument</var>, <var>argumentsList</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.construct" title="Reflect.construct ( target, argumentsList [ , newTarget ] )"><span class="secnum">28.1.2</span> Reflect.construct ( <var>target</var>, <var>argumentsList</var> [ , <var>newTarget</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.defineproperty" title="Reflect.defineProperty ( target, propertyKey, attributes )"><span class="secnum">28.1.3</span> Reflect.defineProperty ( <var>target</var>, <var>propertyKey</var>, <var>attributes</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.deleteproperty" title="Reflect.deleteProperty ( target, propertyKey )"><span class="secnum">28.1.4</span> Reflect.deleteProperty ( <var>target</var>, <var>propertyKey</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.get" title="Reflect.get ( target, propertyKey [ , receiver ] )"><span class="secnum">28.1.5</span> Reflect.get ( <var>target</var>, <var>propertyKey</var> [ , <var>receiver</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.getownpropertydescriptor" title="Reflect.getOwnPropertyDescriptor ( target, propertyKey )"><span class="secnum">28.1.6</span> Reflect.getOwnPropertyDescriptor ( <var>target</var>, <var>propertyKey</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.getprototypeof" title="Reflect.getPrototypeOf ( target )"><span class="secnum">28.1.7</span> Reflect.getPrototypeOf ( <var>target</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.has" title="Reflect.has ( target, propertyKey )"><span class="secnum">28.1.8</span> Reflect.has ( <var>target</var>, <var>propertyKey</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.isextensible" title="Reflect.isExtensible ( target )"><span class="secnum">28.1.9</span> Reflect.isExtensible ( <var>target</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.ownkeys" title="Reflect.ownKeys ( target )"><span class="secnum">28.1.10</span> Reflect.ownKeys ( <var>target</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.preventextensions" title="Reflect.preventExtensions ( target )"><span class="secnum">28.1.11</span> Reflect.preventExtensions ( <var>target</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.set" title="Reflect.set ( target, propertyKey, V [ , receiver ] )"><span class="secnum">28.1.12</span> Reflect.set ( <var>target</var>, <var>propertyKey</var>, <var>V</var> [ , <var>receiver</var> ] )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect.setprototypeof" title="Reflect.setPrototypeOf ( target, proto )"><span class="secnum">28.1.13</span> Reflect.setPrototypeOf ( <var>target</var>, <var>proto</var> )</a></li><li><span class="item-toggle-none"></span><a href="reflection.html#sec-reflect-%symbol.tostringtag%" title="Reflect [ %Symbol.toStringTag% ]"><span class="secnum">28.1.14</span> Reflect [ %Symbol.toStringTag% ]</a></li></ol></li><li><span class="item-toggle">+</span><a href="reflection.html#sec-proxy-objects" title="Proxy Objects"><span class="secnum">28.2</span> Proxy Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="reflection.html#sec-proxy-constructor" title="The Proxy Constructor"><span class="secnum">28.2.1</span> The Proxy Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="reflection.html#sec-proxy-target-handler" title="Proxy ( target, handler )"><span class="secnum">28.2.1.1</span> Proxy ( <var>target</var>, <var>handler</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="reflection.html#sec-properties-of-the-proxy-constructor" title="Properties of the Proxy Constructor"><span class="secnum">28.2.2</span> Properties of the Proxy Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="reflection.html#sec-proxy.revocable" title="Proxy.revocable ( target, handler )"><span class="secnum">28.2.2.1</span> Proxy.revocable ( <var>target</var>, <var>handler</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="reflection.html#sec-module-namespace-objects" title="Module Namespace Objects"><span class="secnum">28.3</span> Module Namespace Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="reflection.html#sec-%symbol.tostringtag%" title="%Symbol.toStringTag%"><span class="secnum">28.3.1</span> %Symbol.toStringTag%</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="memory-model.html#sec-memory-model" title="Memory Model"><span class="secnum">29</span> Memory Model</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-memory-model-fundamentals" title="Memory Model Fundamentals"><span class="secnum">29.1</span> Memory Model Fundamentals</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-agent-event-records" title="Agent Events Records"><span class="secnum">29.2</span> Agent Events Records</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-chosen-value-records" title="Chosen Value Records"><span class="secnum">29.3</span> Chosen Value Records</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-candidate-executions" title="Candidate Executions"><span class="secnum">29.4</span> Candidate Executions</a></li><li><span class="item-toggle">+</span><a href="memory-model.html#sec-abstract-operations-for-the-memory-model" title="Abstract Operations for the Memory Model"><span class="secnum">29.5</span> Abstract Operations for the Memory Model</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-event-set" title="EventSet ( execution )"><span class="secnum">29.5.1</span> EventSet ( <var>execution</var> )</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-sharedatablockeventset" title="SharedDataBlockEventSet ( execution )"><span class="secnum">29.5.2</span> SharedDataBlockEventSet ( <var>execution</var> )</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-hosteventset" title="HostEventSet ( execution )"><span class="secnum">29.5.3</span> HostEventSet ( <var>execution</var> )</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-composewriteeventbytes" title="ComposeWriteEventBytes ( execution, byteIndex, Ws )"><span class="secnum">29.5.4</span> ComposeWriteEventBytes ( <var>execution</var>, <var>byteIndex</var>, <var>Ws</var> )</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-valueofreadevent" title="ValueOfReadEvent ( execution, R )"><span class="secnum">29.5.5</span> ValueOfReadEvent ( <var>execution</var>, <var>R</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="memory-model.html#sec-relations-of-candidate-executions" title="Relations of Candidate Executions"><span class="secnum">29.6</span> Relations of Candidate Executions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-agent-order" title="is-agent-order-before"><span class="secnum">29.6.1</span> is-agent-order-before</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-reads-bytes-from" title="reads-bytes-from"><span class="secnum">29.6.2</span> reads-bytes-from</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-reads-from" title="reads-from"><span class="secnum">29.6.3</span> reads-from</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-host-synchronizes-with" title="host-synchronizes-with"><span class="secnum">29.6.4</span> host-synchronizes-with</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-synchronizes-with" title="synchronizes-with"><span class="secnum">29.6.5</span> synchronizes-with</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-happens-before" title="happens-before"><span class="secnum">29.6.6</span> happens-before</a></li></ol></li><li><span class="item-toggle">+</span><a href="memory-model.html#sec-properties-of-valid-executions" title="Properties of Valid Executions"><span class="secnum">29.7</span> Properties of Valid Executions</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-valid-chosen-reads" title="Valid Chosen Reads"><span class="secnum">29.7.1</span> Valid Chosen Reads</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-coherent-reads" title="Coherent Reads"><span class="secnum">29.7.2</span> Coherent Reads</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-tear-free-aligned-reads" title="Tear Free Reads"><span class="secnum">29.7.3</span> Tear Free Reads</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-memory-order" title="Sequentially Consistent Atomics"><span class="secnum">29.7.4</span> Sequentially Consistent Atomics</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-valid-executions" title="Valid Executions"><span class="secnum">29.7.5</span> Valid Executions</a></li></ol></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-races" title="Races"><span class="secnum">29.8</span> Races</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-data-races" title="Data Races"><span class="secnum">29.9</span> Data Races</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-data-race-freedom" title="Data Race Freedom"><span class="secnum">29.10</span> Data Race Freedom</a></li><li><span class="item-toggle-none"></span><a href="memory-model.html#sec-shared-memory-guidelines" title="Shared Memory Guidelines"><span class="secnum">29.11</span> Shared Memory Guidelines</a></li></ol></li><li><span class="item-toggle">+</span><a href="grammar-summary.html#sec-grammar-summary" title="Grammar Summary"><span class="secnum">Annex A <span class="annex-kind">(informative)</span></span> Grammar Summary</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-lexical-grammar" title="Lexical Grammar"><span class="secnum">A.1</span> Lexical Grammar</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-expressions" title="Expressions"><span class="secnum">A.2</span> Expressions</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-statements" title="Statements"><span class="secnum">A.3</span> Statements</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-functions-and-classes" title="Functions and Classes"><span class="secnum">A.4</span> Functions and Classes</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-scripts-and-modules" title="Scripts and Modules"><span class="secnum">A.5</span> Scripts and Modules</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-number-conversions" title="Number Conversions"><span class="secnum">A.6</span> Number Conversions</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-time-zone-offset-string-format" title="Time Zone Offset String Format"><span class="secnum">A.7</span> Time Zone Offset String Format</a></li><li><span class="item-toggle-none"></span><a href="grammar-summary.html#sec-regular-expressions" title="Regular Expressions"><span class="secnum">A.8</span> Regular Expressions</a></li></ol></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-ecmascript-features-for-web-browsers" title="Additional ECMAScript Features for Web Browsers"><span class="secnum">Annex B <span class="annex-kind">(normative)</span></span> Additional ECMAScript Features for Web Browsers</a><ol class="toc"><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-syntax" title="Additional Syntax"><span class="secnum">B.1</span> Additional Syntax</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-html-like-comments" title="HTML-like Comments"><span class="secnum">B.1.1</span> HTML-like Comments</a></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-regular-expressions-patterns" title="Regular Expressions Patterns"><span class="secnum">B.1.2</span> Regular Expressions Patterns</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-patterns-static-semantics-early-errors-annexb" title="Static Semantics: Early Errors"><span class="secnum">B.1.2.1</span> SS: Early Errors</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-countleftcapturingparens-annexb" title="Static Semantics: CountLeftCapturingParensWithin and CountLeftCapturingParensBefore"><span class="secnum">B.1.2.2</span> SS: CountLeftCapturingParensWithin and CountLeftCapturingParensBefore</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-patterns-static-semantics-is-character-class-annexb" title="Static Semantics: IsCharacterClass"><span class="secnum">B.1.2.3</span> SS: IsCharacterClass</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-patterns-static-semantics-character-value-annexb" title="Static Semantics: CharacterValue"><span class="secnum">B.1.2.4</span> SS: CharacterValue</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-compilesubpattern-annexb" title="Runtime Semantics: CompileSubpattern"><span class="secnum">B.1.2.5</span> RS: CompileSubpattern</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-compileassertion-annexb" title="Runtime Semantics: CompileAssertion"><span class="secnum">B.1.2.6</span> RS: CompileAssertion</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-compileatom-annexb" title="Runtime Semantics: CompileAtom"><span class="secnum">B.1.2.7</span> RS: CompileAtom</a></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-compiletocharset-annexb" title="Runtime Semantics: CompileToCharSet"><span class="secnum">B.1.2.8</span> RS: CompileToCharSet</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-runtime-semantics-characterrangeorunion-abstract-operation" title="CharacterRangeOrUnion ( rer, A, B )"><span class="secnum">B.1.2.8.1</span> CharacterRangeOrUnion ( <var>rer</var>, <var>A</var>, <var>B</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-parsepattern-annexb" title="Static Semantics: ParsePattern ( patternText, u, v )"><span class="secnum">B.1.2.9</span> SS: ParsePattern ( <var>patternText</var>, <var>u</var>, <var>v</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-built-in-properties" title="Additional Built-in Properties"><span class="secnum">B.2</span> Additional Built-in Properties</a><ol class="toc"><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-properties-of-the-global-object" title="Additional Properties of the Global Object"><span class="secnum">B.2.1</span> Additional Properties of the Global Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-escape-string" title="escape ( string )"><span class="secnum">B.2.1.1</span> escape ( <var>string</var> )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-unescape-string" title="unescape ( string )"><span class="secnum">B.2.1.2</span> unescape ( <var>string</var> )</a></li></ol></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-properties-of-the-string.prototype-object" title="Additional Properties of the String.prototype Object"><span class="secnum">B.2.2</span> Additional Properties of the String.prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.substr" title="String.prototype.substr ( start, length )"><span class="secnum">B.2.2.1</span> String.prototype.substr ( <var>start</var>, <var>length</var> )</a></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.anchor" title="String.prototype.anchor ( name )"><span class="secnum">B.2.2.2</span> String.prototype.anchor ( <var>name</var> )</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-createhtml" title="CreateHTML ( string, tag, attribute, value )"><span class="secnum">B.2.2.2.1</span> CreateHTML ( <var>string</var>, <var>tag</var>, <var>attribute</var>, <var>value</var> )</a></li></ol></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.big" title="String.prototype.big ( )"><span class="secnum">B.2.2.3</span> String.prototype.big ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.blink" title="String.prototype.blink ( )"><span class="secnum">B.2.2.4</span> String.prototype.blink ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.bold" title="String.prototype.bold ( )"><span class="secnum">B.2.2.5</span> String.prototype.bold ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.fixed" title="String.prototype.fixed ( )"><span class="secnum">B.2.2.6</span> String.prototype.fixed ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.fontcolor" title="String.prototype.fontcolor ( colour )"><span class="secnum">B.2.2.7</span> String.prototype.fontcolor ( <var>colour</var> )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.fontsize" title="String.prototype.fontsize ( size )"><span class="secnum">B.2.2.8</span> String.prototype.fontsize ( <var>size</var> )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.italics" title="String.prototype.italics ( )"><span class="secnum">B.2.2.9</span> String.prototype.italics ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.link" title="String.prototype.link ( url )"><span class="secnum">B.2.2.10</span> String.prototype.link ( <var>url</var> )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.small" title="String.prototype.small ( )"><span class="secnum">B.2.2.11</span> String.prototype.small ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.strike" title="String.prototype.strike ( )"><span class="secnum">B.2.2.12</span> String.prototype.strike ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.sub" title="String.prototype.sub ( )"><span class="secnum">B.2.2.13</span> String.prototype.sub ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-string.prototype.sup" title="String.prototype.sup ( )"><span class="secnum">B.2.2.14</span> String.prototype.sup ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#String.prototype.trimleft" title="String.prototype.trimLeft ( )"><span class="secnum">B.2.2.15</span> String.prototype.trimLeft ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#String.prototype.trimright" title="String.prototype.trimRight ( )"><span class="secnum">B.2.2.16</span> String.prototype.trimRight ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-properties-of-the-date.prototype-object" title="Additional Properties of the Date.prototype Object"><span class="secnum">B.2.3</span> Additional Properties of the Date.prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-date.prototype.getyear" title="Date.prototype.getYear ( )"><span class="secnum">B.2.3.1</span> Date.prototype.getYear ( )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-date.prototype.setyear" title="Date.prototype.setYear ( year )"><span class="secnum">B.2.3.2</span> Date.prototype.setYear ( <var>year</var> )</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-date.prototype.togmtstring" title="Date.prototype.toGMTString ( )"><span class="secnum">B.2.3.3</span> Date.prototype.toGMTString ( )</a></li></ol></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-additional-properties-of-the-regexp.prototype-object" title="Additional Properties of the RegExp.prototype Object"><span class="secnum">B.2.4</span> Additional Properties of the RegExp.prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-regexp.prototype.compile" title="RegExp.prototype.compile ( pattern, flags )"><span class="secnum">B.2.4.1</span> RegExp.prototype.compile ( <var>pattern</var>, <var>flags</var> )</a></li></ol></li></ol></li><li><span class="item-toggle">+</span><a href="additional-ecmascript-features-for-web-browsers.html#sec-other-additional-features" title="Other Additional Features"><span class="secnum">B.3</span> Other Additional Features</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations" title="Labelled Function Declarations"><span class="secnum">B.3.1</span> Labelled Function Declarations</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-block-level-function-declarations-web-legacy-compatibility-semantics" title="Block-Level Function Declarations Web Legacy Compatibility Semantics"><span class="secnum">B.3.2</span> Block-Level Function Declarations Web Legacy Compatibility Semantics</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-functiondeclarations-in-ifstatement-statement-clauses" title="FunctionDeclarations in IfStatement Statement Clauses"><span class="secnum">B.3.3</span> FunctionDeclarations in IfStatement Statement Clauses</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-variablestatements-in-catch-blocks" title="VariableStatements in Catch Blocks"><span class="secnum">B.3.4</span> VariableStatements in Catch Blocks</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-initializers-in-forin-statement-heads" title="Initializers in ForIn Statement Heads"><span class="secnum">B.3.5</span> Initializers in ForIn Statement Heads</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-IsHTMLDDA-internal-slot" title="The [[IsHTMLDDA]] Internal Slot"><span class="secnum">B.3.6</span> The <var class="field">[[IsHTMLDDA]]</var> Internal Slot</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-web-compat-host-make-job-callback" title="Non-default behaviour in HostMakeJobCallback"><span class="secnum">B.3.7</span> Non-default behaviour in HostMakeJobCallback</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-web-compat-host-ensure-can-add-private-field" title="Non-default behaviour in HostEnsureCanAddPrivateElement"><span class="secnum">B.3.8</span> Non-default behaviour in HostEnsureCanAddPrivateElement</a></li><li><span class="item-toggle-none"></span><a href="additional-ecmascript-features-for-web-browsers.html#sec-runtime-errors-for-function-call-assignment-targets" title="Runtime Errors for Function Call Assignment Targets"><span class="secnum">B.3.9</span> Runtime Errors for Function Call Assignment Targets</a></li></ol></li></ol></li><li><span class="item-toggle-none"></span><a href="strict-mode-of-ecmascript.html#sec-strict-mode-of-ecmascript" title="The Strict Mode of ECMAScript"><span class="secnum">Annex C <span class="annex-kind">(informative)</span></span> The Strict Mode of ECMAScript</a></li><li><span class="item-toggle">+</span><a href="host-layering-points.html#sec-host-layering-points" title="Host Layering Points"><span class="secnum">Annex D <span class="annex-kind">(informative)</span></span> Host Layering Points</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="host-layering-points.html#sec-host-hooks-summary" title="Host Hooks"><span class="secnum">D.1</span> Host Hooks</a></li><li><span class="item-toggle-none"></span><a href="host-layering-points.html#sec-host-defined-fields-summary" title="Host-defined Fields"><span class="secnum">D.2</span> Host-defined Fields</a></li><li><span class="item-toggle-none"></span><a href="host-layering-points.html#sec-host-defined-objects-summary" title="Host-defined Objects"><span class="secnum">D.3</span> Host-defined Objects</a></li><li><span class="item-toggle-none"></span><a href="host-layering-points.html#sec-host-running-jobs" title="Running Jobs"><span class="secnum">D.4</span> Running Jobs</a></li><li><span class="item-toggle-none"></span><a href="host-layering-points.html#sec-host-internal-methods-of-exotic-objects" title="Internal Methods of Exotic Objects"><span class="secnum">D.5</span> Internal Methods of Exotic Objects</a></li><li><span class="item-toggle-none"></span><a href="host-layering-points.html#sec-host-built-in-objects-and-methods" title="Built-in Objects and Methods"><span class="secnum">D.6</span> Built-in Objects and Methods</a></li></ol></li><li><span class="item-toggle-none"></span><a href="corrections-and-clarifications-in-ecmascript-2015-with-possible-compatibility-impact.html#sec-corrections-and-clarifications-in-ecmascript-2015-with-possible-compatibility-impact" title="Corrections and Clarifications in ECMAScript 2015 with Possible Compatibility Impact"><span class="secnum">Annex E <span class="annex-kind">(informative)</span></span> Corrections and Clarifications in ECMAScript 2015 with Possible Compatibility Impact</a></li><li><span class="item-toggle-none"></span><a href="additions-and-changes-that-introduce-incompatibilities-with-prior-editions.html#sec-additions-and-changes-that-introduce-incompatibilities-with-prior-editions" title="Additions and Changes That Introduce Incompatibilities with Prior Editions"><span class="secnum">Annex F <span class="annex-kind">(informative)</span></span> Additions and Changes That Introduce Incompatibilities with Prior Editions</a></li><li><span class="item-toggle-none"></span><a href="bibliography.html#sec-bibliography" title="Bibliography">Bibliography</a></li><li><span class="item-toggle-none"></span><a href="colophon.html#sec-colophon" title="Colophon">Colophon</a></li><li><span class="item-toggle-none"></span><a href="copyright-and-software-license.html#sec-copyright-and-software-license" title="Copyright &amp; Software License">Copyright &amp; Software License</a></li></ol></div></div>
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</ul></div><div id='spec-container'><emu-clause id="sec-control-abstraction-objects">
<h1><span class="secnum">27</span> Control Abstraction Objects</h1>
<emu-clause id="sec-iteration">
<h1><span class="secnum">27.1</span> Iteration</h1>
<emu-clause id="sec-common-iteration-interfaces">
<h1><span class="secnum">27.1.1</span> Common Iteration Interfaces</h1>
<p>An interface is a set of <emu-xref href="#property-key" id="_ref_15594"><a href="ecmascript-data-types-and-values.html#property-key">property keys</a></emu-xref> whose associated values match a specific specification. Any object that provides all the properties as described by an interface's specification <em>conforms</em> to that interface. An interface is not represented by a distinct object. There may be many separately implemented objects that conform to any interface. An individual object may conform to multiple interfaces.</p>
<emu-clause id="sec-iterable-interface">
<h1><span class="secnum">27.1.1.1</span> The Iterable Interface</h1>
<p>The <dfn variants="iterable,iterables,iterable object,iterable objects" tabindex="-1">iterable interface</dfn> includes the property described in <emu-xref href="#table-iterable-interface-required-properties" id="_ref_816"><a href="control-abstraction-objects.html#table-iterable-interface-required-properties">Table 77</a></emu-xref>:</p>
<emu-table id="table-iterable-interface-required-properties" caption="Iterable Interface Required Properties" oldids="table-52"><figure><figcaption>Table 77: <emu-xref href="#sec-iterable-interface" id="_ref_15595"><a href="control-abstraction-objects.html#sec-iterable-interface">Iterable</a></emu-xref> Interface Required Properties</figcaption><span id="table-52"></span>
<table>
<thead>
<tr>
<th>
Property
</th>
<th>
Value
</th>
<th>
Requirements
</th>
</tr>
</thead>
<tbody><tr>
<td>
<code>%Symbol.iterator%</code>
</td>
<td>
a function that returns an <emu-xref href="#sec-iterator-interface" id="_ref_15596"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref>
</td>
<td>
The returned object must conform to the <emu-xref href="#sec-iterator-interface" id="_ref_15597"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator interface</a></emu-xref>.
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-iterator-interface">
<h1><span class="secnum">27.1.1.2</span> The Iterator Interface</h1>
<p>An object that implements the <dfn variants="iterator object,iterator objects,iterator,iterators" tabindex="-1">iterator interface</dfn> must include the property in <emu-xref href="#table-iterator-interface-required-properties" id="_ref_817"><a href="control-abstraction-objects.html#table-iterator-interface-required-properties">Table 78</a></emu-xref>. Such objects may also implement the properties in <emu-xref href="#table-iterator-interface-optional-properties" id="_ref_818"><a href="control-abstraction-objects.html#table-iterator-interface-optional-properties">Table 79</a></emu-xref>.</p>
<emu-table id="table-iterator-interface-required-properties" caption="Iterator Interface Required Properties" oldids="table-53"><figure><figcaption>Table 78: <emu-xref href="#sec-iterator-interface" id="_ref_15598"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> Interface Required Properties</figcaption><span id="table-53"></span>
<table>
<thead>
<tr>
<th>
Property
</th>
<th>
Value
</th>
<th>
Requirements
</th>
</tr>
</thead>
<tbody><tr>
<td>
<emu-val>"next"</emu-val>
</td>
<td>
a function that returns an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15599"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref>
</td>
<td>
The returned object must conform to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15600"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>. If a previous call to the <code>next</code> method of an <emu-xref href="#sec-iterator-interface" id="_ref_15601"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> has returned an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15602"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> whose <emu-val>"done"</emu-val> property is <emu-val>true</emu-val>, then all subsequent calls to the <code>next</code> method of that object should also return an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15603"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> whose <emu-val>"done"</emu-val> property is <emu-val>true</emu-val>. However, this requirement is not enforced.
</td>
</tr>
</tbody></table>
</figure></emu-table>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>Arguments may be passed to the <code>next</code> function but their interpretation and validity is dependent upon the target iterator. The for-of statement and other common users of iterators do not pass any arguments, so iterator objects that expect to be used in such a manner must be prepared to deal with being called with no arguments.</p>
</div></emu-note>
<emu-table id="table-iterator-interface-optional-properties" caption="Iterator Interface Optional Properties" oldids="table-54"><figure><figcaption>Table 79: <emu-xref href="#sec-iterator-interface" id="_ref_15604"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> Interface Optional Properties</figcaption><span id="table-54"></span>
<table>
<thead>
<tr>
<th>
Property
</th>
<th>
Value
</th>
<th>
Requirements
</th>
</tr>
</thead>
<tbody><tr>
<td>
<emu-val>"return"</emu-val>
</td>
<td>
a function that returns an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15605"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref>
</td>
<td>
The returned object must conform to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15606"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>. Invoking this method notifies the <emu-xref href="#sec-iterator-interface" id="_ref_15607"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref> that the caller does not intend to make any more <code>next</code> method calls to the <emu-xref href="#sec-iterator-interface" id="_ref_15608"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>. The returned <emu-xref href="#sec-iteratorresult-interface" id="_ref_15609"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> will typically have a <emu-val>"done"</emu-val> property whose value is <emu-val>true</emu-val>, and a <emu-val>"value"</emu-val> property with the value passed as the argument of the <code>return</code> method. However, this requirement is not enforced.
</td>
</tr>
<tr>
<td>
<emu-val>"throw"</emu-val>
</td>
<td>
a function that returns an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15610"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref>
</td>
<td>
The returned object must conform to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15611"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>. Invoking this method notifies the <emu-xref href="#sec-iterator-interface" id="_ref_15612"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref> that the caller has detected an error condition. The argument may be used to identify the error condition and typically will be an exception object. A typical response is to <code>throw</code> the value passed as the argument. If the method does not <code>throw</code>, the returned <emu-xref href="#sec-iteratorresult-interface" id="_ref_15613"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> will typically have a <emu-val>"done"</emu-val> property whose value is <emu-val>true</emu-val>.
</td>
</tr>
</tbody></table>
</figure></emu-table>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>Typically callers of these methods should check for their existence before invoking them. Certain ECMAScript language features including <code>for</code>-<code>of</code>, <code>yield*</code>, and array destructuring call these methods after performing an existence check. Most ECMAScript library functions that accept <emu-xref href="#sec-iterable-interface" id="_ref_15614"><a href="control-abstraction-objects.html#sec-iterable-interface">iterable objects</a></emu-xref> as arguments also conditionally call them.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-asynciterable-interface">
<h1><span class="secnum">27.1.1.3</span> The Async Iterable Interface</h1>
<p>The <dfn variants="async iterable,async iterables,async iterable object,async iterable objects" tabindex="-1">async iterable interface</dfn> includes the properties described in <emu-xref href="#table-async-iterable" id="_ref_819"><a href="control-abstraction-objects.html#table-async-iterable">Table 80</a></emu-xref>:</p>
<emu-table id="table-async-iterable" caption="Async Iterable Interface Required Properties"><figure><figcaption>Table 80: Async <emu-xref href="#sec-iterable-interface" id="_ref_15615"><a href="control-abstraction-objects.html#sec-iterable-interface">Iterable</a></emu-xref> Interface Required Properties</figcaption>
<table>
<thead>
<tr>
<th>Property</th>
<th>Value</th>
<th>Requirements</th>
</tr>
</thead>
<tbody><tr>
<td><code>%Symbol.asyncIterator%</code></td>
<td>a function that returns an <emu-xref href="#sec-asynciterator-interface" id="_ref_15616"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator object</a></emu-xref></td>
<td>The returned object must conform to the <emu-xref href="#sec-asynciterator-interface" id="_ref_15617"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator interface</a></emu-xref>.</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-asynciterator-interface">
<h1><span class="secnum">27.1.1.4</span> The Async Iterator Interface</h1>
<p>An object that implements the <dfn variants="async iterator object,async iterator objects,async iterator,async iterators" tabindex="-1">async iterator interface</dfn> must include the properties in <emu-xref href="#table-async-iterator-required" id="_ref_820"><a href="control-abstraction-objects.html#table-async-iterator-required">Table 81</a></emu-xref>. Such objects may also implement the properties in <emu-xref href="#table-async-iterator-optional" id="_ref_821"><a href="control-abstraction-objects.html#table-async-iterator-optional">Table 82</a></emu-xref>.</p>
<emu-table id="table-async-iterator-required" caption="Async Iterator Interface Required Properties"><figure><figcaption>Table 81: Async <emu-xref href="#sec-iterator-interface" id="_ref_15618"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> Interface Required Properties</figcaption>
<table>
<thead>
<tr>
<th>Property</th>
<th>Value</th>
<th>Requirements</th>
</tr>
</thead>
<tbody><tr>
<td><emu-val>"next"</emu-val></td>
<td>a function that returns a promise for an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15619"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref></td>
<td>
<p>The returned promise, when fulfilled, must fulfill with an object that conforms to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15620"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>. If a previous call to the <code>next</code> method of an <emu-xref href="#sec-asynciterator-interface" id="_ref_15621"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator</a></emu-xref> has returned a promise for an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15622"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> whose <emu-val>"done"</emu-val> property is <emu-val>true</emu-val>, then all subsequent calls to the <code>next</code> method of that object should also return a promise for an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15623"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> whose <emu-val>"done"</emu-val> property is <emu-val>true</emu-val>. However, this requirement is not enforced.</p>
<p>Additionally, the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15624"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> that serves as a fulfillment value should have a <emu-val>"value"</emu-val> property whose value is not a promise (or "thenable"). However, this requirement is also not enforced.</p>
</td>
</tr>
</tbody></table>
</figure></emu-table>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>Arguments may be passed to the <code>next</code> function but their interpretation and validity is dependent upon the target async iterator. The <code>for</code>-<code>await</code>-<code>of</code> statement and other common users of async iterators do not pass any arguments, so async iterator objects that expect to be used in such a manner must be prepared to deal with being called with no arguments.</p>
</div></emu-note>
<emu-table id="table-async-iterator-optional" caption="Async Iterator Interface Optional Properties"><figure><figcaption>Table 82: Async <emu-xref href="#sec-iterator-interface" id="_ref_15625"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> Interface Optional Properties</figcaption>
<table>
<thead>
<tr>
<th>Property</th>
<th>Value</th>
<th>Requirements</th>
</tr>
</thead>
<tbody><tr>
<td><emu-val>"return"</emu-val></td>
<td>a function that returns a promise for an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15626"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref></td>
<td>
<p>The returned promise, when fulfilled, must fulfill with an object that conforms to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15627"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>. Invoking this method notifies the <emu-xref href="#sec-asynciterator-interface" id="_ref_15628"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator object</a></emu-xref> that the caller does not intend to make any more <code>next</code> method calls to the <emu-xref href="#sec-asynciterator-interface" id="_ref_15629"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator</a></emu-xref>. The returned promise will fulfill with an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15630"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> which will typically have a <emu-val>"done"</emu-val> property whose value is <emu-val>true</emu-val>, and a <emu-val>"value"</emu-val> property with the value passed as the argument of the <code>return</code> method. However, this requirement is not enforced.</p>
<p>Additionally, the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15631"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> that serves as a fulfillment value should have a <emu-val>"value"</emu-val> property whose value is not a promise (or "thenable"). If the argument value is used in the typical manner, then if it is a rejected promise, a promise rejected with the same reason should be returned; if it is a fulfilled promise, then its fulfillment value should be used as the <emu-val>"value"</emu-val> property of the returned promise's <emu-xref href="#sec-iteratorresult-interface" id="_ref_15632"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> fulfillment value. However, these requirements are also not enforced.</p>
</td>
</tr>
<tr>
<td><emu-val>"throw"</emu-val></td>
<td>a function that returns a promise for an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15633"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref></td>
<td>
<p>The returned promise, when fulfilled, must fulfill with an object that conforms to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15634"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>. Invoking this method notifies the <emu-xref href="#sec-asynciterator-interface" id="_ref_15635"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator object</a></emu-xref> that the caller has detected an error condition. The argument may be used to identify the error condition and typically will be an exception object. A typical response is to return a rejected promise which rejects with the value passed as the argument.</p>
<p>If the returned promise is fulfilled, the <emu-xref href="#sec-iteratorresult-interface" id="_ref_15636"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> fulfillment value will typically have a <emu-val>"done"</emu-val> property whose value is <emu-val>true</emu-val>. Additionally, it should have a <emu-val>"value"</emu-val> property whose value is not a promise (or "thenable"), but this requirement is not enforced.</p>
</td>
</tr>
</tbody></table>
</figure></emu-table>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>Typically callers of these methods should check for their existence before invoking them. Certain ECMAScript language features including <code>for</code>-<code>await</code>-<code>of</code> and <code>yield*</code> call these methods after performing an existence check.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-iteratorresult-interface">
<h1><span class="secnum">27.1.1.5</span> The IteratorResult Interface</h1>
<p>The <dfn variants="IteratorResult object,IteratorResult objects" tabindex="-1">IteratorResult interface</dfn> includes the properties listed in <emu-xref href="#table-iteratorresult-interface-properties" id="_ref_822"><a href="control-abstraction-objects.html#table-iteratorresult-interface-properties">Table 83</a></emu-xref>:</p>
<emu-table id="table-iteratorresult-interface-properties" caption="IteratorResult Interface Properties" oldids="table-55"><figure><figcaption>Table 83: IteratorResult Interface Properties</figcaption><span id="table-55"></span>
<table>
<thead>
<tr>
<th>
Property
</th>
<th>
Value
</th>
<th>
Requirements
</th>
</tr>
</thead>
<tbody><tr>
<td>
<emu-val>"done"</emu-val>
</td>
<td>
a Boolean
</td>
<td>
This is the result status of an <emu-xref href="#sec-iterator-interface" id="_ref_15637"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> <code>next</code> method call. If the end of the <emu-xref href="#sec-iterator-interface" id="_ref_15638"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> was reached <emu-val>"done"</emu-val> is <emu-val>true</emu-val>. If the end was not reached <emu-val>"done"</emu-val> is <emu-val>false</emu-val> and a value is available. If a <emu-val>"done"</emu-val> property (either own or inherited) does not exist, it is considered to have the value <emu-val>false</emu-val>.
</td>
</tr>
<tr>
<td>
<emu-val>"value"</emu-val>
</td>
<td>
an <emu-xref href="#sec-ecmascript-language-types" id="_ref_15639"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>
</td>
<td>
If done is <emu-val>false</emu-val>, this is the current iteration element value. If done is <emu-val>true</emu-val>, this is the return value of the <emu-xref href="#sec-iterator-interface" id="_ref_15640"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>, if it supplied one. If the <emu-xref href="#sec-iterator-interface" id="_ref_15641"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> does not have a return value, <emu-val>"value"</emu-val> is <emu-val>undefined</emu-val>. In that case, the <emu-val>"value"</emu-val> property may be absent from the conforming object if it does not inherit an explicit <emu-val>"value"</emu-val> property.
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
</emu-clause>
<emu-clause id="sec-iterator-helper-objects">
<h1><span class="secnum">27.1.2</span> Iterator Helper Objects</h1>
<p>An <dfn variants="Iterator Helper objects" tabindex="-1">Iterator Helper object</dfn> is an <emu-xref href="#ordinary-object" id="_ref_15642"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref> that represents a lazy transformation of some specific source <emu-xref href="#sec-iterator-interface" id="_ref_15643"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref>. There is not a named <emu-xref href="#constructor" id="_ref_15644"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> for Iterator Helper objects. Instead, Iterator Helper objects are created by calling certain methods of <emu-xref href="#sec-iterator-interface" id="_ref_15645"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> instance objects.</p>
<emu-clause id="sec-%iteratorhelperprototype%-object">
<h1><span class="secnum">27.1.2.1</span> The %IteratorHelperPrototype% Object</h1>
<p>The <dfn tabindex="-1">%IteratorHelperPrototype%</dfn> object:</p>
<ul>
<li>has properties that are inherited by all <emu-xref href="#sec-iterator-helper-objects" id="_ref_15646"><a href="control-abstraction-objects.html#sec-iterator-helper-objects">Iterator Helper objects</a></emu-xref>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_15647"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-%iterator.prototype%-object" id="_ref_15648"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">%Iterator.prototype%</a></emu-xref>.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-%iteratorhelperprototype%.next" type="built-in function">
<h1><span class="secnum">27.1.2.1.1</span> %IteratorHelperPrototype%.next ( )</h1>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="GeneratorResume" id="_ref_15649"><a href="control-abstraction-objects.html#sec-generatorresume" class="e-user-code">GeneratorResume</a></emu-xref>(<emu-val>this</emu-val> value, <emu-val>undefined</emu-val>, <emu-val>"Iterator Helper"</emu-val>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%iteratorhelperprototype%.return" type="built-in function">
<h1><span class="secnum">27.1.2.1.2</span> %IteratorHelperPrototype%.return ( )</h1>
<emu-alg><ol><li>Let <var>O</var> be <emu-val>this</emu-val> value.</li><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_15650"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>O</var>, <var class="field">[[UnderlyingIterators]]</var>).</li><li><emu-xref href="#assert" id="_ref_15651"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>O</var> has a <var class="field">[[GeneratorState]]</var> internal slot.</li><li>If <var>O</var>.<var class="field">[[GeneratorState]]</var> is <emu-const>suspended-start</emu-const>, then<ol><li>Set <var>O</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>completed</emu-const>.</li><li>NOTE: Once a generator enters the completed state it never leaves it and its associated <emu-xref href="#sec-execution-contexts" id="_ref_15652"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> is never resumed. Any execution state associated with <var>O</var> can be discarded at this point.</li><li>Perform ?&nbsp;<emu-xref aoid="IteratorCloseAll" id="_ref_15653"><a href="abstract-operations.html#sec-iteratorcloseall" class="e-user-code">IteratorCloseAll</a></emu-xref>(<var>O</var>.<var class="field">[[UnderlyingIterators]]</var>, <emu-xref aoid="NormalCompletion" id="_ref_15654"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-const>unused</emu-const>)).</li><li>Return <emu-xref aoid="CreateIteratorResultObject" id="_ref_15655"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<emu-val>undefined</emu-val>, <emu-val>true</emu-val>).</li></ol></li><li>Let <var>C</var> be <emu-xref aoid="ReturnCompletion" id="_ref_15656"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Return ?&nbsp;<emu-xref aoid="GeneratorResumeAbrupt" id="_ref_15657"><a href="control-abstraction-objects.html#sec-generatorresumeabrupt" class="e-user-code">GeneratorResumeAbrupt</a></emu-xref>(<var>O</var>, <var>C</var>, <emu-val>"Iterator Helper"</emu-val>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%iteratorhelperprototype%-%symbol.tostringtag%">
<h1><span class="secnum">27.1.2.1.3</span> %IteratorHelperPrototype% [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_15658"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"Iterator Helper"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-iterator-objects">
<h1><span class="secnum">27.1.3</span> Iterator Objects</h1>
<emu-clause id="sec-iterator-constructor">
<h1><span class="secnum">27.1.3.1</span> The Iterator Constructor</h1>
<p>The <dfn tabindex="-1">Iterator</dfn> <emu-xref href="#constructor" id="_ref_15659"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is <dfn tabindex="-1">%Iterator%</dfn>.</li>
<li>is the initial value of the <emu-val>"Iterator"</emu-val> property of the <emu-xref href="#sec-global-object" id="_ref_15660"><a href="global-object.html#sec-global-object">global object</a></emu-xref>.</li>
<li>is designed to be subclassable. It may be used as the value of an <emu-val>extends</emu-val> clause of a class definition.</li>
</ul>
<emu-clause id="sec-iterator" type="built-in function">
<h1><span class="secnum">27.1.3.1.1</span> Iterator ( )</h1>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>If NewTarget is either <emu-val>undefined</emu-val> or the <emu-xref href="#active-function-object" id="_ref_15661"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Return ?&nbsp;<emu-xref aoid="OrdinaryCreateFromConstructor" id="_ref_15662"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarycreatefromconstructor" class="e-user-code">OrdinaryCreateFromConstructor</a></emu-xref>(NewTarget, <emu-val>"%Iterator.prototype%"</emu-val>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-the-iterator-constructor">
<h1><span class="secnum">27.1.3.2</span> Properties of the Iterator Constructor</h1>
<p>The <emu-xref href="#sec-iterator-interface" id="_ref_15663"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> <emu-xref href="#constructor" id="_ref_15664"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-function-prototype-object" id="_ref_15665"><a href="fundamental-objects.html#sec-properties-of-the-function-prototype-object">%Function.prototype%</a></emu-xref>.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-iterator.concat" type="built-in function">
<h1><span class="secnum">27.1.3.2.1</span> Iterator.concat ( ...<var>items</var> )</h1>
<emu-alg><ol><li>Let <var>iterables</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_15666"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>For each element <var>item</var> of <var>items</var>, do<ol><li>If <var>item</var> <emu-xref href="#sec-object-type" id="_ref_15667"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>method</var> be ?&nbsp;<emu-xref aoid="GetMethod" id="_ref_15668"><a href="abstract-operations.html#sec-getmethod" class="e-user-code">GetMethod</a></emu-xref>(<var>item</var>, <emu-xref href="#sec-well-known-symbols" id="_ref_15669"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.iterator%</a></emu-xref>).</li><li>If <var>method</var> is <emu-val>undefined</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Append the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_15670"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[OpenMethod]]</var>: <var>method</var>, <var class="field">[[Iterable]]</var>: <var>item</var>&nbsp;} to <var>iterables</var>.</li></ol></li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15671"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>iterables</var> and performs the following steps when called:<ol><li>For each <emu-xref href="#sec-list-and-record-specification-type" id="_ref_15672"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> <var>iterable</var> of <var>iterables</var>, do<ol><li>Let <var>iter</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_15673"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>iterable</var>.<var class="field">[[OpenMethod]]</var>, <var>iterable</var>.<var class="field">[[Iterable]]</var>).</li><li>If <var>iter</var> <emu-xref href="#sec-object-type" id="_ref_15674"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iteratorRecord</var> be ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15675"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>iter</var>).</li><li>Let <var>innerAlive</var> be <emu-val>true</emu-val>.</li><li>Repeat, while <var>innerAlive</var> is <emu-val>true</emu-val>,<ol><li>Let <var>innerValue</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15676"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iteratorRecord</var>).</li><li>If <var>innerValue</var> is <emu-const>done</emu-const>, then<ol><li>Set <var>innerAlive</var> to <emu-val>false</emu-val>.</li></ol></li><li>Else,<ol><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_15677"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Yield" id="_ref_15678"><a href="control-abstraction-objects.html#sec-yield" class="e-user-code">Yield</a></emu-xref>(<var>innerValue</var>)).</li><li>If <var>completion</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_15679"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15680"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>completion</var>).</li></ol></li></ol></li></ol></li></ol></li><li>Return <emu-xref aoid="ReturnCompletion" id="_ref_15681"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Let <var>gen</var> be <emu-xref aoid="CreateIteratorFromClosure" id="_ref_15682"><a href="control-abstraction-objects.html#sec-createiteratorfromclosure">CreateIteratorFromClosure</a></emu-xref>(<var>closure</var>, <emu-val>"Iterator Helper"</emu-val>, <emu-xref href="#sec-%iteratorhelperprototype%-object" id="_ref_15683"><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object">%IteratorHelperPrototype%</a></emu-xref>, « <var class="field">[[UnderlyingIterators]]</var>&nbsp;»).</li><li>Set <var>gen</var>.<var class="field">[[UnderlyingIterators]]</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_15684"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Return <var>gen</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.from" type="built-in function">
<h1><span class="secnum">27.1.3.2.2</span> Iterator.from ( <var>O</var> )</h1>
<emu-alg><ol><li>Let <var>iteratorRecord</var> be ?&nbsp;<emu-xref aoid="GetIteratorFlattenable" id="_ref_15685"><a href="abstract-operations.html#sec-getiteratorflattenable" class="e-user-code">GetIteratorFlattenable</a></emu-xref>(<var>O</var>, <emu-const>iterate-string-primitives</emu-const>).</li><li>Let <var>hasInstance</var> be ?&nbsp;<emu-xref aoid="OrdinaryHasInstance" id="_ref_15686"><a href="abstract-operations.html#sec-ordinaryhasinstance" class="e-user-code">OrdinaryHasInstance</a></emu-xref>(<emu-xref href="#sec-iterator-constructor" id="_ref_15687"><a href="control-abstraction-objects.html#sec-iterator-constructor">%Iterator%</a></emu-xref>, <var>iteratorRecord</var>.<var class="field">[[Iterator]]</var>).</li><li>If <var>hasInstance</var> is <emu-val>true</emu-val>, then<ol><li>Return <var>iteratorRecord</var>.<var class="field">[[Iterator]]</var>.</li></ol></li><li>Let <var>wrapper</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_15688"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<emu-xref href="#sec-%wrapforvaliditeratorprototype%-object" id="_ref_15689"><a href="control-abstraction-objects.html#sec-%wrapforvaliditeratorprototype%-object">%WrapForValidIteratorPrototype%</a></emu-xref>, « <var class="field">[[Iterated]]</var>&nbsp;»).</li><li>Set <var>wrapper</var>.<var class="field">[[Iterated]]</var> to <var>iteratorRecord</var>.</li><li>Return <var>wrapper</var>.</li></ol></emu-alg>
<emu-clause id="sec-%wrapforvaliditeratorprototype%-object">
<h1><span class="secnum">27.1.3.2.2.1</span> The %WrapForValidIteratorPrototype% Object</h1>
<p>The <dfn tabindex="-1">%WrapForValidIteratorPrototype%</dfn> object:</p>
<ul>
<li>is an <emu-xref href="#ordinary-object" id="_ref_15690"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-%iterator.prototype%-object" id="_ref_15691"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">%Iterator.prototype%</a></emu-xref>.</li>
</ul>
<emu-clause id="sec-%wrapforvaliditeratorprototype%.next" type="built-in function">
<h1><span class="secnum">27.1.3.2.2.1.1</span> %WrapForValidIteratorPrototype%.next ( )</h1>
<emu-alg><ol><li>Let <var>O</var> be <emu-val>this</emu-val> value.</li><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_15692"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>O</var>, <var class="field">[[Iterated]]</var>).</li><li>Let <var>iteratorRecord</var> be <var>O</var>.<var class="field">[[Iterated]]</var>.</li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_15693"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>iteratorRecord</var>.<var class="field">[[NextMethod]]</var>, <var>iteratorRecord</var>.<var class="field">[[Iterator]]</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%wrapforvaliditeratorprototype%.return" type="built-in function">
<h1><span class="secnum">27.1.3.2.2.1.2</span> %WrapForValidIteratorPrototype%.return ( )</h1>
<emu-alg><ol><li>Let <var>O</var> be <emu-val>this</emu-val> value.</li><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_15694"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>O</var>, <var class="field">[[Iterated]]</var>).</li><li>Let <var>iterator</var> be <var>O</var>.<var class="field">[[Iterated]]</var>.<var class="field">[[Iterator]]</var>.</li><li><emu-xref href="#assert" id="_ref_15695"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>iterator</var> <emu-xref href="#sec-object-type" id="_ref_15696"><a href="ecmascript-data-types-and-values.html#sec-object-type">is an Object</a></emu-xref>.</li><li>Let <var>returnMethod</var> be ?&nbsp;<emu-xref aoid="GetMethod" id="_ref_15697"><a href="abstract-operations.html#sec-getmethod" class="e-user-code">GetMethod</a></emu-xref>(<var>iterator</var>, <emu-val>"return"</emu-val>).</li><li>If <var>returnMethod</var> is <emu-val>undefined</emu-val>, then<ol><li>Return <emu-xref aoid="CreateIteratorResultObject" id="_ref_15698"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<emu-val>undefined</emu-val>, <emu-val>true</emu-val>).</li></ol></li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_15699"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>returnMethod</var>, <var>iterator</var>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-iterator.prototype">
<h1><span class="secnum">27.1.3.2.3</span> Iterator.prototype</h1>
<p>The initial value of Iterator.prototype is the <emu-xref href="#sec-%iterator.prototype%-object" id="_ref_15700"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">Iterator prototype object</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause oldids="sec-%iteratorprototype%-object" id="sec-%iterator.prototype%-object"><span id="sec-%iteratorprototype%-object"></span>
<h1><span class="secnum">27.1.3.3</span> Properties of the Iterator Prototype Object</h1>
<p>The <dfn tabindex="-1">Iterator prototype object</dfn>:</p>
<ul>
<li>is <dfn tabindex="-1">%Iterator.prototype%</dfn>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-object-prototype-object" id="_ref_15701"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_15702"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>All objects defined in this specification that implement the <emu-xref href="#sec-iterator-interface" id="_ref_15703"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator interface</a></emu-xref> also inherit from %Iterator.prototype%. ECMAScript code may also define objects that inherit from %Iterator.prototype%. %Iterator.prototype% provides a place where additional methods that are applicable to all <emu-xref href="#sec-iterator-interface" id="_ref_15704"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator objects</a></emu-xref> may be added.</p>
<p>The following expression is one way that ECMAScript code can access the %Iterator.prototype% object:</p>
<pre><code class="javascript hljs"><span class="hljs-title class_">Object</span>.<span class="hljs-title function_">getPrototypeOf</span>(<span class="hljs-title class_">Object</span>.<span class="hljs-title function_">getPrototypeOf</span>([][<span class="hljs-title class_">Symbol</span>.<span class="hljs-property">iterator</span>]()))</code></pre>
</div></emu-note>
<emu-clause id="sec-iterator.prototype.constructor">
<h1><span class="secnum">27.1.3.3.1</span> Iterator.prototype.constructor</h1>
<p><code>Iterator.prototype.constructor</code> is an <emu-xref href="#sec-object-type" id="_ref_15705"><a href="ecmascript-data-types-and-values.html#sec-object-type">accessor property</a></emu-xref> with attributes { <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }. The <var class="field">[[Get]]</var> and <var class="field">[[Set]]</var> attributes are defined as follows:</p>
<emu-clause id="sec-get-iterator.prototype.constructor" type="built-in function">
<h1><span class="secnum">27.1.3.3.1.1</span> get Iterator.prototype.constructor</h1>
<p>The value of the <var class="field">[[Get]]</var> attribute is a built-in function that requires no arguments. It performs the following steps when called:</p>
<emu-alg><ol><li>Return <emu-xref href="#sec-iterator-constructor" id="_ref_15706"><a href="control-abstraction-objects.html#sec-iterator-constructor">%Iterator%</a></emu-xref>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-set-iterator.prototype.constructor" type="built-in function">
<h1><span class="secnum">27.1.3.3.1.2</span> set Iterator.prototype.constructor</h1>
<p>The value of the <var class="field">[[Set]]</var> attribute is a built-in function that takes an argument <var>v</var>. It performs the following steps when called:</p>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="SetterThatIgnoresPrototypeProperties" id="_ref_15707"><a href="abstract-operations.html#sec-SetterThatIgnoresPrototypeProperties" class="e-user-code">SetterThatIgnoresPrototypeProperties</a></emu-xref>(<emu-val>this</emu-val> value, <emu-xref href="#sec-%iterator.prototype%-object" id="_ref_15708"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">%Iterator.prototype%</a></emu-xref>, <emu-val>"constructor"</emu-val>, <var>v</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></emu-alg>
</emu-clause>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Unlike the <emu-val>"constructor"</emu-val> property on most built-in prototypes, for web-compatibility reasons this property must be an accessor.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-iterator.prototype.drop" type="built-in function">
<h1><span class="secnum">27.1.3.3.2</span> Iterator.prototype.drop ( <var>limit</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15709"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15710"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>Let <var>numLimit</var> be <emu-xref aoid="Completion" id="_ref_15711"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="ToNumber" id="_ref_15712"><a href="abstract-operations.html#sec-tonumber" class="e-user-code">ToNumber</a></emu-xref>(<var>limit</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15713"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>numLimit</var>, <var>iterated</var>).</li><li>If <var>numLimit</var> is <emu-val>NaN</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15714"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>RangeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15715"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Let <var>integerLimit</var> be !&nbsp;<emu-xref aoid="ToIntegerOrInfinity" id="_ref_15716"><a href="abstract-operations.html#sec-tointegerorinfinity">ToIntegerOrInfinity</a></emu-xref>(<var>numLimit</var>).</li><li>If <var>integerLimit</var> &lt; 0, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15717"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>RangeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15718"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15719"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15720"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>iterated</var> and <var>integerLimit</var> and performs the following steps when called:<ol><li>Let <var>remaining</var> be <var>integerLimit</var>.</li><li>Repeat, while <var>remaining</var> &gt; 0,<ol><li>If <var>remaining</var> ≠ +∞, then<ol><li>Set <var>remaining</var> to <var>remaining</var> - 1.</li></ol></li><li>Let <var>next</var> be ?&nbsp;<emu-xref aoid="IteratorStep" id="_ref_15721"><a href="abstract-operations.html#sec-iteratorstep" class="e-user-code">IteratorStep</a></emu-xref>(<var>iterated</var>).</li><li>If <var>next</var> is <emu-const>done</emu-const>, return <emu-xref aoid="ReturnCompletion" id="_ref_15722"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15723"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-xref aoid="ReturnCompletion" id="_ref_15724"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_15725"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Yield" id="_ref_15726"><a href="control-abstraction-objects.html#sec-yield" class="e-user-code">Yield</a></emu-xref>(<var>value</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15727"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>completion</var>, <var>iterated</var>).</li></ol></li></ol></li><li>Let <var>result</var> be <emu-xref aoid="CreateIteratorFromClosure" id="_ref_15728"><a href="control-abstraction-objects.html#sec-createiteratorfromclosure">CreateIteratorFromClosure</a></emu-xref>(<var>closure</var>, <emu-val>"Iterator Helper"</emu-val>, <emu-xref href="#sec-%iteratorhelperprototype%-object" id="_ref_15729"><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object">%IteratorHelperPrototype%</a></emu-xref>, « <var class="field">[[UnderlyingIterators]]</var>&nbsp;»).</li><li>Set <var>result</var>.<var class="field">[[UnderlyingIterators]]</var> to « <var>iterated</var>&nbsp;».</li><li>Return <var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.every" type="built-in function">
<h1><span class="secnum">27.1.3.3.3</span> Iterator.prototype.every ( <var>predicate</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15730"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15731"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15732"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>predicate</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15733"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15734"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15735"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15736"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-val>true</emu-val>.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15737"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15738"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>predicate</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15739"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15740"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>result</var>, <var>iterated</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_15741"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>result</var>) is <emu-val>false</emu-val>, return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15742"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <emu-xref aoid="NormalCompletion" id="_ref_15743"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>false</emu-val>)).</li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.filter" type="built-in function">
<h1><span class="secnum">27.1.3.3.4</span> Iterator.prototype.filter ( <var>predicate</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15744"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15745"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15746"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>predicate</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15747"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15748"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15749"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15750"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>iterated</var> and <var>predicate</var> and performs the following steps when called:<ol><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15751"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-xref aoid="ReturnCompletion" id="_ref_15752"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Let <var>selected</var> be <emu-xref aoid="Completion" id="_ref_15753"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15754"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>predicate</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15755"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15756"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>selected</var>, <var>iterated</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_15757"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>selected</var>) is <emu-val>true</emu-val>, then<ol><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_15758"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Yield" id="_ref_15759"><a href="control-abstraction-objects.html#sec-yield" class="e-user-code">Yield</a></emu-xref>(<var>value</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15760"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>completion</var>, <var>iterated</var>).</li></ol></li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></li><li>Let <var>result</var> be <emu-xref aoid="CreateIteratorFromClosure" id="_ref_15761"><a href="control-abstraction-objects.html#sec-createiteratorfromclosure">CreateIteratorFromClosure</a></emu-xref>(<var>closure</var>, <emu-val>"Iterator Helper"</emu-val>, <emu-xref href="#sec-%iteratorhelperprototype%-object" id="_ref_15762"><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object">%IteratorHelperPrototype%</a></emu-xref>, « <var class="field">[[UnderlyingIterators]]</var>&nbsp;»).</li><li>Set <var>result</var>.<var class="field">[[UnderlyingIterators]]</var> to « <var>iterated</var>&nbsp;».</li><li>Return <var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.find" type="built-in function">
<h1><span class="secnum">27.1.3.3.5</span> Iterator.prototype.find ( <var>predicate</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15763"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15764"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15765"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>predicate</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15766"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15767"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15768"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15769"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-val>undefined</emu-val>.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15770"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15771"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>predicate</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15772"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15773"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>result</var>, <var>iterated</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_15774"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>result</var>) is <emu-val>true</emu-val>, return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15775"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <emu-xref aoid="NormalCompletion" id="_ref_15776"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>value</var>)).</li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.flatmap" type="built-in function">
<h1><span class="secnum">27.1.3.3.6</span> Iterator.prototype.flatMap ( <var>mapper</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15777"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15778"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15779"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>mapper</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15780"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15781"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15782"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15783"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>iterated</var> and <var>mapper</var> and performs the following steps when called:<ol><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15784"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-xref aoid="ReturnCompletion" id="_ref_15785"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Let <var>mapped</var> be <emu-xref aoid="Completion" id="_ref_15786"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15787"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>mapper</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15788"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15789"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>mapped</var>, <var>iterated</var>).</li><li>Let <var>innerIterator</var> be <emu-xref aoid="Completion" id="_ref_15790"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetIteratorFlattenable" id="_ref_15791"><a href="abstract-operations.html#sec-getiteratorflattenable" class="e-user-code">GetIteratorFlattenable</a></emu-xref>(<var>mapped</var>, <emu-const>reject-primitives</emu-const>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15792"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>innerIterator</var>, <var>iterated</var>).</li><li>Let <var>innerAlive</var> be <emu-val>true</emu-val>.</li><li>Repeat, while <var>innerAlive</var> is <emu-val>true</emu-val>,<ol><li>Let <var>innerValue</var> be <emu-xref aoid="Completion" id="_ref_15793"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorStepValue" id="_ref_15794"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>innerIterator</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15795"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>innerValue</var>, <var>iterated</var>).</li><li>If <var>innerValue</var> is <emu-const>done</emu-const>, then<ol><li>Set <var>innerAlive</var> to <emu-val>false</emu-val>.</li></ol></li><li>Else,<ol><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_15796"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Yield" id="_ref_15797"><a href="control-abstraction-objects.html#sec-yield" class="e-user-code">Yield</a></emu-xref>(<var>innerValue</var>)).</li><li>If <var>completion</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_15798"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Let <var>backupCompletion</var> be <emu-xref aoid="Completion" id="_ref_15799"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_15800"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>innerIterator</var>, <var>completion</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15801"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>backupCompletion</var>, <var>iterated</var>).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15802"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>completion</var>).</li></ol></li></ol></li></ol></li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></li><li>Let <var>result</var> be <emu-xref aoid="CreateIteratorFromClosure" id="_ref_15803"><a href="control-abstraction-objects.html#sec-createiteratorfromclosure">CreateIteratorFromClosure</a></emu-xref>(<var>closure</var>, <emu-val>"Iterator Helper"</emu-val>, <emu-xref href="#sec-%iteratorhelperprototype%-object" id="_ref_15804"><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object">%IteratorHelperPrototype%</a></emu-xref>, « <var class="field">[[UnderlyingIterators]]</var>&nbsp;»).</li><li>Set <var>result</var>.<var class="field">[[UnderlyingIterators]]</var> to « <var>iterated</var>&nbsp;».</li><li>Return <var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.foreach" type="built-in function">
<h1><span class="secnum">27.1.3.3.7</span> Iterator.prototype.forEach ( <var>procedure</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15805"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15806"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15807"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>procedure</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15808"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15809"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15810"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15811"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-val>undefined</emu-val>.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15812"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15813"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>procedure</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15814"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15815"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>result</var>, <var>iterated</var>).</li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.map" type="built-in function">
<h1><span class="secnum">27.1.3.3.8</span> Iterator.prototype.map ( <var>mapper</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15816"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15817"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15818"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>mapper</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15819"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15820"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15821"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15822"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>iterated</var> and <var>mapper</var> and performs the following steps when called:<ol><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15823"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-xref aoid="ReturnCompletion" id="_ref_15824"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Let <var>mapped</var> be <emu-xref aoid="Completion" id="_ref_15825"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15826"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>mapper</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15827"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15828"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>mapped</var>, <var>iterated</var>).</li><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_15829"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Yield" id="_ref_15830"><a href="control-abstraction-objects.html#sec-yield" class="e-user-code">Yield</a></emu-xref>(<var>mapped</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15831"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>completion</var>, <var>iterated</var>).</li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></li><li>Let <var>result</var> be <emu-xref aoid="CreateIteratorFromClosure" id="_ref_15832"><a href="control-abstraction-objects.html#sec-createiteratorfromclosure">CreateIteratorFromClosure</a></emu-xref>(<var>closure</var>, <emu-val>"Iterator Helper"</emu-val>, <emu-xref href="#sec-%iteratorhelperprototype%-object" id="_ref_15833"><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object">%IteratorHelperPrototype%</a></emu-xref>, « <var class="field">[[UnderlyingIterators]]</var>&nbsp;»).</li><li>Set <var>result</var>.<var class="field">[[UnderlyingIterators]]</var> to « <var>iterated</var>&nbsp;».</li><li>Return <var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.reduce" type="built-in function">
<h1><span class="secnum">27.1.3.3.9</span> Iterator.prototype.reduce ( <var>reducer</var> [ , <var>initialValue</var> ] )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15834"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15835"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15836"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>reducer</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15837"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15838"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15839"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>If <var>initialValue</var> is not present, then<ol><li>Let <var>accumulator</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15840"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>accumulator</var> is <emu-const>done</emu-const>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>counter</var> be 1.</li></ol></li><li>Else,<ol><li>Let <var>accumulator</var> be <var>initialValue</var>.</li><li>Let <var>counter</var> be 0.</li></ol></li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15841"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <var>accumulator</var>.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15842"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15843"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>reducer</var>, <emu-val>undefined</emu-val>, « <var>accumulator</var>, <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15844"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15845"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>result</var>, <var>iterated</var>).</li><li>Set <var>accumulator</var> to <var>result</var>.</li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.some" type="built-in function">
<h1><span class="secnum">27.1.3.3.10</span> Iterator.prototype.some ( <var>predicate</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15846"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15847"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>If <emu-xref aoid="IsCallable" id="_ref_15848"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>predicate</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15849"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>TypeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15850"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15851"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>counter</var> be 0.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15852"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-val>false</emu-val>.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15853"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15854"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>predicate</var>, <emu-val>undefined</emu-val>, « <var>value</var>, <emu-xref aoid="𝔽" id="_ref_15855"><a href="notational-conventions.html#%F0%9D%94%BD">𝔽</a></emu-xref>(<var>counter</var>)&nbsp;»)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15856"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>result</var>, <var>iterated</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_15857"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>result</var>) is <emu-val>true</emu-val>, return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15858"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <emu-xref aoid="NormalCompletion" id="_ref_15859"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>true</emu-val>)).</li><li>Set <var>counter</var> to <var>counter</var> + 1.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.take" type="built-in function">
<h1><span class="secnum">27.1.3.3.11</span> Iterator.prototype.take ( <var>limit</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15860"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15861"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>O</var>, <var class="field">[[NextMethod]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>Let <var>numLimit</var> be <emu-xref aoid="Completion" id="_ref_15862"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="ToNumber" id="_ref_15863"><a href="abstract-operations.html#sec-tonumber" class="e-user-code">ToNumber</a></emu-xref>(<var>limit</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15864"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>numLimit</var>, <var>iterated</var>).</li><li>If <var>numLimit</var> is <emu-val>NaN</emu-val>, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15865"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>RangeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15866"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Let <var>integerLimit</var> be !&nbsp;<emu-xref aoid="ToIntegerOrInfinity" id="_ref_15867"><a href="abstract-operations.html#sec-tointegerorinfinity">ToIntegerOrInfinity</a></emu-xref>(<var>numLimit</var>).</li><li>If <var>integerLimit</var> &lt; 0, then<ol><li>Let <var>error</var> be <emu-xref aoid="ThrowCompletion" id="_ref_15868"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(a newly created <emu-val>RangeError</emu-val> object).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15869"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <var>error</var>).</li></ol></li><li>Set <var>iterated</var> to ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15870"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15871"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>iterated</var> and <var>integerLimit</var> and performs the following steps when called:<ol><li>Let <var>remaining</var> be <var>integerLimit</var>.</li><li>Repeat,<ol><li>If <var>remaining</var> = 0, then<ol><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15872"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iterated</var>, <emu-xref aoid="ReturnCompletion" id="_ref_15873"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>)).</li></ol></li><li>If <var>remaining</var> ≠ +∞, then<ol><li>Set <var>remaining</var> to <var>remaining</var> - 1.</li></ol></li><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15874"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-xref aoid="ReturnCompletion" id="_ref_15875"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_15876"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Yield" id="_ref_15877"><a href="control-abstraction-objects.html#sec-yield" class="e-user-code">Yield</a></emu-xref>(<var>value</var>)).</li><li><emu-xref aoid="IfAbruptCloseIterator" id="_ref_15878"><a href="abstract-operations.html#sec-ifabruptcloseiterator" class="e-user-code">IfAbruptCloseIterator</a></emu-xref>(<var>completion</var>, <var>iterated</var>).</li></ol></li></ol></li><li>Let <var>result</var> be <emu-xref aoid="CreateIteratorFromClosure" id="_ref_15879"><a href="control-abstraction-objects.html#sec-createiteratorfromclosure">CreateIteratorFromClosure</a></emu-xref>(<var>closure</var>, <emu-val>"Iterator Helper"</emu-val>, <emu-xref href="#sec-%iteratorhelperprototype%-object" id="_ref_15880"><a href="control-abstraction-objects.html#sec-%iteratorhelperprototype%-object">%IteratorHelperPrototype%</a></emu-xref>, « <var class="field">[[UnderlyingIterators]]</var>&nbsp;»).</li><li>Set <var>result</var>.<var class="field">[[UnderlyingIterators]]</var> to « <var>iterated</var>&nbsp;».</li><li>Return <var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-iterator.prototype.toarray" type="built-in function">
<h1><span class="secnum">27.1.3.3.12</span> Iterator.prototype.toArray ( )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li>If <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15881"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>iterated</var> be ?&nbsp;<emu-xref aoid="GetIteratorDirect" id="_ref_15882"><a href="abstract-operations.html#sec-getiteratordirect" class="e-user-code">GetIteratorDirect</a></emu-xref>(<var>O</var>).</li><li>Let <var>items</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_15883"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Repeat,<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_15884"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iterated</var>).</li><li>If <var>value</var> is <emu-const>done</emu-const>, return <emu-xref aoid="CreateArrayFromList" id="_ref_15885"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>items</var>).</li><li>Append <var>value</var> to <var>items</var>.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause oldids="sec-%iteratorprototype%-@@iterator,sec-%iteratorprototype%-%symbol.iterator%" id="sec-iterator.prototype-%symbol.iterator%" type="built-in function"><span id="sec-%iteratorprototype%-%symbol.iterator%"></span><span id="sec-%iteratorprototype%-@@iterator"></span>
<h1><span class="secnum">27.1.3.3.13</span> Iterator.prototype [ %Symbol.iterator% ] ( )</h1>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>Return the <emu-val>this</emu-val> value.</li></ol></emu-alg>
<p>The value of the <emu-val>"name"</emu-val> property of this function is <emu-val>"[Symbol.iterator]"</emu-val>.</p>
</emu-clause>
<emu-clause id="sec-iterator.prototype-%symbol.tostringtag%">
<h1><span class="secnum">27.1.3.3.14</span> Iterator.prototype [ %Symbol.toStringTag% ]</h1>
<p><code>Iterator.prototype[%Symbol.toStringTag%]</code> is an <emu-xref href="#sec-object-type" id="_ref_15886"><a href="ecmascript-data-types-and-values.html#sec-object-type">accessor property</a></emu-xref> with attributes { <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }. The <var class="field">[[Get]]</var> and <var class="field">[[Set]]</var> attributes are defined as follows:</p>
<emu-clause id="sec-get-iterator.prototype-%symbol.tostringtag%" type="built-in function">
<h1><span class="secnum">27.1.3.3.14.1</span> get Iterator.prototype [ %Symbol.toStringTag% ]</h1>
<p>The value of the <var class="field">[[Get]]</var> attribute is a built-in function that requires no arguments. It performs the following steps when called:</p>
<emu-alg><ol><li>Return <emu-val>"Iterator"</emu-val>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-set-iterator.prototype-%symbol.tostringtag%" type="built-in function">
<h1><span class="secnum">27.1.3.3.14.2</span> set Iterator.prototype [ %Symbol.toStringTag% ]</h1>
<p>The value of the <var class="field">[[Set]]</var> attribute is a built-in function that takes an argument <var>v</var>. It performs the following steps when called:</p>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="SetterThatIgnoresPrototypeProperties" id="_ref_15887"><a href="abstract-operations.html#sec-SetterThatIgnoresPrototypeProperties" class="e-user-code">SetterThatIgnoresPrototypeProperties</a></emu-xref>(<emu-val>this</emu-val> value, <emu-xref href="#sec-%iterator.prototype%-object" id="_ref_15888"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">%Iterator.prototype%</a></emu-xref>, <emu-xref href="#sec-well-known-symbols" id="_ref_15889"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref>, <var>v</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></emu-alg>
</emu-clause>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Unlike the <emu-xref href="#sec-well-known-symbols" id="_ref_15890"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property on most built-in prototypes, for web-compatibility reasons this property must be an accessor.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-asynciteratorprototype">
<h1><span class="secnum">27.1.4</span> The %AsyncIteratorPrototype% Object</h1>
<p>The <dfn tabindex="-1">%AsyncIteratorPrototype%</dfn> object:</p>
<ul>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-object-prototype-object" id="_ref_15891"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_15892"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>All objects defined in this specification that implement the <emu-xref href="#sec-asynciterator-interface" id="_ref_15893"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator interface</a></emu-xref> also inherit from %AsyncIteratorPrototype%. ECMAScript code may also define objects that inherit from %AsyncIteratorPrototype%. The %AsyncIteratorPrototype% object provides a place where additional methods that are applicable to all <emu-xref href="#sec-asynciterator-interface" id="_ref_15894"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator objects</a></emu-xref> may be added.</p>
</div></emu-note>
<emu-clause oldids="sec-asynciteratorprototype-asynciterator" id="sec-%asynciteratorprototype%-%symbol.asynciterator%" type="built-in function"><span id="sec-asynciteratorprototype-asynciterator"></span>
<h1><span class="secnum">27.1.4.1</span> %AsyncIteratorPrototype% [ %Symbol.asyncIterator% ] ( )</h1>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>Return the <emu-val>this</emu-val> value.</li></ol></emu-alg>
<p>The value of the <emu-val>"name"</emu-val> property of this function is <emu-val>"[Symbol.asyncIterator]"</emu-val>.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-async-from-sync-iterator-objects">
<h1><span class="secnum">27.1.5</span> Async-from-Sync Iterator Objects</h1>
<p>An <dfn variants="Async-from-Sync Iterator objects" tabindex="-1">Async-from-Sync Iterator object</dfn> is an <emu-xref href="#sec-asynciterator-interface" id="_ref_15895"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator</a></emu-xref> that adapts a specific synchronous <emu-xref href="#sec-iterator-interface" id="_ref_15896"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>. Async-from-Sync Iterator objects are never directly accessible to ECMAScript code. There is not a named <emu-xref href="#constructor" id="_ref_15897"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> for Async-from-Sync Iterator objects. Instead, Async-from-Sync Iterator objects are created by the <emu-xref aoid="CreateAsyncFromSyncIterator" id="_ref_15898"><a href="control-abstraction-objects.html#sec-createasyncfromsynciterator">CreateAsyncFromSyncIterator</a></emu-xref> abstract operation as needed.</p>
<emu-clause id="sec-createasyncfromsynciterator" type="abstract operation" aoid="CreateAsyncFromSyncIterator">
<h1><span class="secnum">27.1.5.1</span> CreateAsyncFromSyncIterator ( <var>syncIteratorRecord</var> )</h1>
<p>The abstract operation CreateAsyncFromSyncIterator takes argument <var>syncIteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_15899"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>) and returns an <emu-xref href="#sec-iterator-records" id="_ref_15900"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>. It is used to create an async <emu-xref href="#sec-iterator-records" id="_ref_15901"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> from a synchronous <emu-xref href="#sec-iterator-records" id="_ref_15902"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>asyncIterator</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_15903"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<emu-xref href="#sec-%asyncfromsynciteratorprototype%-object" id="_ref_15904"><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%-object">%AsyncFromSyncIteratorPrototype%</a></emu-xref>, « <var class="field">[[SyncIteratorRecord]]</var>&nbsp;»).</li><li>Set <var>asyncIterator</var>.<var class="field">[[SyncIteratorRecord]]</var> to <var>syncIteratorRecord</var>.</li><li>Let <var>nextMethod</var> be !&nbsp;<emu-xref aoid="Get" id="_ref_15905"><a href="abstract-operations.html#sec-get-o-p">Get</a></emu-xref>(<var>asyncIterator</var>, <emu-val>"next"</emu-val>).</li><li>Let <var>iteratorRecord</var> be the <emu-xref href="#sec-iterator-records" id="_ref_15906"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>asyncIterator</var>, <var class="field">[[NextMethod]]</var>: <var>nextMethod</var>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>Return <var>iteratorRecord</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%asyncfromsynciteratorprototype%-object">
<h1><span class="secnum">27.1.5.2</span> The %AsyncFromSyncIteratorPrototype% Object</h1>
<p>The <dfn tabindex="-1">%AsyncFromSyncIteratorPrototype%</dfn> object:</p>
<ul>
<li>has properties that are inherited by all <emu-xref href="#sec-async-from-sync-iterator-objects" id="_ref_15907"><a href="control-abstraction-objects.html#sec-async-from-sync-iterator-objects">Async-from-Sync Iterator objects</a></emu-xref>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_15908"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-asynciteratorprototype" id="_ref_15909"><a href="control-abstraction-objects.html#sec-asynciteratorprototype">%AsyncIteratorPrototype%</a></emu-xref>.</li>
<li>is never directly accessible to ECMAScript code.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-%asyncfromsynciteratorprototype%.next" type="built-in function">
<h1><span class="secnum">27.1.5.2.1</span> %AsyncFromSyncIteratorPrototype%.next ( [ <var>value</var> ] )</h1>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li><emu-xref href="#assert" id="_ref_15910"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15911"><a href="ecmascript-data-types-and-values.html#sec-object-type">is an Object</a></emu-xref> that has a <var class="field">[[SyncIteratorRecord]]</var> internal slot.</li><li>Let <var>promiseCapability</var> be !&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_15912"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_15913"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>syncIteratorRecord</var> be <var>O</var>.<var class="field">[[SyncIteratorRecord]]</var>.</li><li>If <var>value</var> is present, then<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15914"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorNext" id="_ref_15915"><a href="abstract-operations.html#sec-iteratornext" class="e-user-code">IteratorNext</a></emu-xref>(<var>syncIteratorRecord</var>, <var>value</var>)).</li></ol></li><li>Else,<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15916"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorNext" id="_ref_15917"><a href="abstract-operations.html#sec-iteratornext" class="e-user-code">IteratorNext</a></emu-xref>(<var>syncIteratorRecord</var>)).</li></ol></li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15918"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>Return <emu-xref aoid="AsyncFromSyncIteratorContinuation" id="_ref_15919"><a href="control-abstraction-objects.html#sec-asyncfromsynciteratorcontinuation" class="e-user-code">AsyncFromSyncIteratorContinuation</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>, <var>syncIteratorRecord</var>, <emu-val>true</emu-val>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%asyncfromsynciteratorprototype%.return" type="built-in function">
<h1><span class="secnum">27.1.5.2.2</span> %AsyncFromSyncIteratorPrototype%.return ( [ <var>value</var> ] )</h1>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li><emu-xref href="#assert" id="_ref_15920"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15921"><a href="ecmascript-data-types-and-values.html#sec-object-type">is an Object</a></emu-xref> that has a <var class="field">[[SyncIteratorRecord]]</var> internal slot.</li><li>Let <var>promiseCapability</var> be !&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_15922"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_15923"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>syncIteratorRecord</var> be <var>O</var>.<var class="field">[[SyncIteratorRecord]]</var>.</li><li>Let <var>syncIterator</var> be <var>syncIteratorRecord</var>.<var class="field">[[Iterator]]</var>.</li><li>Let <var>return</var> be <emu-xref aoid="Completion" id="_ref_15924"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetMethod" id="_ref_15925"><a href="abstract-operations.html#sec-getmethod" class="e-user-code">GetMethod</a></emu-xref>(<var>syncIterator</var>, <emu-val>"return"</emu-val>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15926"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>return</var>, <var>promiseCapability</var>).</li><li>If <var>return</var> is <emu-val>undefined</emu-val>, then<ol><li>Let <var>iteratorResult</var> be <emu-xref aoid="CreateIteratorResultObject" id="_ref_15927"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>value</var>, <emu-val>true</emu-val>).</li><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_15928"><a href="abstract-operations.html#sec-call" class="e-user-code e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>iteratorResult</var>&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>If <var>value</var> is present, then<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15929"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15930"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>return</var>, <var>syncIterator</var>, « <var>value</var>&nbsp;»)).</li></ol></li><li>Else,<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15931"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15932"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>return</var>, <var>syncIterator</var>)).</li></ol></li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15933"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>If <var>result</var> <emu-xref href="#sec-object-type" id="_ref_15934"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, then<ol><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_15935"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « a newly created <emu-val>TypeError</emu-val> object&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Return <emu-xref aoid="AsyncFromSyncIteratorContinuation" id="_ref_15936"><a href="control-abstraction-objects.html#sec-asyncfromsynciteratorcontinuation" class="e-user-code">AsyncFromSyncIteratorContinuation</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>, <var>syncIteratorRecord</var>, <emu-val>false</emu-val>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%asyncfromsynciteratorprototype%.throw" type="built-in function">
<h1><span class="secnum">27.1.5.2.3</span> %AsyncFromSyncIteratorPrototype%.throw ( [ <var>value</var> ] )</h1>
<emu-note><span class="note">Note</span><div class="note-contents">In this specification, <var>value</var> is always provided, but is left optional for consistency with <emu-xref title="" href="#sec-%asyncfromsynciteratorprototype%.return" id="_ref_823"><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%.return">%AsyncFromSyncIteratorPrototype%.return ( [ <var>value</var> ] )</a></emu-xref>.</div></emu-note>
<emu-alg><ol><li>Let <var>O</var> be the <emu-val>this</emu-val> value.</li><li><emu-xref href="#assert" id="_ref_15937"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>O</var> <emu-xref href="#sec-object-type" id="_ref_15938"><a href="ecmascript-data-types-and-values.html#sec-object-type">is an Object</a></emu-xref> that has a <var class="field">[[SyncIteratorRecord]]</var> internal slot.</li><li>Let <var>promiseCapability</var> be !&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_15939"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_15940"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>syncIteratorRecord</var> be <var>O</var>.<var class="field">[[SyncIteratorRecord]]</var>.</li><li>Let <var>syncIterator</var> be <var>syncIteratorRecord</var>.<var class="field">[[Iterator]]</var>.</li><li>Let <var>throw</var> be <emu-xref aoid="Completion" id="_ref_15941"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetMethod" id="_ref_15942"><a href="abstract-operations.html#sec-getmethod" class="e-user-code">GetMethod</a></emu-xref>(<var>syncIterator</var>, <emu-val>"throw"</emu-val>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15943"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>throw</var>, <var>promiseCapability</var>).</li><li>If <var>throw</var> is <emu-val>undefined</emu-val>, then<ol><li>NOTE: If <var>syncIterator</var> does not have a <code>throw</code> method, close it to give it a chance to clean up before we reject the capability.</li><li>Let <var>closeCompletion</var> be <emu-xref aoid="NormalCompletion" id="_ref_15944"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-const>empty</emu-const>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15945"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_15946"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>syncIteratorRecord</var>, <var>closeCompletion</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15947"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>NOTE: The next step throws a <emu-val>TypeError</emu-val> to indicate that there was a protocol violation: <var>syncIterator</var> does not have a <code>throw</code> method.</li><li>NOTE: If closing <var>syncIterator</var> does not throw then the result of that operation is ignored, even if it yields a rejected promise.</li><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_15948"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « a newly created <emu-val>TypeError</emu-val> object&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>If <var>value</var> is present, then<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15949"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15950"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>throw</var>, <var>syncIterator</var>, « <var>value</var>&nbsp;»)).</li></ol></li><li>Else,<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_15951"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_15952"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>throw</var>, <var>syncIterator</var>)).</li></ol></li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15953"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>If <var>result</var> <emu-xref href="#sec-object-type" id="_ref_15954"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, then<ol><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_15955"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « a newly created <emu-val>TypeError</emu-val> object&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Return <emu-xref aoid="AsyncFromSyncIteratorContinuation" id="_ref_15956"><a href="control-abstraction-objects.html#sec-asyncfromsynciteratorcontinuation" class="e-user-code">AsyncFromSyncIteratorContinuation</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>, <var>syncIteratorRecord</var>, <emu-val>true</emu-val>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-async-from-sync-iterator-instances">
<h1><span class="secnum">27.1.5.3</span> Properties of Async-from-Sync Iterator Instances</h1>
<p>Async-from-Sync <emu-xref href="#sec-iterator-interface" id="_ref_15957"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> instances are <emu-xref href="#ordinary-object" id="_ref_15958"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary objects</a></emu-xref> that inherit properties from the <emu-xref href="#sec-%asyncfromsynciteratorprototype%-object" id="_ref_15959"><a href="control-abstraction-objects.html#sec-%asyncfromsynciteratorprototype%-object">%AsyncFromSyncIteratorPrototype%</a></emu-xref> intrinsic object. Async-from-Sync <emu-xref href="#sec-iterator-interface" id="_ref_15960"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> instances are initially created with the internal slots listed in <emu-xref href="#table-async-from-sync-iterator-internal-slots" id="_ref_824"><a href="control-abstraction-objects.html#table-async-from-sync-iterator-internal-slots">Table 84</a></emu-xref>.</p>
<emu-table id="table-async-from-sync-iterator-internal-slots" caption="Internal Slots of Async-from-Sync Iterator Instances"><figure><figcaption>Table 84: Internal Slots of Async-from-Sync <emu-xref href="#sec-iterator-interface" id="_ref_15961"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> Instances</figcaption>
<table>
<thead>
<tr>
<th>
Internal Slot
</th>
<th>
Type
</th>
<th>
Description
</th>
</tr>
</thead>
<tbody><tr>
<td>
<var class="field">[[SyncIteratorRecord]]</var>
</td>
<td>
an <emu-xref href="#sec-iterator-records" id="_ref_15962"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>
</td>
<td>
Represents the original synchronous <emu-xref href="#sec-iterator-interface" id="_ref_15963"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> which is being adapted.
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-asyncfromsynciteratorcontinuation" type="abstract operation" oldids="sec-async-from-sync-iterator-value-unwrap-functions" aoid="AsyncFromSyncIteratorContinuation"><span id="sec-async-from-sync-iterator-value-unwrap-functions"></span>
<h1><span class="secnum">27.1.5.4</span> AsyncFromSyncIteratorContinuation ( <var>result</var>, <var>promiseCapability</var>, <var>syncIteratorRecord</var>, <var>closeOnRejection</var> )</h1>
<p>The abstract operation AsyncFromSyncIteratorContinuation takes arguments <var>result</var> (an Object), <var>promiseCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_15964"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref> for an intrinsic <emu-xref href="#sec-promise-constructor" id="_ref_15965"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>), <var>syncIteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_15966"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>), and <var>closeOnRejection</var> (a Boolean) and returns a Promise. It performs the following steps when called:</p>
<emu-alg><ol><li>NOTE: Because <var>promiseCapability</var> is derived from the intrinsic <emu-xref href="#sec-promise-constructor" id="_ref_15967"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>, the calls to <var>promiseCapability</var>.<var class="field">[[Reject]]</var> entailed by the use <emu-xref aoid="IfAbruptRejectPromise" id="_ref_15968"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise">IfAbruptRejectPromise</a></emu-xref> below are guaranteed not to throw.</li><li>Let <var>done</var> be <emu-xref aoid="Completion" id="_ref_15969"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorComplete" id="_ref_15970"><a href="abstract-operations.html#sec-iteratorcomplete" class="e-user-code">IteratorComplete</a></emu-xref>(<var>result</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15971"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>done</var>, <var>promiseCapability</var>).</li><li>Let <var>value</var> be <emu-xref aoid="Completion" id="_ref_15972"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorValue" id="_ref_15973"><a href="abstract-operations.html#sec-iteratorvalue" class="e-user-code">IteratorValue</a></emu-xref>(<var>result</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15974"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>value</var>, <var>promiseCapability</var>).</li><li>Let <var>valueWrapper</var> be <emu-xref aoid="Completion" id="_ref_15975"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PromiseResolve" id="_ref_15976"><a href="control-abstraction-objects.html#sec-promise-resolve" class="e-user-code">PromiseResolve</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_15977"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>, <var>value</var>)).</li><li>If <var>valueWrapper</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_15978"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, <var>done</var> is <emu-val>false</emu-val>, and <var>closeOnRejection</var> is <emu-val>true</emu-val>, then<ol><li>Set <var>valueWrapper</var> to <emu-xref aoid="Completion" id="_ref_15979"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_15980"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>syncIteratorRecord</var>, <var>valueWrapper</var>)).</li></ol></li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_15981"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>valueWrapper</var>, <var>promiseCapability</var>).</li><li>Let <var>unwrap</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15982"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>v</var>) that captures <var>done</var> and performs the following steps when called:<ol><li>Return <emu-xref aoid="CreateIteratorResultObject" id="_ref_15983"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>v</var>, <var>done</var>).</li></ol></li><li>Let <var>onFulfilled</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_15984"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>unwrap</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>NOTE: <var>onFulfilled</var> is used when processing the <emu-val>"value"</emu-val> property of an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15985"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> in order to wait for its value if it is a promise and re-package the result in a new "unwrapped" <emu-xref href="#sec-iteratorresult-interface" id="_ref_15986"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref>.</li><li>If <var>done</var> is <emu-val>true</emu-val>, or if <var>closeOnRejection</var> is <emu-val>false</emu-val>, then<ol><li>Let <var>onRejected</var> be <emu-val>undefined</emu-val>.</li></ol></li><li>Else,<ol><li>Let <var>closeIterator</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_15987"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>error</var>) that captures <var>syncIteratorRecord</var> and performs the following steps when called:<ol><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_15988"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>syncIteratorRecord</var>, <emu-xref aoid="ThrowCompletion" id="_ref_15989"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>error</var>)).</li></ol></li><li>Let <var>onRejected</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_15990"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>closeIterator</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>NOTE: <var>onRejected</var> is used to close the <emu-xref href="#sec-iterator-interface" id="_ref_15991"><a href="control-abstraction-objects.html#sec-iterator-interface">Iterator</a></emu-xref> when the <emu-val>"value"</emu-val> property of an <emu-xref href="#sec-iteratorresult-interface" id="_ref_15992"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref> it yields is a rejected promise.</li></ol></li><li>Perform <emu-xref aoid="PerformPromiseThen" id="_ref_15993"><a href="control-abstraction-objects.html#sec-performpromisethen">PerformPromiseThen</a></emu-xref>(<var>valueWrapper</var>, <var>onFulfilled</var>, <var>onRejected</var>, <var>promiseCapability</var>).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise-objects">
<h1><span class="secnum">27.2</span> Promise Objects</h1>
<p>A Promise is an object that is used as a placeholder for the eventual results of a deferred (and possibly asynchronous) computation.</p>
<p>Any Promise is in one of three mutually exclusive states: <em>fulfilled</em>, <em>rejected</em>, and <em>pending</em>:</p>
<ul>
<li>
A promise <code>p</code> is fulfilled if <code>p.then(f, r)</code> will immediately enqueue a <emu-xref href="#job" id="_ref_15994"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> to call the function <code>f</code>.
</li>
<li>
A promise <code>p</code> is rejected if <code>p.then(f, r)</code> will immediately enqueue a <emu-xref href="#job" id="_ref_15995"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> to call the function <code>r</code>.
</li>
<li>
A promise is pending if it is neither fulfilled nor rejected.
</li>
</ul>
<p>A promise is said to be <em>settled</em> if it is not pending, i.e. if it is either fulfilled or rejected.</p>
<p>A promise is <em>resolved</em> if it is settled or if it has been “locked in” to match the state of another promise. Attempting to resolve or reject a resolved promise has no effect. A promise is <em>unresolved</em> if it is not resolved. An unresolved promise is always in the pending state. A resolved promise may be pending, fulfilled or rejected.</p>
<emu-clause id="sec-promise-abstract-operations">
<h1><span class="secnum">27.2.1</span> Promise Abstract Operations</h1>
<emu-clause id="sec-promisecapability-records">
<h1><span class="secnum">27.2.1.1</span> PromiseCapability Records</h1>
<p>A <dfn variants="PromiseCapability Records" tabindex="-1">PromiseCapability Record</dfn> is a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_15996"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> value used to encapsulate a Promise or promise-like object along with the functions that are capable of resolving or rejecting that promise. PromiseCapability Records are produced by the <emu-xref aoid="NewPromiseCapability" id="_ref_15997"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref> abstract operation.</p>
<p>PromiseCapability Records have the fields listed in <emu-xref href="#table-promisecapability-record-fields" id="_ref_825"><a href="control-abstraction-objects.html#table-promisecapability-record-fields">Table 85</a></emu-xref>.</p>
<emu-table id="table-promisecapability-record-fields" caption="PromiseCapability Record Fields" oldids="table-57"><figure><figcaption>Table 85: <emu-xref href="#sec-promisecapability-records" id="_ref_15998"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref> Fields</figcaption><span id="table-57"></span>
<table>
<thead>
<tr>
<th>
Field Name
</th>
<th>
Value
</th>
<th>
Meaning
</th>
</tr>
</thead>
<tbody><tr>
<td>
<var class="field">[[Promise]]</var>
</td>
<td>
an Object
</td>
<td>
An object that is usable as a promise.
</td>
</tr>
<tr>
<td>
<var class="field">[[Resolve]]</var>
</td>
<td>
a <emu-xref href="#function-object" id="_ref_15999"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>
</td>
<td>
The function that is used to resolve the given promise.
</td>
</tr>
<tr>
<td>
<var class="field">[[Reject]]</var>
</td>
<td>
a <emu-xref href="#function-object" id="_ref_16000"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>
</td>
<td>
The function that is used to reject the given promise.
</td>
</tr>
</tbody></table>
</figure></emu-table>
<emu-clause id="sec-ifabruptrejectpromise" aoid="IfAbruptRejectPromise">
<h1><span class="secnum">27.2.1.1.1</span> IfAbruptRejectPromise ( <var>value</var>, <var>capability</var> )</h1>
<p>IfAbruptRejectPromise is a shorthand for a sequence of algorithm steps that use a <emu-xref href="#sec-promisecapability-records" id="_ref_16001"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>. An algorithm step of the form:</p>
<emu-alg><ol><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16002"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>value</var>, <var>capability</var>).</li></ol></emu-alg>
<p>means the same thing as:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16003"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>value</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16004"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>.</li><li>If <var>value</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16005"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16006"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>capability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>value</var>.<var class="field">[[Value]]</var>&nbsp;»).</li><li>Return <var>capability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Set <var>value</var> to !&nbsp;<var>value</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promisereaction-records">
<h1><span class="secnum">27.2.1.2</span> PromiseReaction Records</h1>
<p>A <dfn variants="PromiseReaction Records" tabindex="-1">PromiseReaction Record</dfn> is a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16007"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> value used to store information about how a promise should react when it becomes resolved or rejected with a given value. PromiseReaction Records are created by the <emu-xref aoid="PerformPromiseThen" id="_ref_16008"><a href="control-abstraction-objects.html#sec-performpromisethen">PerformPromiseThen</a></emu-xref> abstract operation, and are used by the <emu-xref href="#sec-abstract-closure" id="_ref_16009"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> returned by <emu-xref aoid="NewPromiseReactionJob" id="_ref_16010"><a href="control-abstraction-objects.html#sec-newpromisereactionjob">NewPromiseReactionJob</a></emu-xref>.</p>
<p>PromiseReaction Records have the fields listed in <emu-xref href="#table-promisereaction-record-fields" id="_ref_826"><a href="control-abstraction-objects.html#table-promisereaction-record-fields">Table 86</a></emu-xref>.</p>
<emu-table id="table-promisereaction-record-fields" caption="PromiseReaction Record Fields" oldids="table-58"><figure><figcaption>Table 86: <emu-xref href="#sec-promisereaction-records" id="_ref_16011"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Record</a></emu-xref> Fields</figcaption><span id="table-58"></span>
<table>
<thead>
<tr>
<th>
Field Name
</th>
<th>
Value
</th>
<th>
Meaning
</th>
</tr>
</thead>
<tbody><tr>
<td>
<var class="field">[[Capability]]</var>
</td>
<td>
a <emu-xref href="#sec-promisecapability-records" id="_ref_16012"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref> or <emu-val>undefined</emu-val>
</td>
<td>
The capabilities of the promise for which this record provides a reaction handler.
</td>
</tr>
<tr>
<td>
<var class="field">[[Type]]</var>
</td>
<td>
<emu-const>fulfill</emu-const> or <emu-const>reject</emu-const>
</td>
<td>
The <var class="field">[[Type]]</var> is used when <var class="field">[[Handler]]</var> is <emu-const>empty</emu-const> to allow for behaviour specific to the settlement type.
</td>
</tr>
<tr>
<td>
<var class="field">[[Handler]]</var>
</td>
<td>
a <emu-xref href="#sec-jobcallback-records" id="_ref_16013"><a href="executable-code-and-execution-contexts.html#sec-jobcallback-records">JobCallback Record</a></emu-xref> or <emu-const>empty</emu-const>
</td>
<td>
The function that should be applied to the incoming value, and whose return value will govern what happens to the derived promise. If <var class="field">[[Handler]]</var> is <emu-const>empty</emu-const>, a function that depends on the value of <var class="field">[[Type]]</var> will be used instead.
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-createresolvingfunctions" oldids="sec-promise-reject-functions,sec-promise-resolve-functions" type="abstract operation" aoid="CreateResolvingFunctions"><span id="sec-promise-resolve-functions"></span><span id="sec-promise-reject-functions"></span>
<h1><span class="secnum">27.2.1.3</span> CreateResolvingFunctions ( <var>toResolve</var> )</h1>
<p>The abstract operation CreateResolvingFunctions takes argument <var>toResolve</var> (a Promise) and returns a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16014"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> with fields <var class="field">[[Resolve]]</var> (a <emu-xref href="#function-object" id="_ref_16015"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>) and <var class="field">[[Reject]]</var> (a <emu-xref href="#function-object" id="_ref_16016"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>). It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>promiseOrEmpty</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16017"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Value]]</var>: <var>toResolve</var>&nbsp;}.</li><li>Let <var>resolveSteps</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16018"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>resolution</var>) that captures <var>promiseOrEmpty</var> and performs the following steps when called:<ol><li>If <var>promiseOrEmpty</var>.<var class="field">[[Value]]</var> is <emu-const>empty</emu-const>, return <emu-val>undefined</emu-val>.</li><li>Let <var>promise</var> be <var>promiseOrEmpty</var>.<var class="field">[[Value]]</var>.</li><li>Set <var>promiseOrEmpty</var>.<var class="field">[[Value]]</var> to <emu-const>empty</emu-const>.</li><li>If <emu-xref aoid="SameValue" id="_ref_16019"><a href="abstract-operations.html#sec-samevalue">SameValue</a></emu-xref>(<var>resolution</var>, <var>promise</var>) is <emu-val>true</emu-val>, then<ol><li>Let <var>selfResolutionError</var> be a newly created <emu-val>TypeError</emu-val> object.</li><li>Perform <emu-xref aoid="RejectPromise" id="_ref_16020"><a href="control-abstraction-objects.html#sec-rejectpromise">RejectPromise</a></emu-xref>(<var>promise</var>, <var>selfResolutionError</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>If <var>resolution</var> <emu-xref href="#sec-object-type" id="_ref_16021"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, then<ol><li>Perform <emu-xref aoid="FulfillPromise" id="_ref_16022"><a href="control-abstraction-objects.html#sec-fulfillpromise">FulfillPromise</a></emu-xref>(<var>promise</var>, <var>resolution</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>then</var> be <emu-xref aoid="Completion" id="_ref_16023"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Get" id="_ref_16024"><a href="abstract-operations.html#sec-get-o-p" class="e-user-code">Get</a></emu-xref>(<var>resolution</var>, <emu-val>"then"</emu-val>)).</li><li>If <var>then</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16025"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Perform <emu-xref aoid="RejectPromise" id="_ref_16026"><a href="control-abstraction-objects.html#sec-rejectpromise">RejectPromise</a></emu-xref>(<var>promise</var>, <var>then</var>.<var class="field">[[Value]]</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>thenAction</var> be <var>then</var>.<var class="field">[[Value]]</var>.</li><li>If <emu-xref aoid="IsCallable" id="_ref_16027"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>thenAction</var>) is <emu-val>false</emu-val>, then<ol><li>Perform <emu-xref aoid="FulfillPromise" id="_ref_16028"><a href="control-abstraction-objects.html#sec-fulfillpromise">FulfillPromise</a></emu-xref>(<var>promise</var>, <var>resolution</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>thenJobCallback</var> be <emu-xref aoid="HostMakeJobCallback" id="_ref_16029"><a href="executable-code-and-execution-contexts.html#sec-hostmakejobcallback">HostMakeJobCallback</a></emu-xref>(<var>thenAction</var>).</li><li>Let <var>job</var> be <emu-xref aoid="NewPromiseResolveThenableJob" id="_ref_16030"><a href="control-abstraction-objects.html#sec-newpromiseresolvethenablejob">NewPromiseResolveThenableJob</a></emu-xref>(<var>promise</var>, <var>resolution</var>, <var>thenJobCallback</var>).</li><li>Perform <emu-xref aoid="HostEnqueuePromiseJob" id="_ref_16031"><a href="executable-code-and-execution-contexts.html#sec-hostenqueuepromisejob">HostEnqueuePromiseJob</a></emu-xref>(<var>job</var>.<var class="field">[[Job]]</var>, <var>job</var>.<var class="field">[[Realm]]</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>resolve</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16032"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>resolveSteps</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Let <var>rejectSteps</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16033"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>reason</var>) that captures <var>promiseOrEmpty</var> and performs the following steps when called:<ol><li>If <var>promiseOrEmpty</var>.<var class="field">[[Value]]</var> is <emu-const>empty</emu-const>, return <emu-val>undefined</emu-val>.</li><li>Let <var>promise</var> be <var>promiseOrEmpty</var>.<var class="field">[[Value]]</var>.</li><li>Set <var>promiseOrEmpty</var>.<var class="field">[[Value]]</var> to <emu-const>empty</emu-const>.</li><li>Perform <emu-xref aoid="RejectPromise" id="_ref_16034"><a href="control-abstraction-objects.html#sec-rejectpromise">RejectPromise</a></emu-xref>(<var>promise</var>, <var>reason</var>).</li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>reject</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16035"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>rejectSteps</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Return the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16036"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Resolve]]</var>: <var>resolve</var>, <var class="field">[[Reject]]</var>: <var>reject</var>&nbsp;}.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-fulfillpromise" type="abstract operation" aoid="FulfillPromise">
<h1><span class="secnum">27.2.1.4</span> FulfillPromise ( <var>promise</var>, <var>value</var> )</h1>
<p>The abstract operation FulfillPromise takes arguments <var>promise</var> (a Promise) and <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16037"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16038"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>promise</var>.<var class="field">[[PromiseState]]</var> is <emu-const>pending</emu-const>.</li><li>Let <var>reactions</var> be <var>promise</var>.<var class="field">[[PromiseFulfillReactions]]</var>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseResult]]</var> to <var>value</var>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseFulfillReactions]]</var> to <emu-val>undefined</emu-val>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseRejectReactions]]</var> to <emu-val>undefined</emu-val>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseState]]</var> to <emu-const>fulfilled</emu-const>.</li><li>Perform <emu-xref aoid="TriggerPromiseReactions" id="_ref_16039"><a href="control-abstraction-objects.html#sec-triggerpromisereactions">TriggerPromiseReactions</a></emu-xref>(<var>reactions</var>, <var>value</var>).</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-newpromisecapability" type="abstract operation" oldids="sec-getcapabilitiesexecutor-functions" aoid="NewPromiseCapability"><span id="sec-getcapabilitiesexecutor-functions"></span>
<h1><span class="secnum">27.2.1.5</span> NewPromiseCapability ( <var>C</var> )</h1>
<p>The abstract operation NewPromiseCapability takes argument <var>C</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16040"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16041"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> a <emu-xref href="#sec-promisecapability-records" id="_ref_16042"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16043"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It attempts to use <var>C</var> as a <emu-xref href="#constructor" id="_ref_16044"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> in the fashion of the built-in Promise <emu-xref href="#constructor" id="_ref_16045"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to create a promise and extract its <code>resolve</code> and <code>reject</code> functions. The promise plus the <code>resolve</code> and <code>reject</code> functions are used to initialize a new <emu-xref href="#sec-promisecapability-records" id="_ref_16046"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>If <emu-xref aoid="IsConstructor" id="_ref_16047"><a href="abstract-operations.html#sec-isconstructor">IsConstructor</a></emu-xref>(<var>C</var>) is <emu-val>false</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>NOTE: <var>C</var> is assumed to be a <emu-xref href="#constructor" id="_ref_16048"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16049"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> (see <emu-xref href="#sec-promise-executor" id="_ref_827"><a href="control-abstraction-objects.html#sec-promise-executor">27.2.3.1</a></emu-xref>).</li><li>Let <var>resolvingFunctions</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16050"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Resolve]]</var>: <emu-val>undefined</emu-val>, <var class="field">[[Reject]]</var>: <emu-val>undefined</emu-val>&nbsp;}.</li><li>Let <var>executorClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16051"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>resolve</var>, <var>reject</var>) that captures <var>resolvingFunctions</var> and performs the following steps when called:<ol><li>If <var>resolvingFunctions</var>.<var class="field">[[Resolve]]</var> is not <emu-val>undefined</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>If <var>resolvingFunctions</var>.<var class="field">[[Reject]]</var> is not <emu-val>undefined</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Set <var>resolvingFunctions</var>.<var class="field">[[Resolve]]</var> to <var>resolve</var>.</li><li>Set <var>resolvingFunctions</var>.<var class="field">[[Reject]]</var> to <var>reject</var>.</li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16052"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Let <var>executor</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16053"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>executorClosure</var>, 2, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Let <var>promise</var> be ?&nbsp;<emu-xref aoid="Construct" id="_ref_16054"><a href="abstract-operations.html#sec-construct" class="e-user-code">Construct</a></emu-xref>(<var>C</var>, « <var>executor</var>&nbsp;»).</li><li>If <emu-xref aoid="IsCallable" id="_ref_16055"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>resolvingFunctions</var>.<var class="field">[[Resolve]]</var>) is <emu-val>false</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>If <emu-xref aoid="IsCallable" id="_ref_16056"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>resolvingFunctions</var>.<var class="field">[[Reject]]</var>) is <emu-val>false</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Return the <emu-xref href="#sec-promisecapability-records" id="_ref_16057"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref> { <var class="field">[[Promise]]</var>: <var>promise</var>, <var class="field">[[Resolve]]</var>: <var>resolvingFunctions</var>.<var class="field">[[Resolve]]</var>, <var class="field">[[Reject]]</var>: <var>resolvingFunctions</var>.<var class="field">[[Reject]]</var>&nbsp;}.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This abstract operation supports Promise subclassing, as it is generic on any <emu-xref href="#constructor" id="_ref_16058"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> that calls a passed executor function argument in the same way as the Promise <emu-xref href="#constructor" id="_ref_16059"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>. It is used to generalize static methods of the Promise <emu-xref href="#constructor" id="_ref_16060"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to any subclass.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-ispromise" type="abstract operation" aoid="IsPromise">
<h1><span class="secnum">27.2.1.6</span> IsPromise ( <var>x</var> )</h1>
<p>The abstract operation IsPromise takes argument <var>x</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16061"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns a Boolean. It checks for the promise brand on an object. It performs the following steps when called:</p>
<emu-alg><ol><li>If <var>x</var> <emu-xref href="#sec-object-type" id="_ref_16062"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, return <emu-val>false</emu-val>.</li><li>If <var>x</var> does not have a <var class="field">[[PromiseState]]</var> internal slot, return <emu-val>false</emu-val>.</li><li>Return <emu-val>true</emu-val>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-rejectpromise" type="abstract operation" aoid="RejectPromise">
<h1><span class="secnum">27.2.1.7</span> RejectPromise ( <var>promise</var>, <var>reason</var> )</h1>
<p>The abstract operation RejectPromise takes arguments <var>promise</var> (a Promise) and <var>reason</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16063"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16064"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>promise</var>.<var class="field">[[PromiseState]]</var> is <emu-const>pending</emu-const>.</li><li>Let <var>reactions</var> be <var>promise</var>.<var class="field">[[PromiseRejectReactions]]</var>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseResult]]</var> to <var>reason</var>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseFulfillReactions]]</var> to <emu-val>undefined</emu-val>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseRejectReactions]]</var> to <emu-val>undefined</emu-val>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseState]]</var> to <emu-const>rejected</emu-const>.</li><li>If <var>promise</var>.<var class="field">[[PromiseIsHandled]]</var> is <emu-val>false</emu-val>, perform <emu-xref aoid="HostPromiseRejectionTracker" id="_ref_16065"><a href="control-abstraction-objects.html#sec-host-promise-rejection-tracker">HostPromiseRejectionTracker</a></emu-xref>(<var>promise</var>, <emu-val>"reject"</emu-val>).</li><li>Perform <emu-xref aoid="TriggerPromiseReactions" id="_ref_16066"><a href="control-abstraction-objects.html#sec-triggerpromisereactions">TriggerPromiseReactions</a></emu-xref>(<var>reactions</var>, <var>reason</var>).</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-triggerpromisereactions" type="abstract operation" aoid="TriggerPromiseReactions">
<h1><span class="secnum">27.2.1.8</span> TriggerPromiseReactions ( <var>reactions</var>, <var>argument</var> )</h1>
<p>The abstract operation TriggerPromiseReactions takes arguments <var>reactions</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16067"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-xref href="#sec-promisereaction-records" id="_ref_16068"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Records</a></emu-xref>) and <var>argument</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16069"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns <emu-const>unused</emu-const>. It enqueues a new <emu-xref href="#job" id="_ref_16070"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> for each record in <var>reactions</var>. Each such <emu-xref href="#job" id="_ref_16071"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> processes the <var class="field">[[Type]]</var> and <var class="field">[[Handler]]</var> of the <emu-xref href="#sec-promisereaction-records" id="_ref_16072"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Record</a></emu-xref>, and if the <var class="field">[[Handler]]</var> is not <emu-const>empty</emu-const>, calls it passing the given argument. If the <var class="field">[[Handler]]</var> is <emu-const>empty</emu-const>, the behaviour is determined by the <var class="field">[[Type]]</var>. It performs the following steps when called:</p>
<emu-alg><ol><li>For each element <var>reaction</var> of <var>reactions</var>, do<ol><li>Let <var>job</var> be <emu-xref aoid="NewPromiseReactionJob" id="_ref_16073"><a href="control-abstraction-objects.html#sec-newpromisereactionjob">NewPromiseReactionJob</a></emu-xref>(<var>reaction</var>, <var>argument</var>).</li><li>Perform <emu-xref aoid="HostEnqueuePromiseJob" id="_ref_16074"><a href="executable-code-and-execution-contexts.html#sec-hostenqueuepromisejob">HostEnqueuePromiseJob</a></emu-xref>(<var>job</var>.<var class="field">[[Job]]</var>, <var>job</var>.<var class="field">[[Realm]]</var>).</li></ol></li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-host-promise-rejection-tracker" type="host-defined abstract operation" aoid="HostPromiseRejectionTracker">
<h1><span class="secnum">27.2.1.9</span> HostPromiseRejectionTracker ( <var>promise</var>, <var>operation</var> )</h1>
<p>The <emu-xref href="#host-defined" id="_ref_16075"><a href="overview.html#host-defined">host-defined</a></emu-xref> abstract operation HostPromiseRejectionTracker takes arguments <var>promise</var> (a Promise) and <var>operation</var> (<emu-val>"reject"</emu-val> or <emu-val>"handle"</emu-val>) and returns <emu-const>unused</emu-const>. It allows <emu-xref href="#host-environment" id="_ref_16076"><a href="overview.html#host-environment">host environments</a></emu-xref> to track promise rejections.</p>
<p>The default implementation of HostPromiseRejectionTracker is to return <emu-const>unused</emu-const>.</p>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>HostPromiseRejectionTracker is called in two scenarios:</p>
<ul>
<li>When a promise is rejected without any handlers, it is called with its <var>operation</var> argument set to <emu-val>"reject"</emu-val>.</li>
<li>When a handler is added to a rejected promise for the first time, it is called with its <var>operation</var> argument set to <emu-val>"handle"</emu-val>.</li>
</ul>
<p>A typical implementation of HostPromiseRejectionTracker might try to notify developers of unhandled rejections, while also being careful to notify them if such previous notifications are later invalidated by new handlers being attached.</p>
</div></emu-note>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>If <var>operation</var> is <emu-val>"handle"</emu-val>, an implementation should not hold a reference to <var>promise</var> in a way that would interfere with garbage collection. An implementation may hold a reference to <var>promise</var> if <var>operation</var> is <emu-val>"reject"</emu-val>, since it is expected that rejections will be rare and not on hot code paths.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise-jobs">
<h1><span class="secnum">27.2.2</span> Promise Jobs</h1>
<emu-clause id="sec-newpromisereactionjob" type="abstract operation" oldids="sec-promisereactionjob" aoid="NewPromiseReactionJob"><span id="sec-promisereactionjob"></span>
<h1><span class="secnum">27.2.2.1</span> NewPromiseReactionJob ( <var>reaction</var>, <var>argument</var> )</h1>
<p>The abstract operation NewPromiseReactionJob takes arguments <var>reaction</var> (a <emu-xref href="#sec-promisereaction-records" id="_ref_16077"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Record</a></emu-xref>) and <var>argument</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16078"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16079"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> with fields <var class="field">[[Job]]</var> (a <emu-xref href="#job" id="_ref_16080"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> <emu-xref href="#sec-abstract-closure" id="_ref_16081"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref>) and <var class="field">[[Realm]]</var> (a <emu-xref href="#realm-record" id="_ref_16082"><a href="executable-code-and-execution-contexts.html#realm-record">Realm Record</a></emu-xref> or <emu-val>null</emu-val>). It returns a new <emu-xref href="#job" id="_ref_16083"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> <emu-xref href="#sec-abstract-closure" id="_ref_16084"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> that applies the appropriate handler to the incoming value, and uses the handler's return value to resolve or reject the derived promise associated with that handler. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>job</var> be a new <emu-xref href="#job" id="_ref_16085"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> <emu-xref href="#sec-abstract-closure" id="_ref_16086"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>reaction</var> and <var>argument</var> and performs the following steps when called:<ol><li>Let <var>promiseCapability</var> be <var>reaction</var>.<var class="field">[[Capability]]</var>.</li><li>Let <var>type</var> be <var>reaction</var>.<var class="field">[[Type]]</var>.</li><li>Let <var>handler</var> be <var>reaction</var>.<var class="field">[[Handler]]</var>.</li><li>If <var>handler</var> is <emu-const>empty</emu-const>, then<ol><li>If <var>type</var> is <emu-const>fulfill</emu-const>, then<ol><li>Let <var>handlerResult</var> be <emu-xref aoid="NormalCompletion" id="_ref_16087"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>argument</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16088"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>type</var> is <emu-const>reject</emu-const>.</li><li>Let <var>handlerResult</var> be <emu-xref aoid="ThrowCompletion" id="_ref_16089"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>argument</var>).</li></ol></li></ol></li><li>Else,<ol><li>Let <var>handlerResult</var> be <emu-xref aoid="Completion" id="_ref_16090"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="HostCallJobCallback" id="_ref_16091"><a href="executable-code-and-execution-contexts.html#sec-hostcalljobcallback" class="e-user-code">HostCallJobCallback</a></emu-xref>(<var>handler</var>, <emu-val>undefined</emu-val>, « <var>argument</var>&nbsp;»)).</li></ol></li><li>If <var>promiseCapability</var> is <emu-val>undefined</emu-val>, then<ol><li><emu-xref href="#assert" id="_ref_16092"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>handlerResult</var> is not an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16093"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>.</li><li>Return <emu-const>empty</emu-const>.</li></ol></li><li><emu-xref href="#assert" id="_ref_16094"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>promiseCapability</var> is a <emu-xref href="#sec-promisecapability-records" id="_ref_16095"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>.</li><li>If <var>handlerResult</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16096"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16097"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>handlerResult</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16098"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>handlerResult</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Let <var>handlerRealm</var> be <emu-val>null</emu-val>.</li><li>If <var>reaction</var>.<var class="field">[[Handler]]</var> is not <emu-const>empty</emu-const>, then<ol><li>Let <var>getHandlerRealmResult</var> be <emu-xref aoid="Completion" id="_ref_16099"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetFunctionRealm" id="_ref_16100"><a href="abstract-operations.html#sec-getfunctionrealm">GetFunctionRealm</a></emu-xref>(<var>reaction</var>.<var class="field">[[Handler]]</var>.<var class="field">[[Callback]]</var>)).</li><li>If <var>getHandlerRealmResult</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16101"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, set <var>handlerRealm</var> to <var>getHandlerRealmResult</var>.<var class="field">[[Value]]</var>.</li><li>Else, set <var>handlerRealm</var> to <emu-xref href="#current-realm" id="_ref_16102"><a href="executable-code-and-execution-contexts.html#current-realm">the current Realm Record</a></emu-xref>.</li><li>NOTE: <var>handlerRealm</var> is never <emu-val>null</emu-val> unless the handler is <emu-val>undefined</emu-val>. When the handler is a revoked Proxy and no ECMAScript code runs, <var>handlerRealm</var> is used to create error objects.</li></ol></li><li>Return the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16103"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Job]]</var>: <var>job</var>, <var class="field">[[Realm]]</var>: <var>handlerRealm</var>&nbsp;}.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-newpromiseresolvethenablejob" type="abstract operation" oldids="sec-promiseresolvethenablejob" aoid="NewPromiseResolveThenableJob"><span id="sec-promiseresolvethenablejob"></span>
<h1><span class="secnum">27.2.2.2</span> NewPromiseResolveThenableJob ( <var>promiseToResolve</var>, <var>thenable</var>, <var>then</var> )</h1>
<p>The abstract operation NewPromiseResolveThenableJob takes arguments <var>promiseToResolve</var> (a Promise), <var>thenable</var> (an Object), and <var>then</var> (a <emu-xref href="#sec-jobcallback-records" id="_ref_16104"><a href="executable-code-and-execution-contexts.html#sec-jobcallback-records">JobCallback Record</a></emu-xref>) and returns a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16105"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> with fields <var class="field">[[Job]]</var> (a <emu-xref href="#job" id="_ref_16106"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> <emu-xref href="#sec-abstract-closure" id="_ref_16107"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref>) and <var class="field">[[Realm]]</var> (a <emu-xref href="#realm-record" id="_ref_16108"><a href="executable-code-and-execution-contexts.html#realm-record">Realm Record</a></emu-xref>). It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>job</var> be a new <emu-xref href="#job" id="_ref_16109"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> <emu-xref href="#sec-abstract-closure" id="_ref_16110"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>promiseToResolve</var>, <var>thenable</var>, and <var>then</var> and performs the following steps when called:<ol><li>Let <var>resolvingFunctions</var> be <emu-xref aoid="CreateResolvingFunctions" id="_ref_16111"><a href="control-abstraction-objects.html#sec-createresolvingfunctions">CreateResolvingFunctions</a></emu-xref>(<var>promiseToResolve</var>).</li><li>Let <var>thenCallResult</var> be <emu-xref aoid="Completion" id="_ref_16112"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="HostCallJobCallback" id="_ref_16113"><a href="executable-code-and-execution-contexts.html#sec-hostcalljobcallback" class="e-user-code">HostCallJobCallback</a></emu-xref>(<var>then</var>, <var>thenable</var>, « <var>resolvingFunctions</var>.<var class="field">[[Resolve]]</var>, <var>resolvingFunctions</var>.<var class="field">[[Reject]]</var>&nbsp;»)).</li><li>If <var>thenCallResult</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16114"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16115"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resolvingFunctions</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>thenCallResult</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Return !&nbsp;<var>thenCallResult</var>.</li></ol></li><li>Let <var>getThenRealmResult</var> be <emu-xref aoid="Completion" id="_ref_16116"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetFunctionRealm" id="_ref_16117"><a href="abstract-operations.html#sec-getfunctionrealm">GetFunctionRealm</a></emu-xref>(<var>then</var>.<var class="field">[[Callback]]</var>)).</li><li>If <var>getThenRealmResult</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16118"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, let <var>thenRealm</var> be <var>getThenRealmResult</var>.<var class="field">[[Value]]</var>.</li><li>Else, let <var>thenRealm</var> be <emu-xref href="#current-realm" id="_ref_16119"><a href="executable-code-and-execution-contexts.html#current-realm">the current Realm Record</a></emu-xref>.</li><li>NOTE: <var>thenRealm</var> is never <emu-val>null</emu-val>. When <var>then</var>.<var class="field">[[Callback]]</var> is a revoked Proxy and no code runs, <var>thenRealm</var> is used to create error objects.</li><li>Return the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16120"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Job]]</var>: <var>job</var>, <var class="field">[[Realm]]</var>: <var>thenRealm</var>&nbsp;}.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This <emu-xref href="#job" id="_ref_16121"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> uses the supplied thenable and its <code>then</code> method to resolve the given promise. This process must take place as a <emu-xref href="#job" id="_ref_16122"><a href="executable-code-and-execution-contexts.html#job">Job</a></emu-xref> to ensure that the evaluation of the <code>then</code> method occurs after evaluation of any surrounding code has completed.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise-constructor">
<h1><span class="secnum">27.2.3</span> The Promise Constructor</h1>
<p>The Promise <emu-xref href="#constructor" id="_ref_16123"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is <dfn tabindex="-1">%Promise%</dfn>.</li>
<li>is the initial value of the <emu-val>"Promise"</emu-val> property of the <emu-xref href="#sec-global-object" id="_ref_16124"><a href="global-object.html#sec-global-object">global object</a></emu-xref>.</li>
<li>creates and initializes a new Promise when called as a <emu-xref href="#constructor" id="_ref_16125"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</li>
<li>is not intended to be called as a function and will throw an exception when called in that manner.</li>
<li>may be used as the value in an <code>extends</code> clause of a class definition. Subclass <emu-xref href="#constructor" id="_ref_16126"><a href="ecmascript-data-types-and-values.html#constructor">constructors</a></emu-xref> that intend to inherit the specified Promise behaviour must include a <code>super</code> call to the Promise <emu-xref href="#constructor" id="_ref_16127"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to create and initialize the subclass instance with the internal state necessary to support the <code>Promise</code> and <code>Promise.prototype</code> built-in methods.</li>
</ul>
<emu-clause id="sec-promise-executor" type="built-in function">
<h1><span class="secnum">27.2.3.1</span> Promise ( <var>executor</var> )</h1>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>If NewTarget is <emu-val>undefined</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>If <emu-xref aoid="IsCallable" id="_ref_16128"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>executor</var>) is <emu-val>false</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>promise</var> be ?&nbsp;<emu-xref aoid="OrdinaryCreateFromConstructor" id="_ref_16129"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinarycreatefromconstructor" class="e-user-code">OrdinaryCreateFromConstructor</a></emu-xref>(NewTarget, <emu-val>"%Promise.prototype%"</emu-val>, « <var class="field">[[PromiseState]]</var>, <var class="field">[[PromiseResult]]</var>, <var class="field">[[PromiseFulfillReactions]]</var>, <var class="field">[[PromiseRejectReactions]]</var>, <var class="field">[[PromiseIsHandled]]</var>&nbsp;»).</li><li>Set <var>promise</var>.<var class="field">[[PromiseState]]</var> to <emu-const>pending</emu-const>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseResult]]</var> to <emu-const>empty</emu-const>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseFulfillReactions]]</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16130"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseRejectReactions]]</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16131"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Set <var>promise</var>.<var class="field">[[PromiseIsHandled]]</var> to <emu-val>false</emu-val>.</li><li>Let <var>resolvingFunctions</var> be <emu-xref aoid="CreateResolvingFunctions" id="_ref_16132"><a href="control-abstraction-objects.html#sec-createresolvingfunctions">CreateResolvingFunctions</a></emu-xref>(<var>promise</var>).</li><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_16133"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_16134"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>executor</var>, <emu-val>undefined</emu-val>, « <var>resolvingFunctions</var>.<var class="field">[[Resolve]]</var>, <var>resolvingFunctions</var>.<var class="field">[[Reject]]</var>&nbsp;»)).</li><li>If <var>completion</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16135"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16136"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resolvingFunctions</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>completion</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Return <var>promise</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>The <var>executor</var> argument must be a <emu-xref href="#function-object" id="_ref_16137"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>. It is called for initiating and reporting completion of the possibly deferred action represented by this Promise. The executor is called with two arguments: <var>resolve</var> and <var>reject</var>. These are functions that may be used by the <var>executor</var> function to report eventual completion or failure of the deferred computation. Returning from the executor function does not mean that the deferred action has been completed but only that the request to eventually perform the deferred action has been accepted.</p>
<p>The <var>resolve</var> function that is passed to an <var>executor</var> function accepts a single argument. The <var>executor</var> code may eventually call the <var>resolve</var> function to indicate that it wishes to resolve the associated Promise. The argument passed to the <var>resolve</var> function represents the eventual value of the deferred action and can be either the actual fulfillment value or another promise which will provide the value if it is fulfilled.</p>
<p>The <var>reject</var> function that is passed to an <var>executor</var> function accepts a single argument. The <var>executor</var> code may eventually call the <var>reject</var> function to indicate that the associated Promise is rejected and will never be fulfilled. The argument passed to the <var>reject</var> function is used as the rejection value of the promise. Typically it will be an Error object.</p>
<p>The resolve and reject functions passed to an <var>executor</var> function by the Promise <emu-xref href="#constructor" id="_ref_16138"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> have the capability to actually resolve and reject the associated promise. Subclasses may have different <emu-xref href="#constructor" id="_ref_16139"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> behaviour that passes in customized values for resolve and reject.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-the-promise-constructor">
<h1><span class="secnum">27.2.4</span> Properties of the Promise Constructor</h1>
<p>The Promise <emu-xref href="#constructor" id="_ref_16140"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-function-prototype-object" id="_ref_16141"><a href="fundamental-objects.html#sec-properties-of-the-function-prototype-object">%Function.prototype%</a></emu-xref>.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-promise.all" type="built-in function">
<h1><span class="secnum">27.2.4.1</span> Promise.all ( <var>iterable</var> )</h1>
<p>This function returns a new promise which is fulfilled with an array of fulfillment values for the passed promises, or rejects with the reason of the first passed promise that rejects. It resolves all elements of the passed <emu-xref href="#sec-iterable-interface" id="_ref_16142"><a href="control-abstraction-objects.html#sec-iterable-interface">iterable</a></emu-xref> to promises as it runs this algorithm.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16143"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Let <var>promiseResolve</var> be <emu-xref aoid="Completion" id="_ref_16144"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetPromiseResolve" id="_ref_16145"><a href="control-abstraction-objects.html#sec-getpromiseresolve" class="e-user-code">GetPromiseResolve</a></emu-xref>(<var>C</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16146"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>promiseResolve</var>, <var>promiseCapability</var>).</li><li>Let <var>iteratorRecord</var> be <emu-xref aoid="Completion" id="_ref_16147"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetIterator" id="_ref_16148"><a href="abstract-operations.html#sec-getiterator" class="e-user-code">GetIterator</a></emu-xref>(<var>iterable</var>, <emu-const>sync</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16149"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>iteratorRecord</var>, <var>promiseCapability</var>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16150"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PerformPromiseAll" id="_ref_16151"><a href="control-abstraction-objects.html#sec-performpromiseall">PerformPromiseAll</a></emu-xref>(<var>iteratorRecord</var>, <var>C</var>, <var>promiseCapability</var>, <var>promiseResolve</var>)).</li><li>If <var>result</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16152"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>If <var>iteratorRecord</var>.<var class="field">[[Done]]</var> is <emu-val>false</emu-val>, set <var>result</var> to <emu-xref aoid="Completion" id="_ref_16153"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_16154"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>result</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16155"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li></ol></li><li>Return !&nbsp;<var>result</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This function requires its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16156"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16157"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
</div></emu-note>
<emu-clause id="sec-getpromiseresolve" type="abstract operation" aoid="GetPromiseResolve">
<h1><span class="secnum">27.2.4.1.1</span> GetPromiseResolve ( <var>promiseConstructor</var> )</h1>
<p>The abstract operation GetPromiseResolve takes argument <var>promiseConstructor</var> (a <emu-xref href="#constructor" id="_ref_16158"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16159"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> a <emu-xref href="#function-object" id="_ref_16160"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16161"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>promiseResolve</var> be ?&nbsp;<emu-xref aoid="Get" id="_ref_16162"><a href="abstract-operations.html#sec-get-o-p" class="e-user-code">Get</a></emu-xref>(<var>promiseConstructor</var>, <emu-val>"resolve"</emu-val>).</li><li>If <emu-xref aoid="IsCallable" id="_ref_16163"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>promiseResolve</var>) is <emu-val>false</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Return <var>promiseResolve</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-performpromiseall" oldids="sec-promise.all-resolve-element-functions" type="abstract operation" aoid="PerformPromiseAll"><span id="sec-promise.all-resolve-element-functions"></span>
<h1><span class="secnum">27.2.4.1.2</span> PerformPromiseAll ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</h1>
<p>The abstract operation PerformPromiseAll takes arguments <var>iteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_16164"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>), <var>constructor</var> (a <emu-xref href="#constructor" id="_ref_16165"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>), <var>resultCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16166"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>), and <var>promiseResolve</var> (a <emu-xref href="#function-object" id="_ref_16167"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16168"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16169"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16170"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>values</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16171"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li declared="remainingElementsCount">NOTE: <var>remainingElementsCount</var> starts at 1 instead of 0 to ensure <var>resultCapability</var>.<var class="field">[[Resolve]]</var> is only called once, even in the presence of a misbehaving <emu-val>"then"</emu-val> which calls the passed callback before the input <emu-xref href="#sec-iterator-interface" id="_ref_16172"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> is exhausted.</li><li>Let <var>remainingElementsCount</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16173"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Value]]</var>: 1&nbsp;}.</li><li>Let <var>index</var> be 0.</li><li>Repeat,<ol><li>Let <var>next</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_16174"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iteratorRecord</var>).</li><li>If <var>next</var> is <emu-const>done</emu-const>, then<ol><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>valuesArray</var> be <emu-xref aoid="CreateArrayFromList" id="_ref_16175"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>values</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16176"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>valuesArray</var>&nbsp;»).</li></ol></li><li>Return <var>resultCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Append <emu-val>undefined</emu-val> to <var>values</var>.</li><li>Let <var>nextPromise</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_16177"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseResolve</var>, <var>constructor</var>, « <var>next</var>&nbsp;»).</li><li>Let <var>fulfilledSteps</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16178"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>value</var>) that captures <var>values</var>, <var>resultCapability</var>, and <var>remainingElementsCount</var> and performs the following steps when called:<ol><li>Let <var>F</var> be the <emu-xref href="#active-function-object" id="_ref_16179"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>F</var>.<var class="field">[[AlreadyCalled]]</var> is <emu-val>true</emu-val>, return <emu-val>undefined</emu-val>.</li><li>Set <var>F</var>.<var class="field">[[AlreadyCalled]]</var> to <emu-val>true</emu-val>.</li><li>Let <var>thisIndex</var> be <var>F</var>.<var class="field">[[Index]]</var>.</li><li>Set <var>values</var>[<var>thisIndex</var>] to <var>value</var>.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>valuesArray</var> be <emu-xref aoid="CreateArrayFromList" id="_ref_16180"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>values</var>).</li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16181"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>valuesArray</var>&nbsp;»).</li></ol></li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>onFulfilled</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16182"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>fulfilledSteps</var>, 1, <emu-val>""</emu-val>, « <var class="field">[[AlreadyCalled]]</var>, <var class="field">[[Index]]</var>&nbsp;»).</li><li>Set <var>onFulfilled</var>.<var class="field">[[AlreadyCalled]]</var> to <emu-val>false</emu-val>.</li><li>Set <var>onFulfilled</var>.<var class="field">[[Index]]</var> to <var>index</var>.</li><li>Set <var>index</var> to <var>index</var> + 1.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> + 1.</li><li>Perform ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16183"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>nextPromise</var>, <emu-val>"then"</emu-val>, « <var>onFulfilled</var>, <var>resultCapability</var>.<var class="field">[[Reject]]</var>&nbsp;»).</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise.allsettled" type="built-in function">
<h1><span class="secnum">27.2.4.2</span> Promise.allSettled ( <var>iterable</var> )</h1>
<p>This function returns a promise that is fulfilled with an array of promise state snapshots, but only after all the original promises have settled, i.e. become either fulfilled or rejected. It resolves all elements of the passed <emu-xref href="#sec-iterable-interface" id="_ref_16184"><a href="control-abstraction-objects.html#sec-iterable-interface">iterable</a></emu-xref> to promises as it runs this algorithm.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16185"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Let <var>promiseResolve</var> be <emu-xref aoid="Completion" id="_ref_16186"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetPromiseResolve" id="_ref_16187"><a href="control-abstraction-objects.html#sec-getpromiseresolve" class="e-user-code">GetPromiseResolve</a></emu-xref>(<var>C</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16188"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>promiseResolve</var>, <var>promiseCapability</var>).</li><li>Let <var>iteratorRecord</var> be <emu-xref aoid="Completion" id="_ref_16189"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetIterator" id="_ref_16190"><a href="abstract-operations.html#sec-getiterator" class="e-user-code">GetIterator</a></emu-xref>(<var>iterable</var>, <emu-const>sync</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16191"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>iteratorRecord</var>, <var>promiseCapability</var>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16192"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PerformPromiseAllSettled" id="_ref_16193"><a href="control-abstraction-objects.html#sec-performpromiseallsettled">PerformPromiseAllSettled</a></emu-xref>(<var>iteratorRecord</var>, <var>C</var>, <var>promiseCapability</var>, <var>promiseResolve</var>)).</li><li>If <var>result</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16194"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>If <var>iteratorRecord</var>.<var class="field">[[Done]]</var> is <emu-val>false</emu-val>, set <var>result</var> to <emu-xref aoid="Completion" id="_ref_16195"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_16196"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>result</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16197"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li></ol></li><li>Return !&nbsp;<var>result</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This function requires its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16198"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16199"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
</div></emu-note>
<emu-clause id="sec-performpromiseallsettled" oldids="sec-promise.allsettled-resolve-element-functions,sec-promise.allsettled-reject-element-functions" type="abstract operation" aoid="PerformPromiseAllSettled"><span id="sec-promise.allsettled-reject-element-functions"></span><span id="sec-promise.allsettled-resolve-element-functions"></span>
<h1><span class="secnum">27.2.4.2.1</span> PerformPromiseAllSettled ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</h1>
<p>The abstract operation PerformPromiseAllSettled takes arguments <var>iteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_16200"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>), <var>constructor</var> (a <emu-xref href="#constructor" id="_ref_16201"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>), <var>resultCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16202"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>), and <var>promiseResolve</var> (a <emu-xref href="#function-object" id="_ref_16203"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16204"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16205"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16206"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>values</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16207"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li declared="remainingElementsCount">NOTE: <var>remainingElementsCount</var> starts at 1 instead of 0 to ensure <var>resultCapability</var>.<var class="field">[[Resolve]]</var> is only called once, even in the presence of a misbehaving <emu-val>"then"</emu-val> which calls one of the passed callbacks before the input <emu-xref href="#sec-iterator-interface" id="_ref_16208"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> is exhausted.</li><li>Let <var>remainingElementsCount</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16209"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Value]]</var>: 1&nbsp;}.</li><li>Let <var>index</var> be 0.</li><li>Repeat,<ol><li>Let <var>next</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_16210"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iteratorRecord</var>).</li><li>If <var>next</var> is <emu-const>done</emu-const>, then<ol><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>valuesArray</var> be <emu-xref aoid="CreateArrayFromList" id="_ref_16211"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>values</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16212"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>valuesArray</var>&nbsp;»).</li></ol></li><li>Return <var>resultCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Append <emu-val>undefined</emu-val> to <var>values</var>.</li><li>Let <var>nextPromise</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_16213"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseResolve</var>, <var>constructor</var>, « <var>next</var>&nbsp;»).</li><li>Let <var>alreadyCalled</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16214"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Value]]</var>: <emu-val>false</emu-val>&nbsp;}.</li><li>Let <var>fulfilledSteps</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16215"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>value</var>) that captures <var>values</var>, <var>resultCapability</var>, and <var>remainingElementsCount</var> and performs the following steps when called:<ol><li>Let <var>F</var> be the <emu-xref href="#active-function-object" id="_ref_16216"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>F</var>.<var class="field">[[AlreadyCalled]]</var>.<var class="field">[[Value]]</var> is <emu-val>true</emu-val>, return <emu-val>undefined</emu-val>.</li><li>Set <var>F</var>.<var class="field">[[AlreadyCalled]]</var>.<var class="field">[[Value]]</var> to <emu-val>true</emu-val>.</li><li>Let <var>obj</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_16217"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<emu-xref href="#sec-properties-of-the-object-prototype-object" id="_ref_16218"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16219"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"status"</emu-val>, <emu-val>"fulfilled"</emu-val>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16220"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"value"</emu-val>, <var>value</var>).</li><li>Let <var>thisIndex</var> be <var>F</var>.<var class="field">[[Index]]</var>.</li><li>Set <var>values</var>[<var>thisIndex</var>] to <var>obj</var>.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>valuesArray</var> be <emu-xref aoid="CreateArrayFromList" id="_ref_16221"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>values</var>).</li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16222"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>valuesArray</var>&nbsp;»).</li></ol></li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>onFulfilled</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16223"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>fulfilledSteps</var>, 1, <emu-val>""</emu-val>, « <var class="field">[[AlreadyCalled]]</var>, <var class="field">[[Index]]</var>&nbsp;»).</li><li>Set <var>onFulfilled</var>.<var class="field">[[AlreadyCalled]]</var> to <var>alreadyCalled</var>.</li><li>Set <var>onFulfilled</var>.<var class="field">[[Index]]</var> to <var>index</var>.</li><li>Let <var>rejectedSteps</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16224"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>error</var>) that captures <var>values</var>, <var>resultCapability</var>, and <var>remainingElementsCount</var> and performs the following steps when called:<ol><li>Let <var>F</var> be the <emu-xref href="#active-function-object" id="_ref_16225"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>F</var>.<var class="field">[[AlreadyCalled]]</var>.<var class="field">[[Value]]</var> is <emu-val>true</emu-val>, return <emu-val>undefined</emu-val>.</li><li>Set <var>F</var>.<var class="field">[[AlreadyCalled]]</var>.<var class="field">[[Value]]</var> to <emu-val>true</emu-val>.</li><li>Let <var>obj</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_16226"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<emu-xref href="#sec-properties-of-the-object-prototype-object" id="_ref_16227"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16228"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"status"</emu-val>, <emu-val>"rejected"</emu-val>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16229"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"reason"</emu-val>, <var>error</var>).</li><li>Let <var>thisIndex</var> be <var>F</var>.<var class="field">[[Index]]</var>.</li><li>Set <var>values</var>[<var>thisIndex</var>] to <var>obj</var>.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>valuesArray</var> be <emu-xref aoid="CreateArrayFromList" id="_ref_16230"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>values</var>).</li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16231"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>valuesArray</var>&nbsp;»).</li></ol></li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>onRejected</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16232"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>rejectedSteps</var>, 1, <emu-val>""</emu-val>, « <var class="field">[[AlreadyCalled]]</var>, <var class="field">[[Index]]</var>&nbsp;»).</li><li>Set <var>onRejected</var>.<var class="field">[[AlreadyCalled]]</var> to <var>alreadyCalled</var>.</li><li>Set <var>onRejected</var>.<var class="field">[[Index]]</var> to <var>index</var>.</li><li>Set <var>index</var> to <var>index</var> + 1.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> + 1.</li><li>Perform ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16233"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>nextPromise</var>, <emu-val>"then"</emu-val>, « <var>onFulfilled</var>, <var>onRejected</var>&nbsp;»).</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise.any" type="built-in function">
<h1><span class="secnum">27.2.4.3</span> Promise.any ( <var>iterable</var> )</h1>
<p>This function returns a promise that is fulfilled by the first given promise to be fulfilled, or rejected with an <code>AggregateError</code> holding the rejection reasons if all of the given promises are rejected. It resolves all elements of the passed <emu-xref href="#sec-iterable-interface" id="_ref_16234"><a href="control-abstraction-objects.html#sec-iterable-interface">iterable</a></emu-xref> to promises as it runs this algorithm.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16235"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Let <var>promiseResolve</var> be <emu-xref aoid="Completion" id="_ref_16236"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetPromiseResolve" id="_ref_16237"><a href="control-abstraction-objects.html#sec-getpromiseresolve" class="e-user-code">GetPromiseResolve</a></emu-xref>(<var>C</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16238"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>promiseResolve</var>, <var>promiseCapability</var>).</li><li>Let <var>iteratorRecord</var> be <emu-xref aoid="Completion" id="_ref_16239"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetIterator" id="_ref_16240"><a href="abstract-operations.html#sec-getiterator" class="e-user-code">GetIterator</a></emu-xref>(<var>iterable</var>, <emu-const>sync</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16241"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>iteratorRecord</var>, <var>promiseCapability</var>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16242"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PerformPromiseAny" id="_ref_16243"><a href="control-abstraction-objects.html#sec-performpromiseany">PerformPromiseAny</a></emu-xref>(<var>iteratorRecord</var>, <var>C</var>, <var>promiseCapability</var>, <var>promiseResolve</var>)).</li><li>If <var>result</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16244"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>If <var>iteratorRecord</var>.<var class="field">[[Done]]</var> is <emu-val>false</emu-val>, set <var>result</var> to <emu-xref aoid="Completion" id="_ref_16245"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_16246"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>result</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16247"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li></ol></li><li>Return !&nbsp;<var>result</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This function requires its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16248"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the <code>Promise</code> <emu-xref href="#constructor" id="_ref_16249"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
</div></emu-note>
<emu-clause id="sec-performpromiseany" oldids="sec-promise.any-reject-element-functions" type="abstract operation" aoid="PerformPromiseAny"><span id="sec-promise.any-reject-element-functions"></span>
<h1><span class="secnum">27.2.4.3.1</span> PerformPromiseAny ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</h1>
<p>The abstract operation PerformPromiseAny takes arguments <var>iteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_16250"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>), <var>constructor</var> (a <emu-xref href="#constructor" id="_ref_16251"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>), <var>resultCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16252"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>), and <var>promiseResolve</var> (a <emu-xref href="#function-object" id="_ref_16253"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16254"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16255"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16256"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>errors</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16257"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li declared="remainingElementsCount">NOTE: <var>remainingElementsCount</var> starts at 1 instead of 0 to ensure <var>resultCapability</var>.<var class="field">[[Reject]]</var> is only called once, even in the presence of a misbehaving <emu-val>"then"</emu-val> which calls the passed callback before the input <emu-xref href="#sec-iterator-interface" id="_ref_16258"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> is exhausted.</li><li>Let <var>remainingElementsCount</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16259"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> { <var class="field">[[Value]]</var>: 1&nbsp;}.</li><li>Let <var>index</var> be 0.</li><li>Repeat,<ol><li>Let <var>next</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_16260"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iteratorRecord</var>).</li><li>If <var>next</var> is <emu-const>done</emu-const>, then<ol><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>aggregateError</var> be a newly created <emu-val>AggregateError</emu-val> object.</li><li>Perform !&nbsp;<emu-xref aoid="DefinePropertyOrThrow" id="_ref_16261"><a href="abstract-operations.html#sec-definepropertyorthrow">DefinePropertyOrThrow</a></emu-xref>(<var>aggregateError</var>, <emu-val>"errors"</emu-val>, PropertyDescriptor { <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Writable]]</var>: <emu-val>true</emu-val>, <var class="field">[[Value]]</var>: <emu-xref aoid="CreateArrayFromList" id="_ref_16262"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>errors</var>)&nbsp;}).</li><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16263"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>aggregateError</var>&nbsp;»).</li></ol></li><li>Return <var>resultCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Append <emu-val>undefined</emu-val> to <var>errors</var>.</li><li>Let <var>nextPromise</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_16264"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseResolve</var>, <var>constructor</var>, « <var>next</var>&nbsp;»).</li><li>Let <var>rejectedSteps</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16265"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>error</var>) that captures <var>errors</var>, <var>resultCapability</var>, and <var>remainingElementsCount</var> and performs the following steps when called:<ol><li>Let <var>F</var> be the <emu-xref href="#active-function-object" id="_ref_16266"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>F</var>.<var class="field">[[AlreadyCalled]]</var> is <emu-val>true</emu-val>, return <emu-val>undefined</emu-val>.</li><li>Set <var>F</var>.<var class="field">[[AlreadyCalled]]</var> to <emu-val>true</emu-val>.</li><li>Let <var>thisIndex</var> be <var>F</var>.<var class="field">[[Index]]</var>.</li><li>Set <var>errors</var>[<var>thisIndex</var>] to <var>error</var>.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> - 1.</li><li>If <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> = 0, then<ol><li>Let <var>aggregateError</var> be a newly created <emu-val>AggregateError</emu-val> object.</li><li>Perform !&nbsp;<emu-xref aoid="DefinePropertyOrThrow" id="_ref_16267"><a href="abstract-operations.html#sec-definepropertyorthrow">DefinePropertyOrThrow</a></emu-xref>(<var>aggregateError</var>, <emu-val>"errors"</emu-val>, PropertyDescriptor { <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Writable]]</var>: <emu-val>true</emu-val>, <var class="field">[[Value]]</var>: <emu-xref aoid="CreateArrayFromList" id="_ref_16268"><a href="abstract-operations.html#sec-createarrayfromlist">CreateArrayFromList</a></emu-xref>(<var>errors</var>)&nbsp;}).</li><li>Return ?&nbsp;<emu-xref aoid="Call" id="_ref_16269"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>resultCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>aggregateError</var>&nbsp;»).</li></ol></li><li>Return <emu-val>undefined</emu-val>.</li></ol></li><li>Let <var>onRejected</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16270"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>rejectedSteps</var>, 1, <emu-val>""</emu-val>, « <var class="field">[[AlreadyCalled]]</var>, <var class="field">[[Index]]</var>&nbsp;»).</li><li>Set <var>onRejected</var>.<var class="field">[[AlreadyCalled]]</var> to <emu-val>false</emu-val>.</li><li>Set <var>onRejected</var>.<var class="field">[[Index]]</var> to <var>index</var>.</li><li>Set <var>index</var> to <var>index</var> + 1.</li><li>Set <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> to <var>remainingElementsCount</var>.<var class="field">[[Value]]</var> + 1.</li><li>Perform ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16271"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>nextPromise</var>, <emu-val>"then"</emu-val>, « <var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <var>onRejected</var>&nbsp;»).</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise.prototype">
<h1><span class="secnum">27.2.4.4</span> Promise.prototype</h1>
<p>The initial value of <code>Promise.prototype</code> is the <emu-xref href="#sec-properties-of-the-promise-prototype-object" id="_ref_16272"><a href="control-abstraction-objects.html#sec-properties-of-the-promise-prototype-object">Promise prototype object</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
</emu-clause>
<emu-clause id="sec-promise.race" type="built-in function">
<h1><span class="secnum">27.2.4.5</span> Promise.race ( <var>iterable</var> )</h1>
<p>This function returns a new promise which is settled in the same way as the first passed promise to settle. It resolves all elements of the passed <var>iterable</var> to promises as it runs this algorithm.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16273"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Let <var>promiseResolve</var> be <emu-xref aoid="Completion" id="_ref_16274"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetPromiseResolve" id="_ref_16275"><a href="control-abstraction-objects.html#sec-getpromiseresolve" class="e-user-code">GetPromiseResolve</a></emu-xref>(<var>C</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16276"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>promiseResolve</var>, <var>promiseCapability</var>).</li><li>Let <var>iteratorRecord</var> be <emu-xref aoid="Completion" id="_ref_16277"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="GetIterator" id="_ref_16278"><a href="abstract-operations.html#sec-getiterator" class="e-user-code">GetIterator</a></emu-xref>(<var>iterable</var>, <emu-const>sync</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16279"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>iteratorRecord</var>, <var>promiseCapability</var>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16280"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PerformPromiseRace" id="_ref_16281"><a href="control-abstraction-objects.html#sec-performpromiserace" class="e-user-code">PerformPromiseRace</a></emu-xref>(<var>iteratorRecord</var>, <var>C</var>, <var>promiseCapability</var>, <var>promiseResolve</var>)).</li><li>If <var>result</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16282"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>If <var>iteratorRecord</var>.<var class="field">[[Done]]</var> is <emu-val>false</emu-val>, set <var>result</var> to <emu-xref aoid="Completion" id="_ref_16283"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="IteratorClose" id="_ref_16284"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>result</var>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16285"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li></ol></li><li>Return !&nbsp;<var>result</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>If the <var>iterable</var> argument yields no values or if none of the promises yielded by <var>iterable</var> ever settle, then the pending promise returned by this method will never be settled.</p>
</div></emu-note>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>This function expects its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16286"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16287"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>. It also expects that its <emu-val>this</emu-val> value provides a <code>resolve</code> method.</p>
</div></emu-note>
<emu-clause id="sec-performpromiserace" type="abstract operation" aoid="PerformPromiseRace">
<h1><span class="secnum">27.2.4.5.1</span> PerformPromiseRace ( <var>iteratorRecord</var>, <var>constructor</var>, <var>resultCapability</var>, <var>promiseResolve</var> )</h1>
<p>The abstract operation PerformPromiseRace takes arguments <var>iteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_16288"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>), <var>constructor</var> (a <emu-xref href="#constructor" id="_ref_16289"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>), <var>resultCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16290"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>), and <var>promiseResolve</var> (a <emu-xref href="#function-object" id="_ref_16291"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16292"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16293"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16294"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Repeat,<ol><li>Let <var>next</var> be ?&nbsp;<emu-xref aoid="IteratorStepValue" id="_ref_16295"><a href="abstract-operations.html#sec-iteratorstepvalue" class="e-user-code">IteratorStepValue</a></emu-xref>(<var>iteratorRecord</var>).</li><li>If <var>next</var> is <emu-const>done</emu-const>, then<ol><li>Return <var>resultCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Let <var>nextPromise</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_16296"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseResolve</var>, <var>constructor</var>, « <var>next</var>&nbsp;»).</li><li>Perform ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16297"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>nextPromise</var>, <emu-val>"then"</emu-val>, « <var>resultCapability</var>.<var class="field">[[Resolve]]</var>, <var>resultCapability</var>.<var class="field">[[Reject]]</var>&nbsp;»).</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise.reject" type="built-in function">
<h1><span class="secnum">27.2.4.6</span> Promise.reject ( <var>r</var> )</h1>
<p>This function returns a new promise rejected with the passed argument.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16298"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16299"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>r</var>&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This function expects its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16300"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16301"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-promise.resolve" type="built-in function">
<h1><span class="secnum">27.2.4.7</span> Promise.resolve ( <var>x</var> )</h1>
<p>This function returns either a new promise resolved with the passed argument, or the argument itself if the argument is a promise produced by this <emu-xref href="#constructor" id="_ref_16302"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>If <var>C</var> <emu-xref href="#sec-object-type" id="_ref_16303"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Return ?&nbsp;<emu-xref aoid="PromiseResolve" id="_ref_16304"><a href="control-abstraction-objects.html#sec-promise-resolve" class="e-user-code">PromiseResolve</a></emu-xref>(<var>C</var>, <var>x</var>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This function expects its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16305"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16306"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
</div></emu-note>
<emu-clause id="sec-promise-resolve" type="abstract operation" aoid="PromiseResolve">
<h1><span class="secnum">27.2.4.7.1</span> PromiseResolve ( <var>C</var>, <var>x</var> )</h1>
<p>The abstract operation PromiseResolve takes arguments <var>C</var> (an Object) and <var>x</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16307"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16308"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16309"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16310"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It returns a new promise resolved with <var>x</var>. It performs the following steps when called:</p>
<emu-alg><ol><li>If <emu-xref aoid="IsPromise" id="_ref_16311"><a href="control-abstraction-objects.html#sec-ispromise">IsPromise</a></emu-xref>(<var>x</var>) is <emu-val>true</emu-val>, then<ol><li>Let <var>xConstructor</var> be ?&nbsp;<emu-xref aoid="Get" id="_ref_16312"><a href="abstract-operations.html#sec-get-o-p" class="e-user-code">Get</a></emu-xref>(<var>x</var>, <emu-val>"constructor"</emu-val>).</li><li>If <emu-xref aoid="SameValue" id="_ref_16313"><a href="abstract-operations.html#sec-samevalue">SameValue</a></emu-xref>(<var>xConstructor</var>, <var>C</var>) is <emu-val>true</emu-val>, return <var>x</var>.</li></ol></li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16314"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16315"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>x</var>&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-promise.try" type="built-in function">
<h1><span class="secnum">27.2.4.8</span> Promise.try ( <var>callback</var>, ...<var>args</var> )</h1>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>If <var>C</var> <emu-xref href="#sec-object-type" id="_ref_16316"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16317"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_16318"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Call" id="_ref_16319"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>callback</var>, <emu-val>undefined</emu-val>, <var>args</var>)).</li><li>If <var>status</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16320"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16321"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>status</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Else,<ol><li>Perform ?&nbsp;<emu-xref aoid="Call" id="_ref_16322"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>status</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This function expects its <emu-val>this</emu-val> value to be a <emu-xref href="#constructor" id="_ref_16323"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> function that supports the parameter conventions of the Promise <emu-xref href="#constructor" id="_ref_16324"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-promise.withResolvers" type="built-in function">
<h1><span class="secnum">27.2.4.9</span> Promise.withResolvers ( )</h1>
<p>This function returns an object with three properties: a new promise together with the <code>resolve</code> and <code>reject</code> functions associated with it.</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16325"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Let <var>obj</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_16326"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<emu-xref href="#sec-properties-of-the-object-prototype-object" id="_ref_16327"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16328"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"promise"</emu-val>, <var>promiseCapability</var>.<var class="field">[[Promise]]</var>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16329"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"resolve"</emu-val>, <var>promiseCapability</var>.<var class="field">[[Resolve]]</var>).</li><li>Perform !&nbsp;<emu-xref aoid="CreateDataPropertyOrThrow" id="_ref_16330"><a href="abstract-operations.html#sec-createdatapropertyorthrow">CreateDataPropertyOrThrow</a></emu-xref>(<var>obj</var>, <emu-val>"reject"</emu-val>, <var>promiseCapability</var>.<var class="field">[[Reject]]</var>).</li><li>Return <var>obj</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause oldids="sec-get-promise-@@species" id="sec-get-promise-%symbol.species%" type="built-in function"><span id="sec-get-promise-@@species"></span>
<h1><span class="secnum">27.2.4.10</span> get Promise [ %Symbol.species% ]</h1>
<p><code>Promise[%Symbol.species%]</code> is an <emu-xref href="#sec-object-type" id="_ref_16331"><a href="ecmascript-data-types-and-values.html#sec-object-type">accessor property</a></emu-xref> whose set accessor function is <emu-val>undefined</emu-val>. Its get accessor function performs the following steps when called:</p>
<emu-alg><ol><li>Return the <emu-val>this</emu-val> value.</li></ol></emu-alg>
<p>The value of the <emu-val>"name"</emu-val> property of this function is <emu-val>"get [Symbol.species]"</emu-val>.</p>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Promise prototype methods normally use their <emu-val>this</emu-val> value's <emu-xref href="#constructor" id="_ref_16332"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to create a derived object. However, a subclass <emu-xref href="#constructor" id="_ref_16333"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> may over-ride that default behaviour by redefining its <emu-xref href="#sec-well-known-symbols" id="_ref_16334"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.species%</a></emu-xref> property.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-the-promise-prototype-object">
<h1><span class="secnum">27.2.5</span> Properties of the Promise Prototype Object</h1>
<p>The <dfn tabindex="-1">Promise prototype object</dfn>:</p>
<ul>
<li>is <dfn tabindex="-1">%Promise.prototype%</dfn>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-object-prototype-object" id="_ref_16335"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_16336"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>does not have a <var class="field">[[PromiseState]]</var> internal slot or any of the other internal slots of Promise instances.</li>
</ul>
<emu-clause id="sec-promise.prototype.catch" type="built-in function">
<h1><span class="secnum">27.2.5.1</span> Promise.prototype.catch ( <var>onRejected</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>promise</var> be the <emu-val>this</emu-val> value.</li><li>Return ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16337"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>promise</var>, <emu-val>"then"</emu-val>, « <emu-val>undefined</emu-val>, <var>onRejected</var>&nbsp;»).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-promise.prototype.constructor">
<h1><span class="secnum">27.2.5.2</span> Promise.prototype.constructor</h1>
<p>The initial value of <code>Promise.prototype.constructor</code> is <emu-xref href="#sec-promise-constructor" id="_ref_16338"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>.</p>
</emu-clause>
<emu-clause id="sec-promise.prototype.finally" oldids="sec-thenfinallyfunctions,sec-catchfinallyfunctions" type="built-in function"><span id="sec-catchfinallyfunctions"></span><span id="sec-thenfinallyfunctions"></span>
<h1><span class="secnum">27.2.5.3</span> Promise.prototype.finally ( <var>onFinally</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>promise</var> be the <emu-val>this</emu-val> value.</li><li>If <var>promise</var> <emu-xref href="#sec-object-type" id="_ref_16339"><a href="ecmascript-data-types-and-values.html#sec-object-type">is not an Object</a></emu-xref>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>C</var> be ?&nbsp;<emu-xref aoid="SpeciesConstructor" id="_ref_16340"><a href="abstract-operations.html#sec-speciesconstructor" class="e-user-code">SpeciesConstructor</a></emu-xref>(<var>promise</var>, <emu-xref href="#sec-promise-constructor" id="_ref_16341"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li><emu-xref href="#assert" id="_ref_16342"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <emu-xref aoid="IsConstructor" id="_ref_16343"><a href="abstract-operations.html#sec-isconstructor">IsConstructor</a></emu-xref>(<var>C</var>) is <emu-val>true</emu-val>.</li><li>If <emu-xref aoid="IsCallable" id="_ref_16344"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>onFinally</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>thenFinally</var> be <var>onFinally</var>.</li><li>Let <var>catchFinally</var> be <var>onFinally</var>.</li></ol></li><li>Else,<ol><li>Let <var>thenFinallyClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16345"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>value</var>) that captures <var>onFinally</var> and <var>C</var> and performs the following steps when called:<ol><li>Let <var>result</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_16346"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>onFinally</var>, <emu-val>undefined</emu-val>).</li><li>Let <var>p</var> be ?&nbsp;<emu-xref aoid="PromiseResolve" id="_ref_16347"><a href="control-abstraction-objects.html#sec-promise-resolve" class="e-user-code">PromiseResolve</a></emu-xref>(<var>C</var>, <var>result</var>).</li><li>Let <var>returnValue</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16348"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>value</var> and performs the following steps when called:<ol><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16349"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>value</var>).</li></ol></li><li>Let <var>valueThunk</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16350"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>returnValue</var>, 0, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Return ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16351"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>p</var>, <emu-val>"then"</emu-val>, « <var>valueThunk</var>&nbsp;»).</li></ol></li><li>Let <var>thenFinally</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16352"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>thenFinallyClosure</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Let <var>catchFinallyClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16353"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>reason</var>) that captures <var>onFinally</var> and <var>C</var> and performs the following steps when called:<ol><li>Let <var>result</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_16354"><a href="abstract-operations.html#sec-call" class="e-user-code">Call</a></emu-xref>(<var>onFinally</var>, <emu-val>undefined</emu-val>).</li><li>Let <var>p</var> be ?&nbsp;<emu-xref aoid="PromiseResolve" id="_ref_16355"><a href="control-abstraction-objects.html#sec-promise-resolve" class="e-user-code">PromiseResolve</a></emu-xref>(<var>C</var>, <var>result</var>).</li><li>Let <var>throwReason</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16356"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>reason</var> and performs the following steps when called:<ol><li>Return <emu-xref aoid="ThrowCompletion" id="_ref_16357"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>reason</var>).</li></ol></li><li>Let <var>thrower</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16358"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>throwReason</var>, 0, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Return ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16359"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>p</var>, <emu-val>"then"</emu-val>, « <var>thrower</var>&nbsp;»).</li></ol></li><li>Let <var>catchFinally</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16360"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>catchFinallyClosure</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li></ol></li><li>Return ?&nbsp;<emu-xref aoid="Invoke" id="_ref_16361"><a href="abstract-operations.html#sec-invoke" class="e-user-code">Invoke</a></emu-xref>(<var>promise</var>, <emu-val>"then"</emu-val>, « <var>thenFinally</var>, <var>catchFinally</var>&nbsp;»).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-promise.prototype.then" type="built-in function">
<h1><span class="secnum">27.2.5.4</span> Promise.prototype.then ( <var>onFulfilled</var>, <var>onRejected</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>promise</var> be the <emu-val>this</emu-val> value.</li><li>If <emu-xref aoid="IsPromise" id="_ref_16362"><a href="control-abstraction-objects.html#sec-ispromise">IsPromise</a></emu-xref>(<var>promise</var>) is <emu-val>false</emu-val>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Let <var>C</var> be ?&nbsp;<emu-xref aoid="SpeciesConstructor" id="_ref_16363"><a href="abstract-operations.html#sec-speciesconstructor" class="e-user-code">SpeciesConstructor</a></emu-xref>(<var>promise</var>, <emu-xref href="#sec-promise-constructor" id="_ref_16364"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>resultCapability</var> be ?&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16365"><a href="control-abstraction-objects.html#sec-newpromisecapability" class="e-user-code">NewPromiseCapability</a></emu-xref>(<var>C</var>).</li><li>Return <emu-xref aoid="PerformPromiseThen" id="_ref_16366"><a href="control-abstraction-objects.html#sec-performpromisethen">PerformPromiseThen</a></emu-xref>(<var>promise</var>, <var>onFulfilled</var>, <var>onRejected</var>, <var>resultCapability</var>).</li></ol></emu-alg>
<emu-clause id="sec-performpromisethen" type="abstract operation" aoid="PerformPromiseThen">
<h1><span class="secnum">27.2.5.4.1</span> PerformPromiseThen ( <var>promise</var>, <var>onFulfilled</var>, <var>onRejected</var> [ , <var>resultCapability</var> ] )</h1>
<p>The abstract operation PerformPromiseThen takes arguments <var>promise</var> (a Promise), <var>onFulfilled</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16367"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>), and <var>onRejected</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16368"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and optional argument <var>resultCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16369"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>) and returns an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16370"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>. It performs the “then” operation on <var>promise</var> using <var>onFulfilled</var> and <var>onRejected</var> as its settlement actions. If <var>resultCapability</var> is passed, the result is stored by updating <var>resultCapability</var>'s promise. If it is not passed, then PerformPromiseThen is being called by a specification-internal operation where the result does not matter. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16371"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <emu-xref aoid="IsPromise" id="_ref_16372"><a href="control-abstraction-objects.html#sec-ispromise">IsPromise</a></emu-xref>(<var>promise</var>) is <emu-val>true</emu-val>.</li><li>If <var>resultCapability</var> is not present, then<ol><li>Set <var>resultCapability</var> to <emu-val>undefined</emu-val>.</li></ol></li><li>If <emu-xref aoid="IsCallable" id="_ref_16373"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>onFulfilled</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>onFulfilledJobCallback</var> be <emu-const>empty</emu-const>.</li></ol></li><li>Else,<ol><li>Let <var>onFulfilledJobCallback</var> be <emu-xref aoid="HostMakeJobCallback" id="_ref_16374"><a href="executable-code-and-execution-contexts.html#sec-hostmakejobcallback">HostMakeJobCallback</a></emu-xref>(<var>onFulfilled</var>).</li></ol></li><li>If <emu-xref aoid="IsCallable" id="_ref_16375"><a href="abstract-operations.html#sec-iscallable">IsCallable</a></emu-xref>(<var>onRejected</var>) is <emu-val>false</emu-val>, then<ol><li>Let <var>onRejectedJobCallback</var> be <emu-const>empty</emu-const>.</li></ol></li><li>Else,<ol><li>Let <var>onRejectedJobCallback</var> be <emu-xref aoid="HostMakeJobCallback" id="_ref_16376"><a href="executable-code-and-execution-contexts.html#sec-hostmakejobcallback">HostMakeJobCallback</a></emu-xref>(<var>onRejected</var>).</li></ol></li><li>Let <var>fulfillReaction</var> be the <emu-xref href="#sec-promisereaction-records" id="_ref_16377"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Record</a></emu-xref> { <var class="field">[[Capability]]</var>: <var>resultCapability</var>, <var class="field">[[Type]]</var>: <emu-const>fulfill</emu-const>, <var class="field">[[Handler]]</var>: <var>onFulfilledJobCallback</var>&nbsp;}.</li><li>Let <var>rejectReaction</var> be the <emu-xref href="#sec-promisereaction-records" id="_ref_16378"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Record</a></emu-xref> { <var class="field">[[Capability]]</var>: <var>resultCapability</var>, <var class="field">[[Type]]</var>: <emu-const>reject</emu-const>, <var class="field">[[Handler]]</var>: <var>onRejectedJobCallback</var>&nbsp;}.</li><li>If <var>promise</var>.<var class="field">[[PromiseState]]</var> is <emu-const>pending</emu-const>, then<ol><li>Append <var>fulfillReaction</var> to <var>promise</var>.<var class="field">[[PromiseFulfillReactions]]</var>.</li><li>Append <var>rejectReaction</var> to <var>promise</var>.<var class="field">[[PromiseRejectReactions]]</var>.</li></ol></li><li>Else if <var>promise</var>.<var class="field">[[PromiseState]]</var> is <emu-const>fulfilled</emu-const>, then<ol><li>Let <var>value</var> be <var>promise</var>.<var class="field">[[PromiseResult]]</var>.</li><li>Let <var>fulfillJob</var> be <emu-xref aoid="NewPromiseReactionJob" id="_ref_16379"><a href="control-abstraction-objects.html#sec-newpromisereactionjob">NewPromiseReactionJob</a></emu-xref>(<var>fulfillReaction</var>, <var>value</var>).</li><li>Perform <emu-xref aoid="HostEnqueuePromiseJob" id="_ref_16380"><a href="executable-code-and-execution-contexts.html#sec-hostenqueuepromisejob">HostEnqueuePromiseJob</a></emu-xref>(<var>fulfillJob</var>.<var class="field">[[Job]]</var>, <var>fulfillJob</var>.<var class="field">[[Realm]]</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16381"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>promise</var>.<var class="field">[[PromiseState]]</var> is <emu-const>rejected</emu-const>.</li><li>Let <var>reason</var> be <var>promise</var>.<var class="field">[[PromiseResult]]</var>.</li><li>If <var>promise</var>.<var class="field">[[PromiseIsHandled]]</var> is <emu-val>false</emu-val>, perform <emu-xref aoid="HostPromiseRejectionTracker" id="_ref_16382"><a href="control-abstraction-objects.html#sec-host-promise-rejection-tracker">HostPromiseRejectionTracker</a></emu-xref>(<var>promise</var>, <emu-val>"handle"</emu-val>).</li><li>Let <var>rejectJob</var> be <emu-xref aoid="NewPromiseReactionJob" id="_ref_16383"><a href="control-abstraction-objects.html#sec-newpromisereactionjob">NewPromiseReactionJob</a></emu-xref>(<var>rejectReaction</var>, <var>reason</var>).</li><li>Perform <emu-xref aoid="HostEnqueuePromiseJob" id="_ref_16384"><a href="executable-code-and-execution-contexts.html#sec-hostenqueuepromisejob">HostEnqueuePromiseJob</a></emu-xref>(<var>rejectJob</var>.<var class="field">[[Job]]</var>, <var>rejectJob</var>.<var class="field">[[Realm]]</var>).</li></ol></li><li>Set <var>promise</var>.<var class="field">[[PromiseIsHandled]]</var> to <emu-val>true</emu-val>.</li><li>If <var>resultCapability</var> is <emu-val>undefined</emu-val>, return <emu-val>undefined</emu-val>.</li><li>Return <var>resultCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause oldids="sec-promise.prototype-@@tostringtag" id="sec-promise.prototype-%symbol.tostringtag%"><span id="sec-promise.prototype-@@tostringtag"></span>
<h1><span class="secnum">27.2.5.5</span> Promise.prototype [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_16385"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"Promise"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-promise-instances">
<h1><span class="secnum">27.2.6</span> Properties of Promise Instances</h1>
<p>Promise instances are <emu-xref href="#ordinary-object" id="_ref_16386"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary objects</a></emu-xref> that inherit properties from the <emu-xref href="#sec-properties-of-the-promise-prototype-object" id="_ref_16387"><a href="control-abstraction-objects.html#sec-properties-of-the-promise-prototype-object">Promise prototype object</a></emu-xref> (the intrinsic, <emu-xref href="#sec-properties-of-the-promise-prototype-object" id="_ref_16388"><a href="control-abstraction-objects.html#sec-properties-of-the-promise-prototype-object">%Promise.prototype%</a></emu-xref>). Promise instances are initially created with the internal slots described in <emu-xref href="#table-internal-slots-of-promise-instances" id="_ref_828"><a href="control-abstraction-objects.html#table-internal-slots-of-promise-instances">Table 87</a></emu-xref>.</p>
<emu-table id="table-internal-slots-of-promise-instances" caption="Internal Slots of Promise Instances" oldids="table-59"><figure><figcaption>Table 87: Internal Slots of Promise Instances</figcaption><span id="table-59"></span>
<table>
<thead>
<tr>
<th>
Internal Slot
</th>
<th>
Type
</th>
<th>
Description
</th>
</tr>
</thead>
<tbody><tr>
<td>
<var class="field">[[PromiseState]]</var>
</td>
<td>
<emu-const>pending</emu-const>, <emu-const>fulfilled</emu-const>, or <emu-const>rejected</emu-const>
</td>
<td>
Governs how a promise will react to incoming calls to its <code>then</code> method.
</td>
</tr>
<tr>
<td>
<var class="field">[[PromiseResult]]</var>
</td>
<td>
an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16389"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or <emu-const>empty</emu-const>
</td>
<td>
The value with which the promise has been fulfilled or rejected, if any. <emu-const>empty</emu-const> if and only if the <var class="field">[[PromiseState]]</var> is <emu-const>pending</emu-const>.
</td>
</tr>
<tr>
<td>
<var class="field">[[PromiseFulfillReactions]]</var>
</td>
<td>
a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16390"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-xref href="#sec-promisereaction-records" id="_ref_16391"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Records</a></emu-xref>
</td>
<td>
<emu-xref href="#sec-list-and-record-specification-type" id="_ref_16392"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Records</a></emu-xref> to be processed when/if the promise transitions from the <emu-const>pending</emu-const> state to the <emu-const>fulfilled</emu-const> state.
</td>
</tr>
<tr>
<td>
<var class="field">[[PromiseRejectReactions]]</var>
</td>
<td>
a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16393"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-xref href="#sec-promisereaction-records" id="_ref_16394"><a href="control-abstraction-objects.html#sec-promisereaction-records">PromiseReaction Records</a></emu-xref>
</td>
<td>
<emu-xref href="#sec-list-and-record-specification-type" id="_ref_16395"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Records</a></emu-xref> to be processed when/if the promise transitions from the <emu-const>pending</emu-const> state to the <emu-const>rejected</emu-const> state.
</td>
</tr>
<tr>
<td>
<var class="field">[[PromiseIsHandled]]</var>
</td>
<td>
a Boolean
</td>
<td>
Indicates whether the promise has ever had a fulfillment or rejection handler; used in unhandled rejection tracking.
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
</emu-clause>
<emu-clause id="sec-generatorfunction-objects">
<h1><span class="secnum">27.3</span> GeneratorFunction Objects</h1>
<p>GeneratorFunctions are functions that are usually created by evaluating <emu-nt id="_ref_24555"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorDeclaration">GeneratorDeclaration</a></emu-nt>s, <emu-nt id="_ref_24556"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorExpression">GeneratorExpression</a></emu-nt>s, and <emu-nt id="_ref_24557"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorMethod">GeneratorMethod</a></emu-nt>s. They may also be created by calling the <emu-xref href="#sec-generatorfunction-constructor" id="_ref_16396"><a href="control-abstraction-objects.html#sec-generatorfunction-constructor">%GeneratorFunction%</a></emu-xref> intrinsic.</p>
<emu-figure id="figure-2" caption="Generator Objects Relationships" informative=""><figure><figcaption>Figure 6 (Informative): Generator Objects Relationships</figcaption>
<img alt="A staggering variety of boxes and arrows." height="700" src="../img/figure-2.svg" width="900">
</figure></emu-figure>
<emu-clause id="sec-generatorfunction-constructor">
<h1><span class="secnum">27.3.1</span> The GeneratorFunction Constructor</h1>
<p>The GeneratorFunction <emu-xref href="#constructor" id="_ref_16397"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is <dfn tabindex="-1">%GeneratorFunction%</dfn>.</li>
<li>is a subclass of <code>Function</code>.</li>
<li>creates and initializes a new GeneratorFunction when called as a function rather than as a <emu-xref href="#constructor" id="_ref_16398"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>. Thus the function call <code>GeneratorFunction (…)</code> is equivalent to the object creation expression <code>new GeneratorFunction (…)</code> with the same arguments.</li>
<li>may be used as the value of an <code>extends</code> clause of a class definition. Subclass <emu-xref href="#constructor" id="_ref_16399"><a href="ecmascript-data-types-and-values.html#constructor">constructors</a></emu-xref> that intend to inherit the specified GeneratorFunction behaviour must include a <code>super</code> call to the GeneratorFunction <emu-xref href="#constructor" id="_ref_16400"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to create and initialize subclass instances with the internal slots necessary for built-in GeneratorFunction behaviour. All ECMAScript syntactic forms for defining generator <emu-xref href="#function-object" id="_ref_16401"><a href="ecmascript-data-types-and-values.html#function-object">function objects</a></emu-xref> create direct instances of GeneratorFunction. There is no syntactic means to create instances of GeneratorFunction subclasses.</li>
</ul>
<emu-clause id="sec-generatorfunction" type="built-in function">
<h1><span class="secnum">27.3.1.1</span> GeneratorFunction ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</h1>
<p>The last argument (if any) specifies the body (executable code) of a generator function; any preceding arguments specify formal parameters.</p>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-xref href="#active-function-object" id="_ref_16402"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>bodyArg</var> is not present, set <var>bodyArg</var> to the empty String.</li><li>Return ?&nbsp;<emu-xref aoid="CreateDynamicFunction" id="_ref_16403"><a href="fundamental-objects.html#sec-createdynamicfunction" class="e-user-code">CreateDynamicFunction</a></emu-xref>(<var>C</var>, NewTarget, <emu-const>generator</emu-const>, <var>parameterArgs</var>, <var>bodyArg</var>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>See NOTE for <emu-xref href="#sec-function-p1-p2-pn-body" id="_ref_829"><a href="fundamental-objects.html#sec-function-p1-p2-pn-body">20.2.1.1</a></emu-xref>.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-the-generatorfunction-constructor">
<h1><span class="secnum">27.3.2</span> Properties of the GeneratorFunction Constructor</h1>
<p>The GeneratorFunction <emu-xref href="#constructor" id="_ref_16404"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is a standard built-in <emu-xref href="#function-object" id="_ref_16405"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> that inherits from the Function <emu-xref href="#constructor" id="_ref_16406"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-function-constructor" id="_ref_16407"><a href="fundamental-objects.html#sec-function-constructor">%Function%</a></emu-xref>.</li>
<li oldids="sec-generatorfunction.length"><span id="sec-generatorfunction.length"></span>has a <emu-val>"length"</emu-val> property whose value is <emu-val>1</emu-val><sub>𝔽</sub>.</li>
<li>has a <emu-val>"name"</emu-val> property whose value is <emu-val>"GeneratorFunction"</emu-val>.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-generatorfunction.prototype">
<h1><span class="secnum">27.3.2.1</span> GeneratorFunction.prototype</h1>
<p>The initial value of <code>GeneratorFunction.prototype</code> is the <emu-xref href="#sec-properties-of-the-generatorfunction-prototype-object" id="_ref_16408"><a href="control-abstraction-objects.html#sec-properties-of-the-generatorfunction-prototype-object">GeneratorFunction prototype object</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-the-generatorfunction-prototype-object">
<h1><span class="secnum">27.3.3</span> Properties of the GeneratorFunction Prototype Object</h1>
<p>The <dfn tabindex="-1">GeneratorFunction prototype object</dfn>:</p>
<ul>
<li>is <dfn tabindex="-1">%GeneratorFunction.prototype%</dfn> (see <emu-xref href="#figure-2" id="_ref_830"><a href="control-abstraction-objects.html#figure-2">Figure 6</a></emu-xref>).</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_16409"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>is not a <emu-xref href="#function-object" id="_ref_16410"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> and does not have an <var class="field">[[ECMAScriptCode]]</var> internal slot or any other of the internal slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects" id="_ref_831"><a href="ordinary-and-exotic-objects-behaviours.html#table-internal-slots-of-ecmascript-function-objects">Table 25</a></emu-xref> or <emu-xref href="#table-internal-slots-of-generator-instances" id="_ref_832"><a href="control-abstraction-objects.html#table-internal-slots-of-generator-instances">Table 88</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-function-prototype-object" id="_ref_16411"><a href="fundamental-objects.html#sec-properties-of-the-function-prototype-object">%Function.prototype%</a></emu-xref>.</li>
</ul>
<emu-clause id="sec-generatorfunction.prototype.constructor">
<h1><span class="secnum">27.3.3.1</span> GeneratorFunction.prototype.constructor</h1>
<p>The initial value of <code>GeneratorFunction.prototype.constructor</code> is <emu-xref href="#sec-generatorfunction-constructor" id="_ref_16412"><a href="control-abstraction-objects.html#sec-generatorfunction-constructor">%GeneratorFunction%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause id="sec-generatorfunction.prototype.prototype">
<h1><span class="secnum">27.3.3.2</span> GeneratorFunction.prototype.prototype</h1>
<p>The initial value of <code>GeneratorFunction.prototype.prototype</code> is <emu-xref href="#sec-properties-of-generator-prototype" id="_ref_16413"><a href="control-abstraction-objects.html#sec-properties-of-generator-prototype">%GeneratorPrototype%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause oldids="sec-generatorfunction.prototype-@@tostringtag" id="sec-generatorfunction.prototype-%symbol.tostringtag%"><span id="sec-generatorfunction.prototype-@@tostringtag"></span>
<h1><span class="secnum">27.3.3.3</span> GeneratorFunction.prototype [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_16414"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"GeneratorFunction"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-generatorfunction-instances">
<h1><span class="secnum">27.3.4</span> GeneratorFunction Instances</h1>
<p>Every GeneratorFunction instance is an ECMAScript <emu-xref href="#function-object" id="_ref_16415"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> and has the internal slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects" id="_ref_833"><a href="ordinary-and-exotic-objects-behaviours.html#table-internal-slots-of-ecmascript-function-objects">Table 25</a></emu-xref>. The value of the <var class="field">[[IsClassConstructor]]</var> internal slot for all such instances is <emu-val>false</emu-val>.</p>
<p>Each GeneratorFunction instance has the following own properties:</p>
<emu-clause id="sec-generatorfunction-instances-length">
<h1><span class="secnum">27.3.4.1</span> length</h1>
<p>The specification for the <emu-val>"length"</emu-val> property of Function instances given in <emu-xref href="#sec-function-instances-length" id="_ref_834"><a href="fundamental-objects.html#sec-function-instances-length">20.2.4.1</a></emu-xref> also applies to GeneratorFunction instances.</p>
</emu-clause>
<emu-clause id="sec-generatorfunction-instances-name">
<h1><span class="secnum">27.3.4.2</span> name</h1>
<p>The specification for the <emu-val>"name"</emu-val> property of Function instances given in <emu-xref href="#sec-function-instances-name" id="_ref_835"><a href="fundamental-objects.html#sec-function-instances-name">20.2.4.2</a></emu-xref> also applies to GeneratorFunction instances.</p>
</emu-clause>
<emu-clause id="sec-generatorfunction-instances-prototype">
<h1><span class="secnum">27.3.4.3</span> prototype</h1>
<p>Whenever a GeneratorFunction instance is created another <emu-xref href="#ordinary-object" id="_ref_16416"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref> is also created and is the initial value of the generator function's <emu-val>"prototype"</emu-val> property. The value of the prototype property is used to initialize the <var class="field">[[Prototype]]</var> internal slot of a newly created Generator when the generator <emu-xref href="#function-object" id="_ref_16417"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> is invoked using <var class="field">[[Call]]</var>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>true</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Unlike Function instances, the object that is the value of a GeneratorFunction's <emu-val>"prototype"</emu-val> property does not have a <emu-val>"constructor"</emu-val> property whose value is the GeneratorFunction instance.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-asyncgeneratorfunction-objects">
<h1><span class="secnum">27.4</span> AsyncGeneratorFunction Objects</h1>
<p>AsyncGeneratorFunctions are functions that are usually created by evaluating <emu-nt id="_ref_24558"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorDeclaration">AsyncGeneratorDeclaration</a></emu-nt>, <emu-nt id="_ref_24559"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorExpression">AsyncGeneratorExpression</a></emu-nt>, and <emu-nt id="_ref_24560"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorMethod">AsyncGeneratorMethod</a></emu-nt> syntactic productions. They may also be created by calling the <emu-xref href="#sec-asyncgeneratorfunction-constructor" id="_ref_16418"><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-constructor">%AsyncGeneratorFunction%</a></emu-xref> intrinsic.</p>
<emu-clause id="sec-asyncgeneratorfunction-constructor">
<h1><span class="secnum">27.4.1</span> The AsyncGeneratorFunction Constructor</h1>
<p>The AsyncGeneratorFunction <emu-xref href="#constructor" id="_ref_16419"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is <dfn tabindex="-1">%AsyncGeneratorFunction%</dfn>.</li>
<li>is a subclass of <code>Function</code>.</li>
<li>creates and initializes a new AsyncGeneratorFunction when called as a function rather than as a <emu-xref href="#constructor" id="_ref_16420"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>. Thus the function call <code>AsyncGeneratorFunction (...)</code> is equivalent to the object creation expression <code>new AsyncGeneratorFunction (...)</code> with the same arguments.</li>
<li>may be used as the value of an <code>extends</code> clause of a class definition. Subclass <emu-xref href="#constructor" id="_ref_16421"><a href="ecmascript-data-types-and-values.html#constructor">constructors</a></emu-xref> that intend to inherit the specified AsyncGeneratorFunction behaviour must include a <code>super</code> call to the AsyncGeneratorFunction <emu-xref href="#constructor" id="_ref_16422"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to create and initialize subclass instances with the internal slots necessary for built-in AsyncGeneratorFunction behaviour. All ECMAScript syntactic forms for defining async generator <emu-xref href="#function-object" id="_ref_16423"><a href="ecmascript-data-types-and-values.html#function-object">function objects</a></emu-xref> create direct instances of AsyncGeneratorFunction. There is no syntactic means to create instances of AsyncGeneratorFunction subclasses.</li>
</ul>
<emu-clause id="sec-asyncgeneratorfunction" type="built-in function">
<h1><span class="secnum">27.4.1.1</span> AsyncGeneratorFunction ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</h1>
<p>The last argument (if any) specifies the body (executable code) of an async generator function; any preceding arguments specify formal parameters.</p>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-xref href="#active-function-object" id="_ref_16424"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>bodyArg</var> is not present, set <var>bodyArg</var> to the empty String.</li><li>Return ?&nbsp;<emu-xref aoid="CreateDynamicFunction" id="_ref_16425"><a href="fundamental-objects.html#sec-createdynamicfunction" class="e-user-code">CreateDynamicFunction</a></emu-xref>(<var>C</var>, NewTarget, <emu-const>async-generator</emu-const>, <var>parameterArgs</var>, <var>bodyArg</var>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>See NOTE for <emu-xref href="#sec-function-p1-p2-pn-body" id="_ref_836"><a href="fundamental-objects.html#sec-function-p1-p2-pn-body">20.2.1.1</a></emu-xref>.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-asyncgeneratorfunction">
<h1><span class="secnum">27.4.2</span> Properties of the AsyncGeneratorFunction Constructor</h1>
<p>The AsyncGeneratorFunction <emu-xref href="#constructor" id="_ref_16426"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is a standard built-in <emu-xref href="#function-object" id="_ref_16427"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> that inherits from the Function <emu-xref href="#constructor" id="_ref_16428"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-function-constructor" id="_ref_16429"><a href="fundamental-objects.html#sec-function-constructor">%Function%</a></emu-xref>.</li>
<li oldids="sec-asyncgeneratorfunction-length"><span id="sec-asyncgeneratorfunction-length"></span>has a <emu-val>"length"</emu-val> property whose value is <emu-val>1</emu-val><sub>𝔽</sub>.</li>
<li>has a <emu-val>"name"</emu-val> property whose value is <emu-val>"AsyncGeneratorFunction"</emu-val>.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-asyncgeneratorfunction-prototype">
<h1><span class="secnum">27.4.2.1</span> AsyncGeneratorFunction.prototype</h1>
<p>The initial value of <code>AsyncGeneratorFunction.prototype</code> is the <emu-xref href="#sec-properties-of-asyncgeneratorfunction-prototype" id="_ref_16430"><a href="control-abstraction-objects.html#sec-properties-of-asyncgeneratorfunction-prototype">AsyncGeneratorFunction prototype object</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-asyncgeneratorfunction-prototype">
<h1><span class="secnum">27.4.3</span> Properties of the AsyncGeneratorFunction Prototype Object</h1>
<p>The <dfn tabindex="-1">AsyncGeneratorFunction prototype object</dfn>:</p>
<ul>
<li>is <dfn tabindex="-1">%AsyncGeneratorFunction.prototype%</dfn>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_16431"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>is not a <emu-xref href="#function-object" id="_ref_16432"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> and does not have an <var class="field">[[ECMAScriptCode]]</var> internal slot or any other of the internal slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects" id="_ref_837"><a href="ordinary-and-exotic-objects-behaviours.html#table-internal-slots-of-ecmascript-function-objects">Table 25</a></emu-xref> or <emu-xref href="#table-internal-slots-of-asyncgenerator-instances" id="_ref_838"><a href="control-abstraction-objects.html#table-internal-slots-of-asyncgenerator-instances">Table 89</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-function-prototype-object" id="_ref_16433"><a href="fundamental-objects.html#sec-properties-of-the-function-prototype-object">%Function.prototype%</a></emu-xref>.</li>
</ul>
<emu-clause id="sec-asyncgeneratorfunction-prototype-constructor">
<h1><span class="secnum">27.4.3.1</span> AsyncGeneratorFunction.prototype.constructor</h1>
<p>The initial value of <code>AsyncGeneratorFunction.prototype.constructor</code> is <emu-xref href="#sec-asyncgeneratorfunction-constructor" id="_ref_16434"><a href="control-abstraction-objects.html#sec-asyncgeneratorfunction-constructor">%AsyncGeneratorFunction%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause id="sec-asyncgeneratorfunction-prototype-prototype">
<h1><span class="secnum">27.4.3.2</span> AsyncGeneratorFunction.prototype.prototype</h1>
<p>The initial value of <code>AsyncGeneratorFunction.prototype.prototype</code> is <emu-xref href="#sec-properties-of-asyncgenerator-prototype" id="_ref_16435"><a href="control-abstraction-objects.html#sec-properties-of-asyncgenerator-prototype">%AsyncGeneratorPrototype%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause oldids="sec-asyncgeneratorfunction-prototype-tostringtag" id="sec-asyncgeneratorfunction-prototype-%symbol.tostringtag%"><span id="sec-asyncgeneratorfunction-prototype-tostringtag"></span>
<h1><span class="secnum">27.4.3.3</span> AsyncGeneratorFunction.prototype [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_16436"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"AsyncGeneratorFunction"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-asyncgeneratorfunction-instances">
<h1><span class="secnum">27.4.4</span> AsyncGeneratorFunction Instances</h1>
<p>Every AsyncGeneratorFunction instance is an ECMAScript <emu-xref href="#function-object" id="_ref_16437"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> and has the internal slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects" id="_ref_839"><a href="ordinary-and-exotic-objects-behaviours.html#table-internal-slots-of-ecmascript-function-objects">Table 25</a></emu-xref>. The value of the <var class="field">[[IsClassConstructor]]</var> internal slot for all such instances is <emu-val>false</emu-val>.</p>
<p>Each AsyncGeneratorFunction instance has the following own properties:</p>
<emu-clause id="sec-asyncgeneratorfunction-instance-length">
<h1><span class="secnum">27.4.4.1</span> length</h1>
<p>The value of the <emu-val>"length"</emu-val> property is an <emu-xref href="#integral-number" id="_ref_16438"><a href="notational-conventions.html#integral-number">integral Number</a></emu-xref> that indicates the typical number of arguments expected by the AsyncGeneratorFunction. However, the language permits the function to be invoked with some other number of arguments. The behaviour of an AsyncGeneratorFunction when invoked on a number of arguments other than the number specified by its <emu-val>"length"</emu-val> property depends on the function.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause id="sec-asyncgeneratorfunction-instance-name">
<h1><span class="secnum">27.4.4.2</span> name</h1>
<p>The specification for the <emu-val>"name"</emu-val> property of Function instances given in <emu-xref href="#sec-function-instances-name" id="_ref_840"><a href="fundamental-objects.html#sec-function-instances-name">20.2.4.2</a></emu-xref> also applies to AsyncGeneratorFunction instances.</p>
</emu-clause>
<emu-clause id="sec-asyncgeneratorfunction-instance-prototype">
<h1><span class="secnum">27.4.4.3</span> prototype</h1>
<p>Whenever an AsyncGeneratorFunction instance is created, another <emu-xref href="#ordinary-object" id="_ref_16439"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref> is also created and is the initial value of the async generator function's <emu-val>"prototype"</emu-val> property. The value of the prototype property is used to initialize the <var class="field">[[Prototype]]</var> internal slot of a newly created AsyncGenerator when the generator <emu-xref href="#function-object" id="_ref_16440"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> is invoked using <var class="field">[[Call]]</var>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>true</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Unlike function instances, the object that is the value of an AsyncGeneratorFunction's <emu-val>"prototype"</emu-val> property does not have a <emu-val>"constructor"</emu-val> property whose value is the AsyncGeneratorFunction instance.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-generator-objects">
<h1><span class="secnum">27.5</span> Generator Objects</h1>
<p>A Generator is created by calling a generator function and conforms to both the <emu-xref href="#sec-iterator-interface" id="_ref_16441"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator interface</a></emu-xref> and the <emu-xref href="#sec-iterable-interface" id="_ref_16442"><a href="control-abstraction-objects.html#sec-iterable-interface">iterable interface</a></emu-xref>.</p>
<p>Generator instances directly inherit properties from the initial value of the <emu-val>"prototype"</emu-val> property of the generator function that created the instance. Generator instances indirectly inherit properties from <emu-xref href="#sec-properties-of-generator-prototype" id="_ref_16443"><a href="control-abstraction-objects.html#sec-properties-of-generator-prototype">%GeneratorPrototype%</a></emu-xref>.</p>
<emu-clause id="sec-properties-of-generator-prototype">
<h1><span class="secnum">27.5.1</span> The %GeneratorPrototype% Object</h1>
<p>The <dfn tabindex="-1">%GeneratorPrototype%</dfn> object:</p>
<ul>
<li>is <dfn tabindex="-1">%GeneratorFunction.prototype.prototype%</dfn>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_16444"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>is not a Generator instance and does not have a <var class="field">[[GeneratorState]]</var> internal slot.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-%iterator.prototype%-object" id="_ref_16445"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">%Iterator.prototype%</a></emu-xref>.</li>
<li>has properties that are indirectly inherited by all Generator instances.</li>
</ul>
<emu-clause id="sec-generator.prototype.constructor">
<h1><span class="secnum">27.5.1.1</span> %GeneratorPrototype%.constructor</h1>
<p>The initial value of <emu-xref href="#sec-properties-of-generator-prototype" id="_ref_16446"><a href="control-abstraction-objects.html#sec-properties-of-generator-prototype">%GeneratorPrototype%</a></emu-xref><code>.constructor</code> is <emu-xref href="#sec-properties-of-the-generatorfunction-prototype-object" id="_ref_16447"><a href="control-abstraction-objects.html#sec-properties-of-the-generatorfunction-prototype-object">%GeneratorFunction.prototype%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause id="sec-generator.prototype.next" type="built-in function">
<h1><span class="secnum">27.5.1.2</span> %GeneratorPrototype%.next ( <var>value</var> )</h1>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="GeneratorResume" id="_ref_16448"><a href="control-abstraction-objects.html#sec-generatorresume" class="e-user-code">GeneratorResume</a></emu-xref>(<emu-val>this</emu-val> value, <var>value</var>, <emu-const>empty</emu-const>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-generator.prototype.return" type="built-in function">
<h1><span class="secnum">27.5.1.3</span> %GeneratorPrototype%.return ( <var>value</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>g</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>C</var> be <emu-xref aoid="ReturnCompletion" id="_ref_16449"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<var>value</var>).</li><li>Return ?&nbsp;<emu-xref aoid="GeneratorResumeAbrupt" id="_ref_16450"><a href="control-abstraction-objects.html#sec-generatorresumeabrupt" class="e-user-code">GeneratorResumeAbrupt</a></emu-xref>(<var>g</var>, <var>C</var>, <emu-const>empty</emu-const>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-generator.prototype.throw" type="built-in function">
<h1><span class="secnum">27.5.1.4</span> %GeneratorPrototype%.throw ( <var>exception</var> )</h1>
<p>This method performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>g</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>C</var> be <emu-xref aoid="ThrowCompletion" id="_ref_16451"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>exception</var>).</li><li>Return ?&nbsp;<emu-xref aoid="GeneratorResumeAbrupt" id="_ref_16452"><a href="control-abstraction-objects.html#sec-generatorresumeabrupt" class="e-user-code">GeneratorResumeAbrupt</a></emu-xref>(<var>g</var>, <var>C</var>, <emu-const>empty</emu-const>).</li></ol></emu-alg>
</emu-clause>
<emu-clause oldids="sec-generator.prototype-@@tostringtag" id="sec-generator.prototype-%symbol.tostringtag%"><span id="sec-generator.prototype-@@tostringtag"></span>
<h1><span class="secnum">27.5.1.5</span> %GeneratorPrototype% [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_16453"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"Generator"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-generator-instances">
<h1><span class="secnum">27.5.2</span> Properties of Generator Instances</h1>
<p>Generator instances are initially created with the internal slots described in <emu-xref href="#table-internal-slots-of-generator-instances" id="_ref_841"><a href="control-abstraction-objects.html#table-internal-slots-of-generator-instances">Table 88</a></emu-xref>.</p>
<emu-table id="table-internal-slots-of-generator-instances" caption="Internal Slots of Generator Instances" oldids="table-56"><figure><figcaption>Table 88: Internal Slots of Generator Instances</figcaption><span id="table-56"></span>
<table>
<thead>
<tr>
<th>
Internal Slot
</th>
<th>
Type
</th>
<th>
Description
</th>
</tr>
</thead>
<tbody><tr>
<td>
<var class="field">[[GeneratorState]]</var>
</td>
<td>
<emu-const>suspended-start</emu-const>, <emu-const>suspended-yield</emu-const>, <emu-const>executing</emu-const>, or <emu-const>completed</emu-const>
</td>
<td>
The current execution state of the generator.
</td>
</tr>
<tr>
<td>
<var class="field">[[GeneratorContext]]</var>
</td>
<td>
an <emu-xref href="#sec-execution-contexts" id="_ref_16454"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref>
</td>
<td>
The <emu-xref href="#sec-execution-contexts" id="_ref_16455"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is used when executing the code of this generator.
</td>
</tr>
<tr>
<td>
<var class="field">[[GeneratorBrand]]</var>
</td>
<td>
a String or <emu-const>empty</emu-const>
</td>
<td>
A brand used to distinguish different kinds of generators. The <var class="field">[[GeneratorBrand]]</var> of generators declared by <emu-xref href="#sec-source-text" id="_ref_16456"><a href="ecmascript-language-source-code.html#sec-source-text">ECMAScript source text</a></emu-xref> is always <emu-const>empty</emu-const>.
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-generator-abstract-operations">
<h1><span class="secnum">27.5.3</span> Generator Abstract Operations</h1>
<emu-clause id="sec-generatorstart" type="abstract operation" aoid="GeneratorStart">
<h1><span class="secnum">27.5.3.1</span> GeneratorStart ( <var>generator</var>, <var>generatorBody</var> )</h1>
<p>The abstract operation GeneratorStart takes arguments <var>generator</var> (a Generator) and <var>generatorBody</var> (a <emu-nt id="_ref_24561"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionBody">FunctionBody</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_16457"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> or an <emu-xref href="#sec-abstract-closure" id="_ref_16458"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16459"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[GeneratorState]]</var> is <emu-const>suspended-start</emu-const>.</li><li>Let <var>genContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16460"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Set the Generator component of <var>genContext</var> to <var>generator</var>.</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16461"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>generatorBody</var> and performs the following steps when called:<ol><li>Let <var>acGenContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16462"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>acGenerator</var> be the Generator component of <var>acGenContext</var>.</li><li>If <var>generatorBody</var> is a <emu-xref href="#sec-syntactic-grammar" id="_ref_16463"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>, then<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16464"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_16465"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>generatorBody</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16466"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generatorBody</var> is an <emu-xref href="#sec-abstract-closure" id="_ref_16467"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16468"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<var>generatorBody</var>()).</li></ol></li><li><emu-xref href="#assert" id="_ref_16469"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: If we return here, the generator either threw an exception or performed either an implicit or explicit return.</li><li>Remove <var>acGenContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16470"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore the <emu-xref href="#sec-execution-contexts" id="_ref_16471"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is at the top of the <emu-xref href="#execution-context-stack" id="_ref_16472"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> as the <emu-xref href="#running-execution-context" id="_ref_16473"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Set <var>acGenerator</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>completed</emu-const>.</li><li>NOTE: Once a generator enters the <emu-const>completed</emu-const> state it never leaves it and its associated <emu-xref href="#sec-execution-contexts" id="_ref_16474"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> is never resumed. Any execution state associated with <var>acGenerator</var> can be discarded at this point.</li><li>If <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16475"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, then<ol><li>Let <var>resultValue</var> be <emu-val>undefined</emu-val>.</li></ol></li><li>Else if <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16476"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>, then<ol><li>Let <var>resultValue</var> be <var>result</var>.<var class="field">[[Value]]</var>.</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16477"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16478"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>.</li><li>Return ?&nbsp;<var>result</var>.</li></ol></li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16479"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-xref aoid="CreateIteratorResultObject" id="_ref_16480"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>resultValue</var>, <emu-val>true</emu-val>)).</li></ol></li><li>Set the code evaluation state of <var>genContext</var> such that when evaluation is resumed for that <emu-xref href="#sec-execution-contexts" id="_ref_16481"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref>, <var>closure</var> will be called with no arguments.</li><li>Set <var>generator</var>.<var class="field">[[GeneratorContext]]</var> to <var>genContext</var>.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-generatorvalidate" type="abstract operation" aoid="GeneratorValidate">
<h1><span class="secnum">27.5.3.2</span> GeneratorValidate ( <var>generator</var>, <var>generatorBrand</var> )</h1>
<p>The abstract operation GeneratorValidate takes arguments <var>generator</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16482"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and <var>generatorBrand</var> (a String or <emu-const>empty</emu-const>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16483"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> one of <emu-const>suspended-start</emu-const>, <emu-const>suspended-yield</emu-const>, or <emu-const>completed</emu-const>, or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16484"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_16485"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>generator</var>, <var class="field">[[GeneratorState]]</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_16486"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>generator</var>, <var class="field">[[GeneratorBrand]]</var>).</li><li>If <var>generator</var>.<var class="field">[[GeneratorBrand]]</var> is not <var>generatorBrand</var>, throw a <emu-val>TypeError</emu-val> exception.</li><li><emu-xref href="#assert" id="_ref_16487"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var> has a <var class="field">[[GeneratorContext]]</var> internal slot.</li><li>Let <var>state</var> be <var>generator</var>.<var class="field">[[GeneratorState]]</var>.</li><li>If <var>state</var> is <emu-const>executing</emu-const>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Return <var>state</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-generatorresume" type="abstract operation" aoid="GeneratorResume">
<h1><span class="secnum">27.5.3.3</span> GeneratorResume ( <var>generator</var>, <var>value</var>, <var>generatorBrand</var> )</h1>
<p>The abstract operation GeneratorResume takes arguments <var>generator</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16488"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>), <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16489"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or <emu-const>empty</emu-const>), and <var>generatorBrand</var> (a String or <emu-const>empty</emu-const>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16490"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16491"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16492"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>state</var> be ?&nbsp;<emu-xref aoid="GeneratorValidate" id="_ref_16493"><a href="control-abstraction-objects.html#sec-generatorvalidate">GeneratorValidate</a></emu-xref>(<var>generator</var>, <var>generatorBrand</var>).</li><li>If <var>state</var> is <emu-const>completed</emu-const>, return <emu-xref aoid="CreateIteratorResultObject" id="_ref_16494"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<emu-val>undefined</emu-val>, <emu-val>true</emu-val>).</li><li><emu-xref href="#assert" id="_ref_16495"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>state</var> is either <emu-const>suspended-start</emu-const> or <emu-const>suspended-yield</emu-const>.</li><li>Let <var>genContext</var> be <var>generator</var>.<var class="field">[[GeneratorContext]]</var>.</li><li>Let <var>methodContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16496"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Suspend <var>methodContext</var>.</li><li>Set <var>generator</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>executing</emu-const>.</li><li>Push <var>genContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16497"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>genContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16498"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><span class="e-user-code">Resume the suspended evaluation of <var>genContext</var></span> using <emu-xref aoid="NormalCompletion" id="_ref_16499"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>value</var>) as the result of the operation that suspended it. Let <var>result</var> be the value returned by the resumed computation.</li><li><emu-xref href="#assert" id="_ref_16500"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: When we return here, <var>genContext</var> has already been removed from the <emu-xref href="#execution-context-stack" id="_ref_16501"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and <var>methodContext</var> is the currently <emu-xref href="#running-execution-context" id="_ref_16502"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Return ?&nbsp;<var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-generatorresumeabrupt" type="abstract operation" aoid="GeneratorResumeAbrupt">
<h1><span class="secnum">27.5.3.4</span> GeneratorResumeAbrupt ( <var>generator</var>, <var>abruptCompletion</var>, <var>generatorBrand</var> )</h1>
<p>The abstract operation GeneratorResumeAbrupt takes arguments <var>generator</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16503"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>), <var>abruptCompletion</var> (a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16504"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16505"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>), and <var>generatorBrand</var> (a String or <emu-const>empty</emu-const>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16506"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16507"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16508"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>state</var> be ?&nbsp;<emu-xref aoid="GeneratorValidate" id="_ref_16509"><a href="control-abstraction-objects.html#sec-generatorvalidate">GeneratorValidate</a></emu-xref>(<var>generator</var>, <var>generatorBrand</var>).</li><li>If <var>state</var> is <emu-const>suspended-start</emu-const>, then<ol><li>Set <var>generator</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>completed</emu-const>.</li><li>NOTE: Once a generator enters the <emu-const>completed</emu-const> state it never leaves it and its associated <emu-xref href="#sec-execution-contexts" id="_ref_16510"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> is never resumed. Any execution state associated with <var>generator</var> can be discarded at this point.</li><li>Set <var>state</var> to <emu-const>completed</emu-const>.</li></ol></li><li>If <var>state</var> is <emu-const>completed</emu-const>, then<ol><li>If <var>abruptCompletion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16511"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>, then<ol><li>Return <emu-xref aoid="CreateIteratorResultObject" id="_ref_16512"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>abruptCompletion</var>.<var class="field">[[Value]]</var>, <emu-val>true</emu-val>).</li></ol></li><li>Return ?&nbsp;<var>abruptCompletion</var>.</li></ol></li><li><emu-xref href="#assert" id="_ref_16513"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>state</var> is <emu-const>suspended-yield</emu-const>.</li><li>Let <var>genContext</var> be <var>generator</var>.<var class="field">[[GeneratorContext]]</var>.</li><li>Let <var>methodContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16514"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Suspend <var>methodContext</var>.</li><li>Set <var>generator</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>executing</emu-const>.</li><li>Push <var>genContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16515"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>genContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16516"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><span class="e-user-code">Resume the suspended evaluation of <var>genContext</var></span> using <var>abruptCompletion</var> as the result of the operation that suspended it. Let <var>result</var> be the <emu-xref href="#sec-completion-record-specification-type" id="_ref_16517"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> returned by the resumed computation.</li><li><emu-xref href="#assert" id="_ref_16518"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: When we return here, <var>genContext</var> has already been removed from the <emu-xref href="#execution-context-stack" id="_ref_16519"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and <var>methodContext</var> is the currently <emu-xref href="#running-execution-context" id="_ref_16520"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Return ?&nbsp;<var>result</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-getgeneratorkind" type="abstract operation" aoid="GetGeneratorKind">
<h1><span class="secnum">27.5.3.5</span> GetGeneratorKind ( )</h1>
<p>The abstract operation GetGeneratorKind takes no arguments and returns <emu-const>non-generator</emu-const>, <emu-const>sync</emu-const>, or <emu-const>async</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>genContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16521"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>If <var>genContext</var> does not have a Generator component, return <emu-const>non-generator</emu-const>.</li><li>Let <var>generator</var> be the Generator component of <var>genContext</var>.</li><li>If <var>generator</var> has an <var class="field">[[AsyncGeneratorState]]</var> internal slot, return <emu-const>async</emu-const>.</li><li>Return <emu-const>sync</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-generatoryield" type="abstract operation" aoid="GeneratorYield">
<h1><span class="secnum">27.5.3.6</span> GeneratorYield ( <var>iteratorResult</var> )</h1>
<p>The abstract operation GeneratorYield takes argument <var>iteratorResult</var> (an Object that conforms to the <emu-xref href="#sec-iteratorresult-interface" id="_ref_16522"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult interface</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16523"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16524"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16525"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>genContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16526"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><emu-xref href="#assert" id="_ref_16527"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>genContext</var> is the <emu-xref href="#sec-execution-contexts" id="_ref_16528"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> of a generator.</li><li>Let <var>generator</var> be the value of the Generator component of <var>genContext</var>.</li><li><emu-xref href="#assert" id="_ref_16529"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <emu-xref aoid="GetGeneratorKind" id="_ref_16530"><a href="control-abstraction-objects.html#sec-getgeneratorkind">GetGeneratorKind</a></emu-xref>() is <emu-const>sync</emu-const>.</li><li>Set <var>generator</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>suspended-yield</emu-const>.</li><li>Remove <var>genContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16531"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore the <emu-xref href="#sec-execution-contexts" id="_ref_16532"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is at the top of the <emu-xref href="#execution-context-stack" id="_ref_16533"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> as the <emu-xref href="#running-execution-context" id="_ref_16534"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>callerContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16535"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Resume <var>callerContext</var> passing <emu-xref aoid="NormalCompletion" id="_ref_16536"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>iteratorResult</var>). If <var>genContext</var> is ever resumed again, let <var>resumptionValue</var> be the <emu-xref href="#sec-completion-record-specification-type" id="_ref_16537"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> with which it is resumed.</li><li><emu-xref href="#assert" id="_ref_16538"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: If control reaches here, then <var>genContext</var> is the <emu-xref href="#running-execution-context" id="_ref_16539"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref> again.</li><li>Return <var>resumptionValue</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-yield" type="abstract operation" aoid="Yield">
<h1><span class="secnum">27.5.3.7</span> Yield ( <var>value</var> )</h1>
<p>The abstract operation Yield takes argument <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16540"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16541"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16542"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16543"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>generatorKind</var> be <emu-xref aoid="GetGeneratorKind" id="_ref_16544"><a href="control-abstraction-objects.html#sec-getgeneratorkind">GetGeneratorKind</a></emu-xref>().</li><li>If <var>generatorKind</var> is <emu-const>async</emu-const>, return ?&nbsp;<emu-xref aoid="AsyncGeneratorYield" id="_ref_16545"><a href="control-abstraction-objects.html#sec-asyncgeneratoryield" class="e-user-code">AsyncGeneratorYield</a></emu-xref>(? <emu-xref aoid="Await" id="_ref_16546"><a href="control-abstraction-objects.html#await" class="e-user-code">Await</a></emu-xref>(<var>value</var>)).</li><li>Return ?&nbsp;<emu-xref aoid="GeneratorYield" id="_ref_16547"><a href="control-abstraction-objects.html#sec-generatoryield">GeneratorYield</a></emu-xref>(<emu-xref aoid="CreateIteratorResultObject" id="_ref_16548"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>value</var>, <emu-val>false</emu-val>)).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-createiteratorfromclosure" type="abstract operation" aoid="CreateIteratorFromClosure">
<h1><span class="secnum">27.5.3.8</span> CreateIteratorFromClosure ( <var>closure</var>, <var>generatorBrand</var>, <var>generatorPrototype</var> [ , <var>extraSlots</var> ] )</h1>
<p>The abstract operation CreateIteratorFromClosure takes arguments <var>closure</var> (an <emu-xref href="#sec-abstract-closure" id="_ref_16549"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters), <var>generatorBrand</var> (a String or <emu-const>empty</emu-const>), and <var>generatorPrototype</var> (an Object) and optional argument <var>extraSlots</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16550"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of names of internal slots) and returns a Generator. It performs the following steps when called:</p>
<emu-alg><ol><li>NOTE: <var>closure</var> can contain uses of the <emu-xref aoid="Yield" id="_ref_16551"><a href="control-abstraction-objects.html#sec-yield">Yield</a></emu-xref> operation to yield an <emu-xref href="#sec-iteratorresult-interface" id="_ref_16552"><a href="control-abstraction-objects.html#sec-iteratorresult-interface">IteratorResult object</a></emu-xref>.</li><li>If <var>extraSlots</var> is not present, set <var>extraSlots</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16553"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Let <var>internalSlotsList</var> be the <emu-xref href="#list-concatenation" id="_ref_16554"><a href="ecmascript-data-types-and-values.html#list-concatenation">list-concatenation</a></emu-xref> of <var>extraSlots</var> and « <var class="field">[[GeneratorState]]</var>, <var class="field">[[GeneratorContext]]</var>, <var class="field">[[GeneratorBrand]]</var>&nbsp;».</li><li>Let <var>generator</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_16555"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<var>generatorPrototype</var>, <var>internalSlotsList</var>).</li><li>Set <var>generator</var>.<var class="field">[[GeneratorBrand]]</var> to <var>generatorBrand</var>.</li><li>Set <var>generator</var>.<var class="field">[[GeneratorState]]</var> to <emu-const>suspended-start</emu-const>.</li><li>Let <var>callerContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16556"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>calleeContext</var> be a new <emu-xref href="#sec-execution-contexts" id="_ref_16557"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref>.</li><li>Set the Function of <var>calleeContext</var> to <emu-val>null</emu-val>.</li><li>Set the <emu-xref href="#realm" id="_ref_16558"><a href="executable-code-and-execution-contexts.html#realm">Realm</a></emu-xref> of <var>calleeContext</var> to <emu-xref href="#current-realm" id="_ref_16559"><a href="executable-code-and-execution-contexts.html#current-realm">the current Realm Record</a></emu-xref>.</li><li>Set the ScriptOrModule of <var>calleeContext</var> to <var>callerContext</var>'s ScriptOrModule.</li><li>If <var>callerContext</var> is not already suspended, suspend <var>callerContext</var>.</li><li>Push <var>calleeContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16560"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>calleeContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16561"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Perform <emu-xref aoid="GeneratorStart" id="_ref_16562"><a href="control-abstraction-objects.html#sec-generatorstart">GeneratorStart</a></emu-xref>(<var>generator</var>, <var>closure</var>).</li><li>Remove <var>calleeContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16563"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore <var>callerContext</var> as the <emu-xref href="#running-execution-context" id="_ref_16564"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Return <var>generator</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-asyncgenerator-objects">
<h1><span class="secnum">27.6</span> AsyncGenerator Objects</h1>
<p>An AsyncGenerator is created by calling an async generator function and conforms to both the <emu-xref href="#sec-asynciterator-interface" id="_ref_16565"><a href="control-abstraction-objects.html#sec-asynciterator-interface">async iterator interface</a></emu-xref> and the <emu-xref href="#sec-asynciterable-interface" id="_ref_16566"><a href="control-abstraction-objects.html#sec-asynciterable-interface">async iterable interface</a></emu-xref>.</p>
<p>AsyncGenerator instances directly inherit properties from the initial value of the <emu-val>"prototype"</emu-val> property of the async generator function that created the instance. AsyncGenerator instances indirectly inherit properties from <emu-xref href="#sec-properties-of-asyncgenerator-prototype" id="_ref_16567"><a href="control-abstraction-objects.html#sec-properties-of-asyncgenerator-prototype">%AsyncGeneratorPrototype%</a></emu-xref>.</p>
<emu-clause id="sec-properties-of-asyncgenerator-prototype">
<h1><span class="secnum">27.6.1</span> The %AsyncGeneratorPrototype% Object</h1>
<p>The <dfn tabindex="-1">%AsyncGeneratorPrototype%</dfn> object:</p>
<ul>
<li>is <dfn tabindex="-1">%AsyncGeneratorFunction.prototype.prototype%</dfn>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_16568"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>is not an AsyncGenerator instance and does not have an <var class="field">[[AsyncGeneratorState]]</var> internal slot.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-asynciteratorprototype" id="_ref_16569"><a href="control-abstraction-objects.html#sec-asynciteratorprototype">%AsyncIteratorPrototype%</a></emu-xref>.</li>
<li>has properties that are indirectly inherited by all AsyncGenerator instances.</li>
</ul>
<emu-clause id="sec-asyncgenerator-prototype-constructor">
<h1><span class="secnum">27.6.1.1</span> %AsyncGeneratorPrototype%.constructor</h1>
<p>The initial value of <emu-xref href="#sec-properties-of-asyncgenerator-prototype" id="_ref_16570"><a href="control-abstraction-objects.html#sec-properties-of-asyncgenerator-prototype">%AsyncGeneratorPrototype%</a></emu-xref><code>.constructor</code> is <emu-xref href="#sec-properties-of-asyncgeneratorfunction-prototype" id="_ref_16571"><a href="control-abstraction-objects.html#sec-properties-of-asyncgeneratorfunction-prototype">%AsyncGeneratorFunction.prototype%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause id="sec-asyncgenerator-prototype-next" type="built-in function">
<h1><span class="secnum">27.6.1.2</span> %AsyncGeneratorPrototype%.next ( <var>value</var> )</h1>
<emu-alg><ol><li>Let <var>generator</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be !&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16572"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_16573"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16574"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="AsyncGeneratorValidate" id="_ref_16575"><a href="control-abstraction-objects.html#sec-asyncgeneratorvalidate">AsyncGeneratorValidate</a></emu-xref>(<var>generator</var>, <emu-const>empty</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16576"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>Let <var>state</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var>.</li><li>If <var>state</var> is <emu-const>completed</emu-const>, then<ol><li>Let <var>iteratorResult</var> be <emu-xref aoid="CreateIteratorResultObject" id="_ref_16577"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<emu-val>undefined</emu-val>, <emu-val>true</emu-val>).</li><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16578"><a href="abstract-operations.html#sec-call" class="e-user-code e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>iteratorResult</var>&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Let <var>completion</var> be <emu-xref aoid="NormalCompletion" id="_ref_16579"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>value</var>).</li><li>Perform <emu-xref aoid="AsyncGeneratorEnqueue" id="_ref_16580"><a href="control-abstraction-objects.html#sec-asyncgeneratorenqueue">AsyncGeneratorEnqueue</a></emu-xref>(<var>generator</var>, <var>completion</var>, <var>promiseCapability</var>).</li><li>If <var>state</var> is either <emu-const>suspended-start</emu-const> or <emu-const>suspended-yield</emu-const>, then<ol><li>Perform <emu-xref aoid="AsyncGeneratorResume" id="_ref_16581"><a href="control-abstraction-objects.html#sec-asyncgeneratorresume" class="e-user-code">AsyncGeneratorResume</a></emu-xref>(<var>generator</var>, <var>completion</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16582"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>state</var> is either <emu-const>executing</emu-const> or <emu-const>draining-queue</emu-const>.</li></ol></li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgenerator-prototype-return" type="built-in function">
<h1><span class="secnum">27.6.1.3</span> %AsyncGeneratorPrototype%.return ( <var>value</var> )</h1>
<emu-alg><ol><li>Let <var>generator</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be !&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16583"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_16584"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16585"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="AsyncGeneratorValidate" id="_ref_16586"><a href="control-abstraction-objects.html#sec-asyncgeneratorvalidate">AsyncGeneratorValidate</a></emu-xref>(<var>generator</var>, <emu-const>empty</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16587"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>Let <var>completion</var> be <emu-xref aoid="ReturnCompletion" id="_ref_16588"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<var>value</var>).</li><li>Perform <emu-xref aoid="AsyncGeneratorEnqueue" id="_ref_16589"><a href="control-abstraction-objects.html#sec-asyncgeneratorenqueue">AsyncGeneratorEnqueue</a></emu-xref>(<var>generator</var>, <var>completion</var>, <var>promiseCapability</var>).</li><li>Let <var>state</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var>.</li><li>If <var>state</var> is either <emu-const>suspended-start</emu-const> or <emu-const>completed</emu-const>, then<ol><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> to <emu-const>draining-queue</emu-const>.</li><li>Perform <emu-xref aoid="AsyncGeneratorAwaitReturn" id="_ref_16590"><a href="control-abstraction-objects.html#sec-asyncgeneratorawaitreturn" class="e-user-code">AsyncGeneratorAwaitReturn</a></emu-xref>(<var>generator</var>).</li></ol></li><li>Else if <var>state</var> is <emu-const>suspended-yield</emu-const>, then<ol><li>Perform <emu-xref aoid="AsyncGeneratorResume" id="_ref_16591"><a href="control-abstraction-objects.html#sec-asyncgeneratorresume" class="e-user-code">AsyncGeneratorResume</a></emu-xref>(<var>generator</var>, <var>completion</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16592"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>state</var> is either <emu-const>executing</emu-const> or <emu-const>draining-queue</emu-const>.</li></ol></li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgenerator-prototype-throw" type="built-in function">
<h1><span class="secnum">27.6.1.4</span> %AsyncGeneratorPrototype%.throw ( <var>exception</var> )</h1>
<emu-alg><ol><li>Let <var>generator</var> be the <emu-val>this</emu-val> value.</li><li>Let <var>promiseCapability</var> be !&nbsp;<emu-xref aoid="NewPromiseCapability" id="_ref_16593"><a href="control-abstraction-objects.html#sec-newpromisecapability">NewPromiseCapability</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_16594"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>).</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16595"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="AsyncGeneratorValidate" id="_ref_16596"><a href="control-abstraction-objects.html#sec-asyncgeneratorvalidate">AsyncGeneratorValidate</a></emu-xref>(<var>generator</var>, <emu-const>empty</emu-const>)).</li><li><emu-xref aoid="IfAbruptRejectPromise" id="_ref_16597"><a href="control-abstraction-objects.html#sec-ifabruptrejectpromise" class="e-user-code">IfAbruptRejectPromise</a></emu-xref>(<var>result</var>, <var>promiseCapability</var>).</li><li>Let <var>state</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var>.</li><li>If <var>state</var> is <emu-const>suspended-start</emu-const>, then<ol><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> to <emu-const>completed</emu-const>.</li><li>Set <var>state</var> to <emu-const>completed</emu-const>.</li></ol></li><li>If <var>state</var> is <emu-const>completed</emu-const>, then<ol><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16598"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>exception</var>&nbsp;»).</li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></li><li>Let <var>completion</var> be <emu-xref aoid="ThrowCompletion" id="_ref_16599"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>exception</var>).</li><li>Perform <emu-xref aoid="AsyncGeneratorEnqueue" id="_ref_16600"><a href="control-abstraction-objects.html#sec-asyncgeneratorenqueue">AsyncGeneratorEnqueue</a></emu-xref>(<var>generator</var>, <var>completion</var>, <var>promiseCapability</var>).</li><li>If <var>state</var> is <emu-const>suspended-yield</emu-const>, then<ol><li>Perform <emu-xref aoid="AsyncGeneratorResume" id="_ref_16601"><a href="control-abstraction-objects.html#sec-asyncgeneratorresume" class="e-user-code">AsyncGeneratorResume</a></emu-xref>(<var>generator</var>, <var>completion</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16602"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>state</var> is either <emu-const>executing</emu-const> or <emu-const>draining-queue</emu-const>.</li></ol></li><li>Return <var>promiseCapability</var>.<var class="field">[[Promise]]</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause oldids="sec-asyncgenerator-prototype-tostringtag" id="sec-asyncgenerator-prototype-%symbol.tostringtag%"><span id="sec-asyncgenerator-prototype-tostringtag"></span>
<h1><span class="secnum">27.6.1.5</span> %AsyncGeneratorPrototype% [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_16603"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"AsyncGenerator"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-asyncgenerator-intances">
<h1><span class="secnum">27.6.2</span> Properties of AsyncGenerator Instances</h1>
<p>AsyncGenerator instances are initially created with the internal slots described below:</p>
<emu-table id="table-internal-slots-of-asyncgenerator-instances" caption="Internal Slots of AsyncGenerator Instances"><figure><figcaption>Table 89: Internal Slots of AsyncGenerator Instances</figcaption>
<table>
<thead>
<tr>
<th>Internal Slot</th>
<th>Type</th>
<th>Description</th>
</tr>
</thead>
<tbody><tr>
<td><var class="field">[[AsyncGeneratorState]]</var></td>
<td><emu-const>suspended-start</emu-const>, <emu-const>suspended-yield</emu-const>, <emu-const>executing</emu-const>, <emu-const>draining-queue</emu-const>, or <emu-const>completed</emu-const></td>
<td>The current execution state of the async generator.</td>
</tr>
<tr>
<td><var class="field">[[AsyncGeneratorContext]]</var></td>
<td>an <emu-xref href="#sec-execution-contexts" id="_ref_16604"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref></td>
<td>The <emu-xref href="#sec-execution-contexts" id="_ref_16605"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is used when executing the code of this async generator.</td>
</tr>
<tr>
<td><var class="field">[[AsyncGeneratorQueue]]</var></td>
<td>a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16606"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-xref href="#sec-asyncgeneratorrequest-records" id="_ref_16607"><a href="control-abstraction-objects.html#sec-asyncgeneratorrequest-records">AsyncGeneratorRequest</a></emu-xref> <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16608"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Records</a></emu-xref></td>
<td><emu-xref href="#sec-list-and-record-specification-type" id="_ref_16609"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Records</a></emu-xref> which represent requests to resume the async generator. Except during state transitions, it is non-empty if and only if <var class="field">[[AsyncGeneratorState]]</var> is either <emu-const>executing</emu-const> or <emu-const>draining-queue</emu-const>.</td>
</tr>
<tr>
<td><var class="field">[[GeneratorBrand]]</var></td>
<td>a String or <emu-const>empty</emu-const></td>
<td>A brand used to distinguish different kinds of async generators. The <var class="field">[[GeneratorBrand]]</var> of async generators declared by <emu-xref href="#sec-source-text" id="_ref_16610"><a href="ecmascript-language-source-code.html#sec-source-text">ECMAScript source text</a></emu-xref> is always <emu-const>empty</emu-const>.</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-asyncgenerator-abstract-operations">
<h1><span class="secnum">27.6.3</span> AsyncGenerator Abstract Operations</h1>
<emu-clause id="sec-asyncgeneratorrequest-records">
<h1><span class="secnum">27.6.3.1</span> AsyncGeneratorRequest Records</h1>
<p>An <dfn variants="AsyncGeneratorRequests" tabindex="-1">AsyncGeneratorRequest</dfn> is a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16611"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> value used to store information about how an async generator should be resumed and contains capabilities for fulfilling or rejecting the corresponding promise.</p>
<p>They have the following fields:</p>
<emu-table caption="AsyncGeneratorRequest Record Fields"><figure><figcaption>Table 90: AsyncGeneratorRequest <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16612"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">Record</a></emu-xref> Fields</figcaption>
<table>
<thead>
<tr>
<th>Field Name</th>
<th>Value</th>
<th>Meaning</th>
</tr>
</thead>
<tbody><tr>
<td><var class="field">[[Completion]]</var></td>
<td>a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16613"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref></td>
<td>The <emu-xref href="#sec-completion-record-specification-type" id="_ref_16614"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> which should be used to resume the async generator.</td>
</tr>
<tr>
<td><var class="field">[[Capability]]</var></td>
<td>a <emu-xref href="#sec-promisecapability-records" id="_ref_16615"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref></td>
<td>The promise capabilities associated with this request.</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
<emu-clause id="sec-asyncgeneratorstart" type="abstract operation" aoid="AsyncGeneratorStart">
<h1><span class="secnum">27.6.3.2</span> AsyncGeneratorStart ( <var>generator</var>, <var>generatorBody</var> )</h1>
<p>The abstract operation AsyncGeneratorStart takes arguments <var>generator</var> (an AsyncGenerator) and <var>generatorBody</var> (a <emu-nt id="_ref_24562"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionBody">FunctionBody</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_16616"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> or an <emu-xref href="#sec-abstract-closure" id="_ref_16617"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16618"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> is <emu-const>suspended-start</emu-const>.</li><li>Let <var>genContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16619"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Set the Generator component of <var>genContext</var> to <var>generator</var>.</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16620"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>generatorBody</var> and performs the following steps when called:<ol><li>Let <var>acGenContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16621"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>acGenerator</var> be the Generator component of <var>acGenContext</var>.</li><li>If <var>generatorBody</var> is a <emu-xref href="#sec-syntactic-grammar" id="_ref_16622"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>, then<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16623"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_16624"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>generatorBody</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16625"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generatorBody</var> is an <emu-xref href="#sec-abstract-closure" id="_ref_16626"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16627"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<var>generatorBody</var>()).</li></ol></li><li><emu-xref href="#assert" id="_ref_16628"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: If we return here, the async generator either threw an exception or performed either an implicit or explicit return.</li><li>Remove <var>acGenContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16629"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore the <emu-xref href="#sec-execution-contexts" id="_ref_16630"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is at the top of the <emu-xref href="#execution-context-stack" id="_ref_16631"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> as the <emu-xref href="#running-execution-context" id="_ref_16632"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Set <var>acGenerator</var>.<var class="field">[[AsyncGeneratorState]]</var> to <emu-const>draining-queue</emu-const>.</li><li>If <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16633"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, set <var>result</var> to <emu-xref aoid="NormalCompletion" id="_ref_16634"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>If <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16635"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>, set <var>result</var> to <emu-xref aoid="NormalCompletion" id="_ref_16636"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>result</var>.<var class="field">[[Value]]</var>).</li><li>Perform <emu-xref aoid="AsyncGeneratorCompleteStep" id="_ref_16637"><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" class="e-user-code">AsyncGeneratorCompleteStep</a></emu-xref>(<var>acGenerator</var>, <var>result</var>, <emu-val>true</emu-val>).</li><li>Perform <emu-xref aoid="AsyncGeneratorDrainQueue" id="_ref_16638"><a href="control-abstraction-objects.html#sec-asyncgeneratordrainqueue" class="e-user-code">AsyncGeneratorDrainQueue</a></emu-xref>(<var>acGenerator</var>).</li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16639"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Set the code evaluation state of <var>genContext</var> such that when evaluation is resumed for that <emu-xref href="#sec-execution-contexts" id="_ref_16640"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref>, <var>closure</var> will be called with no arguments.</li><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorContext]]</var> to <var>genContext</var>.</li><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_16641"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratorvalidate" type="abstract operation" aoid="AsyncGeneratorValidate">
<h1><span class="secnum">27.6.3.3</span> AsyncGeneratorValidate ( <var>generator</var>, <var>generatorBrand</var> )</h1>
<p>The abstract operation AsyncGeneratorValidate takes arguments <var>generator</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16642"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and <var>generatorBrand</var> (a String or <emu-const>empty</emu-const>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16643"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> <emu-const>unused</emu-const> or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16644"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_16645"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>generator</var>, <var class="field">[[AsyncGeneratorContext]]</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_16646"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>generator</var>, <var class="field">[[AsyncGeneratorState]]</var>).</li><li>Perform ?&nbsp;<emu-xref aoid="RequireInternalSlot" id="_ref_16647"><a href="ordinary-and-exotic-objects-behaviours.html#sec-requireinternalslot">RequireInternalSlot</a></emu-xref>(<var>generator</var>, <var class="field">[[AsyncGeneratorQueue]]</var>).</li><li>If <var>generator</var>.<var class="field">[[GeneratorBrand]]</var> is not <var>generatorBrand</var>, throw a <emu-val>TypeError</emu-val> exception.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratorenqueue" type="abstract operation" aoid="AsyncGeneratorEnqueue">
<h1><span class="secnum">27.6.3.4</span> AsyncGeneratorEnqueue ( <var>generator</var>, <var>completion</var>, <var>promiseCapability</var> )</h1>
<p>The abstract operation AsyncGeneratorEnqueue takes arguments <var>generator</var> (an AsyncGenerator), <var>completion</var> (a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16648"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>), and <var>promiseCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16649"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>request</var> be <emu-xref href="#sec-asyncgeneratorrequest-records" id="_ref_16650"><a href="control-abstraction-objects.html#sec-asyncgeneratorrequest-records">AsyncGeneratorRequest</a></emu-xref> { <var class="field">[[Completion]]</var>: <var>completion</var>, <var class="field">[[Capability]]</var>: <var>promiseCapability</var>&nbsp;}.</li><li>Append <var>request</var> to <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var>.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratorcompletestep" type="abstract operation" aoid="AsyncGeneratorCompleteStep">
<h1><span class="secnum">27.6.3.5</span> AsyncGeneratorCompleteStep ( <var>generator</var>, <var>completion</var>, <var>done</var> [ , <var>realm</var> ] )</h1>
<p>The abstract operation AsyncGeneratorCompleteStep takes arguments <var>generator</var> (an AsyncGenerator), <var>completion</var> (a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16651"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>), and <var>done</var> (a Boolean) and optional argument <var>realm</var> (a <emu-xref href="#realm-record" id="_ref_16652"><a href="executable-code-and-execution-contexts.html#realm-record">Realm Record</a></emu-xref>) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16653"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var> is not empty.</li><li>Let <var>next</var> be the first element of <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var>.</li><li>Remove the first element from <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var>.</li><li>Let <var>promiseCapability</var> be <var>next</var>.<var class="field">[[Capability]]</var>.</li><li>Let <var>value</var> be <var>completion</var>.<var class="field">[[Value]]</var>.</li><li>If <var>completion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16654"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>, then<ol><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16655"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>value</var>&nbsp;»).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16656"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>completion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16657"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>.</li><li>If <var>realm</var> is present, then<ol><li>Let <var>oldRealm</var> be the <emu-xref href="#running-execution-context" id="_ref_16658"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s <emu-xref href="#realm" id="_ref_16659"><a href="executable-code-and-execution-contexts.html#realm">Realm</a></emu-xref>.</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_16660"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s <emu-xref href="#realm" id="_ref_16661"><a href="executable-code-and-execution-contexts.html#realm">Realm</a></emu-xref> to <var>realm</var>.</li><li>Let <var>iteratorResult</var> be <emu-xref aoid="CreateIteratorResultObject" id="_ref_16662"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>value</var>, <var>done</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_16663"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s <emu-xref href="#realm" id="_ref_16664"><a href="executable-code-and-execution-contexts.html#realm">Realm</a></emu-xref> to <var>oldRealm</var>.</li></ol></li><li>Else,<ol><li>Let <var>iteratorResult</var> be <emu-xref aoid="CreateIteratorResultObject" id="_ref_16665"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>value</var>, <var>done</var>).</li></ol></li><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16666"><a href="abstract-operations.html#sec-call" class="e-user-code e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>iteratorResult</var>&nbsp;»).</li></ol></li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratorresume" type="abstract operation" aoid="AsyncGeneratorResume">
<h1><span class="secnum">27.6.3.6</span> AsyncGeneratorResume ( <var>generator</var>, <var>completion</var> )</h1>
<p>The abstract operation AsyncGeneratorResume takes arguments <var>generator</var> (an AsyncGenerator) and <var>completion</var> (a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16667"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16668"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> is either <emu-const>suspended-start</emu-const> or <emu-const>suspended-yield</emu-const>.</li><li>Let <var>genContext</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorContext]]</var>.</li><li>Let <var>callerContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16669"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Suspend <var>callerContext</var>.</li><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> to <emu-const>executing</emu-const>.</li><li>Push <var>genContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16670"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>genContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16671"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><span class="e-user-code">Resume the suspended evaluation of <var>genContext</var></span> using <var>completion</var> as the result of the operation that suspended it. Let <var>result</var> be the <emu-xref href="#sec-completion-record-specification-type" id="_ref_16672"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> returned by the resumed computation.</li><li><emu-xref href="#assert" id="_ref_16673"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>result</var> is never an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16674"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>.</li><li><emu-xref href="#assert" id="_ref_16675"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: When we return here, <var>genContext</var> has already been removed from the <emu-xref href="#execution-context-stack" id="_ref_16676"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and <var>callerContext</var> is the currently <emu-xref href="#running-execution-context" id="_ref_16677"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratorunwrapyieldresumption" type="abstract operation" aoid="AsyncGeneratorUnwrapYieldResumption">
<h1><span class="secnum">27.6.3.7</span> AsyncGeneratorUnwrapYieldResumption ( <var>resumptionValue</var> )</h1>
<p>The abstract operation AsyncGeneratorUnwrapYieldResumption takes argument <var>resumptionValue</var> (a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16678"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16679"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16680"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16681"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>If <var>resumptionValue</var> is not a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16682"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>, return ?&nbsp;<var>resumptionValue</var>.</li><li>Let <var>awaited</var> be <emu-xref aoid="Completion" id="_ref_16683"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Await" id="_ref_16684"><a href="control-abstraction-objects.html#await" class="e-user-code">Await</a></emu-xref>(<var>resumptionValue</var>.<var class="field">[[Value]]</var>)).</li><li>If <var>awaited</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16685"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>, return ?&nbsp;<var>awaited</var>.</li><li><emu-xref href="#assert" id="_ref_16686"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>awaited</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16687"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>.</li><li>Return <emu-xref aoid="ReturnCompletion" id="_ref_16688"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<var>awaited</var>.<var class="field">[[Value]]</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratoryield" type="abstract operation" aoid="AsyncGeneratorYield">
<h1><span class="secnum">27.6.3.8</span> AsyncGeneratorYield ( <var>value</var> )</h1>
<p>The abstract operation AsyncGeneratorYield takes argument <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16689"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16690"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16691"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16692"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>genContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16693"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><emu-xref href="#assert" id="_ref_16694"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>genContext</var> is the <emu-xref href="#sec-execution-contexts" id="_ref_16695"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> of a generator.</li><li>Let <var>generator</var> be the value of the Generator component of <var>genContext</var>.</li><li><emu-xref href="#assert" id="_ref_16696"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <emu-xref aoid="GetGeneratorKind" id="_ref_16697"><a href="control-abstraction-objects.html#sec-getgeneratorkind">GetGeneratorKind</a></emu-xref>() is <emu-const>async</emu-const>.</li><li>Let <var>completion</var> be <emu-xref aoid="NormalCompletion" id="_ref_16698"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>value</var>).</li><li><emu-xref href="#assert" id="_ref_16699"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: The <emu-xref href="#execution-context-stack" id="_ref_16700"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> has at least two elements.</li><li>Let <var>previousContext</var> be the second to top element of the <emu-xref href="#execution-context-stack" id="_ref_16701"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>.</li><li>Let <var>previousRealm</var> be <var>previousContext</var>'s <emu-xref href="#realm" id="_ref_16702"><a href="executable-code-and-execution-contexts.html#realm">Realm</a></emu-xref>.</li><li>Perform <emu-xref aoid="AsyncGeneratorCompleteStep" id="_ref_16703"><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" class="e-user-code">AsyncGeneratorCompleteStep</a></emu-xref>(<var>generator</var>, <var>completion</var>, <emu-val>false</emu-val>, <var>previousRealm</var>).</li><li>Let <var>queue</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var>.</li><li>If <var>queue</var> is not empty, then<ol><li>NOTE: Execution continues without suspending the generator.</li><li>Let <var>toYield</var> be the first element of <var>queue</var>.</li><li>Let <var>resumptionValue</var> be <emu-xref aoid="Completion" id="_ref_16704"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<var>toYield</var>.<var class="field">[[Completion]]</var>).</li><li>Return ?&nbsp;<emu-xref aoid="AsyncGeneratorUnwrapYieldResumption" id="_ref_16705"><a href="control-abstraction-objects.html#sec-asyncgeneratorunwrapyieldresumption" class="e-user-code">AsyncGeneratorUnwrapYieldResumption</a></emu-xref>(<var>resumptionValue</var>).</li></ol></li><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> to <emu-const>suspended-yield</emu-const>.</li><li>Remove <var>genContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16706"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore the <emu-xref href="#sec-execution-contexts" id="_ref_16707"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is at the top of the <emu-xref href="#execution-context-stack" id="_ref_16708"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> as the <emu-xref href="#running-execution-context" id="_ref_16709"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>callerContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16710"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Resume <var>callerContext</var> passing <emu-val>undefined</emu-val>. If <var>genContext</var> is ever resumed again, let <var>resumptionValue</var> be the <emu-xref href="#sec-completion-record-specification-type" id="_ref_16711"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> with which it is resumed.</li><li><emu-xref href="#assert" id="_ref_16712"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: If control reaches here, then <var>genContext</var> is the <emu-xref href="#running-execution-context" id="_ref_16713"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref> again.</li><li>Return ?&nbsp;<emu-xref aoid="AsyncGeneratorUnwrapYieldResumption" id="_ref_16714"><a href="control-abstraction-objects.html#sec-asyncgeneratorunwrapyieldresumption" class="e-user-code">AsyncGeneratorUnwrapYieldResumption</a></emu-xref>(<var>resumptionValue</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratorawaitreturn" type="abstract operation" aoid="AsyncGeneratorAwaitReturn">
<h1><span class="secnum">27.6.3.9</span> AsyncGeneratorAwaitReturn ( <var>generator</var> )</h1>
<p>The abstract operation AsyncGeneratorAwaitReturn takes argument <var>generator</var> (an AsyncGenerator) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16715"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> is <emu-const>draining-queue</emu-const>.</li><li>Let <var>queue</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var>.</li><li><emu-xref href="#assert" id="_ref_16716"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>queue</var> is not empty.</li><li>Let <var>next</var> be the first element of <var>queue</var>.</li><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_16717"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<var>next</var>.<var class="field">[[Completion]]</var>).</li><li><emu-xref href="#assert" id="_ref_16718"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>completion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16719"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>.</li><li>Let <var>promiseCompletion</var> be <emu-xref aoid="Completion" id="_ref_16720"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PromiseResolve" id="_ref_16721"><a href="control-abstraction-objects.html#sec-promise-resolve" class="e-user-code">PromiseResolve</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_16722"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>, <var>completion</var>.<var class="field">[[Value]]</var>)).</li><li>If <var>promiseCompletion</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_16723"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Perform <emu-xref aoid="AsyncGeneratorCompleteStep" id="_ref_16724"><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" class="e-user-code">AsyncGeneratorCompleteStep</a></emu-xref>(<var>generator</var>, <var>promiseCompletion</var>, <emu-val>true</emu-val>).</li><li>Perform <emu-xref aoid="AsyncGeneratorDrainQueue" id="_ref_16725"><a href="control-abstraction-objects.html#sec-asyncgeneratordrainqueue" class="e-user-code">AsyncGeneratorDrainQueue</a></emu-xref>(<var>generator</var>).</li><li>Return <emu-const>unused</emu-const>.</li></ol></li><li><emu-xref href="#assert" id="_ref_16726"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>promiseCompletion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16727"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>.</li><li>Let <var>promise</var> be <var>promiseCompletion</var>.<var class="field">[[Value]]</var>.</li><li>Let <var>fulfilledClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16728"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>value</var>) that captures <var>generator</var> and performs the following steps when called:<ol><li><emu-xref href="#assert" id="_ref_16729"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> is <emu-const>draining-queue</emu-const>.</li><li>Let <var>result</var> be <emu-xref aoid="NormalCompletion" id="_ref_16730"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>value</var>).</li><li>Perform <emu-xref aoid="AsyncGeneratorCompleteStep" id="_ref_16731"><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" class="e-user-code">AsyncGeneratorCompleteStep</a></emu-xref>(<var>generator</var>, <var>result</var>, <emu-val>true</emu-val>).</li><li>Perform <emu-xref aoid="AsyncGeneratorDrainQueue" id="_ref_16732"><a href="control-abstraction-objects.html#sec-asyncgeneratordrainqueue" class="e-user-code">AsyncGeneratorDrainQueue</a></emu-xref>(<var>generator</var>).</li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16733"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Let <var>onFulfilled</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16734"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>fulfilledClosure</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Let <var>rejectedClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16735"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>reason</var>) that captures <var>generator</var> and performs the following steps when called:<ol><li><emu-xref href="#assert" id="_ref_16736"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> is <emu-const>draining-queue</emu-const>.</li><li>Let <var>result</var> be <emu-xref aoid="ThrowCompletion" id="_ref_16737"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>reason</var>).</li><li>Perform <emu-xref aoid="AsyncGeneratorCompleteStep" id="_ref_16738"><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" class="e-user-code">AsyncGeneratorCompleteStep</a></emu-xref>(<var>generator</var>, <var>result</var>, <emu-val>true</emu-val>).</li><li>Perform <emu-xref aoid="AsyncGeneratorDrainQueue" id="_ref_16739"><a href="control-abstraction-objects.html#sec-asyncgeneratordrainqueue" class="e-user-code">AsyncGeneratorDrainQueue</a></emu-xref>(<var>generator</var>).</li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16740"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Let <var>onRejected</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16741"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>rejectedClosure</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Perform <emu-xref aoid="PerformPromiseThen" id="_ref_16742"><a href="control-abstraction-objects.html#sec-performpromisethen">PerformPromiseThen</a></emu-xref>(<var>promise</var>, <var>onFulfilled</var>, <var>onRejected</var>).</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncgeneratordrainqueue" type="abstract operation" aoid="AsyncGeneratorDrainQueue">
<h1><span class="secnum">27.6.3.10</span> AsyncGeneratorDrainQueue ( <var>generator</var> )</h1>
<p>The abstract operation AsyncGeneratorDrainQueue takes argument <var>generator</var> (an AsyncGenerator) and returns <emu-const>unused</emu-const>. It drains the generator's AsyncGeneratorQueue until it encounters an <emu-xref href="#sec-asyncgeneratorrequest-records" id="_ref_16743"><a href="control-abstraction-objects.html#sec-asyncgeneratorrequest-records">AsyncGeneratorRequest</a></emu-xref> which holds a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16744"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_16745"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> is <emu-const>draining-queue</emu-const>.</li><li>Let <var>queue</var> be <var>generator</var>.<var class="field">[[AsyncGeneratorQueue]]</var>.</li><li>Repeat, while <var>queue</var> is not empty,<ol><li>Let <var>next</var> be the first element of <var>queue</var>.</li><li>Let <var>completion</var> be <emu-xref aoid="Completion" id="_ref_16746"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<var>next</var>.<var class="field">[[Completion]]</var>).</li><li>If <var>completion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16747"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>, then<ol><li>Perform <emu-xref aoid="AsyncGeneratorAwaitReturn" id="_ref_16748"><a href="control-abstraction-objects.html#sec-asyncgeneratorawaitreturn" class="e-user-code">AsyncGeneratorAwaitReturn</a></emu-xref>(<var>generator</var>).</li><li>Return <emu-const>unused</emu-const>.</li></ol></li><li>If <var>completion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16749"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, then<ol><li>Set <var>completion</var> to <emu-xref aoid="NormalCompletion" id="_ref_16750"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Perform <emu-xref aoid="AsyncGeneratorCompleteStep" id="_ref_16751"><a href="control-abstraction-objects.html#sec-asyncgeneratorcompletestep" class="e-user-code">AsyncGeneratorCompleteStep</a></emu-xref>(<var>generator</var>, <var>completion</var>, <emu-val>true</emu-val>).</li></ol></li><li>Set <var>generator</var>.<var class="field">[[AsyncGeneratorState]]</var> to <emu-const>completed</emu-const>.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-async-function-objects">
<h1><span class="secnum">27.7</span> AsyncFunction Objects</h1>
<p>AsyncFunctions are functions that are usually created by evaluating <emu-nt id="_ref_24563"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncFunctionDeclaration">AsyncFunctionDeclaration</a></emu-nt>s, <emu-nt id="_ref_24564"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncFunctionExpression">AsyncFunctionExpression</a></emu-nt>s, <emu-nt id="_ref_24565"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncMethod">AsyncMethod</a></emu-nt>s, and <emu-nt id="_ref_24566"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncArrowFunction">AsyncArrowFunction</a></emu-nt>s. They may also be created by calling the <emu-xref href="#sec-async-function-constructor" id="_ref_16752"><a href="control-abstraction-objects.html#sec-async-function-constructor">%AsyncFunction%</a></emu-xref> intrinsic.</p>
<emu-clause id="sec-async-function-constructor">
<h1><span class="secnum">27.7.1</span> The AsyncFunction Constructor</h1>
<p>The AsyncFunction <emu-xref href="#constructor" id="_ref_16753"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is <dfn tabindex="-1">%AsyncFunction%</dfn>.</li>
<li>is a subclass of <code>Function</code>.</li>
<li>creates and initializes a new AsyncFunction when called as a function rather than as a <emu-xref href="#constructor" id="_ref_16754"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>. Thus the function call <code>AsyncFunction(…)</code> is equivalent to the object creation expression <code>new AsyncFunction(…)</code> with the same arguments.</li>
<li>may be used as the value of an <code>extends</code> clause of a class definition. Subclass <emu-xref href="#constructor" id="_ref_16755"><a href="ecmascript-data-types-and-values.html#constructor">constructors</a></emu-xref> that intend to inherit the specified AsyncFunction behaviour must include a <code>super</code> call to the AsyncFunction <emu-xref href="#constructor" id="_ref_16756"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref> to create and initialize a subclass instance with the internal slots necessary for built-in async function behaviour. All ECMAScript syntactic forms for defining async <emu-xref href="#function-object" id="_ref_16757"><a href="ecmascript-data-types-and-values.html#function-object">function objects</a></emu-xref> create direct instances of AsyncFunction. There is no syntactic means to create instances of AsyncFunction subclasses.</li>
</ul>
<emu-clause id="sec-async-function-constructor-arguments" type="built-in function">
<h1><span class="secnum">27.7.1.1</span> AsyncFunction ( ...<var>parameterArgs</var>, <var>bodyArg</var> )</h1>
<p>The last argument (if any) specifies the body (executable code) of an async function. Any preceding arguments specify formal parameters.</p>
<p>This function performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>C</var> be the <emu-xref href="#active-function-object" id="_ref_16758"><a href="executable-code-and-execution-contexts.html#active-function-object">active function object</a></emu-xref>.</li><li>If <var>bodyArg</var> is not present, set <var>bodyArg</var> to the empty String.</li><li>Return ?&nbsp;<emu-xref aoid="CreateDynamicFunction" id="_ref_16759"><a href="fundamental-objects.html#sec-createdynamicfunction" class="e-user-code">CreateDynamicFunction</a></emu-xref>(<var>C</var>, NewTarget, <emu-const>async</emu-const>, <var>parameterArgs</var>, <var>bodyArg</var>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">See NOTE for <emu-xref href="#sec-function-p1-p2-pn-body" id="_ref_842"><a href="fundamental-objects.html#sec-function-p1-p2-pn-body">20.2.1.1</a></emu-xref>.</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-async-function-constructor-properties">
<h1><span class="secnum">27.7.2</span> Properties of the AsyncFunction Constructor</h1>
<p>The AsyncFunction <emu-xref href="#constructor" id="_ref_16760"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>:</p>
<ul>
<li>is a standard built-in <emu-xref href="#function-object" id="_ref_16761"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> that inherits from the Function <emu-xref href="#constructor" id="_ref_16762"><a href="ecmascript-data-types-and-values.html#constructor">constructor</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-function-constructor" id="_ref_16763"><a href="fundamental-objects.html#sec-function-constructor">%Function%</a></emu-xref>.</li>
<li oldids="sec-async-function-constructor-length"><span id="sec-async-function-constructor-length"></span>has a <emu-val>"length"</emu-val> property whose value is <emu-val>1</emu-val><sub>𝔽</sub>.</li>
<li>has a <emu-val>"name"</emu-val> property whose value is <emu-val>"AsyncFunction"</emu-val>.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-async-function-constructor-prototype">
<h1><span class="secnum">27.7.2.1</span> AsyncFunction.prototype</h1>
<p>The initial value of <code>AsyncFunction.prototype</code> is the <emu-xref href="#sec-async-function-prototype-properties" id="_ref_16764"><a href="control-abstraction-objects.html#sec-async-function-prototype-properties">AsyncFunction prototype object</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>false</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-async-function-prototype-properties">
<h1><span class="secnum">27.7.3</span> Properties of the AsyncFunction Prototype Object</h1>
<p>The <dfn tabindex="-1">AsyncFunction prototype object</dfn>:</p>
<ul>
<li>is <dfn tabindex="-1">%AsyncFunction.prototype%</dfn>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_16765"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary object</a></emu-xref>.</li>
<li>is not a <emu-xref href="#function-object" id="_ref_16766"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> and does not have an <var class="field">[[ECMAScriptCode]]</var> internal slot or any other of the internal slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects" id="_ref_843"><a href="ordinary-and-exotic-objects-behaviours.html#table-internal-slots-of-ecmascript-function-objects">Table 25</a></emu-xref>.</li>
<li>has a <var class="field">[[Prototype]]</var> internal slot whose value is <emu-xref href="#sec-properties-of-the-function-prototype-object" id="_ref_16767"><a href="fundamental-objects.html#sec-properties-of-the-function-prototype-object">%Function.prototype%</a></emu-xref>.</li>
</ul>
<emu-clause id="sec-async-function-prototype-properties-constructor">
<h1><span class="secnum">27.7.3.1</span> AsyncFunction.prototype.constructor</h1>
<p>The initial value of <code>AsyncFunction.prototype.constructor</code> is <emu-xref href="#sec-async-function-constructor" id="_ref_16768"><a href="control-abstraction-objects.html#sec-async-function-constructor">%AsyncFunction%</a></emu-xref>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
<emu-clause oldids="sec-async-function-prototype-properties-toStringTag" id="sec-async-function-prototype-%symbol.tostringtag%"><span id="sec-async-function-prototype-properties-toStringTag"></span>
<h1><span class="secnum">27.7.3.2</span> AsyncFunction.prototype [ %Symbol.toStringTag% ]</h1>
<p>The initial value of the <emu-xref href="#sec-well-known-symbols" id="_ref_16769"><a href="ecmascript-data-types-and-values.html#sec-well-known-symbols">%Symbol.toStringTag%</a></emu-xref> property is the String value <emu-val>"AsyncFunction"</emu-val>.</p>
<p>This property has the attributes { <var class="field">[[Writable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Enumerable]]</var>: <emu-val>false</emu-val>, <var class="field">[[Configurable]]</var>: <emu-val>true</emu-val> }.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-async-function-instances">
<h1><span class="secnum">27.7.4</span> AsyncFunction Instances</h1>
<p>Every AsyncFunction instance is an ECMAScript <emu-xref href="#function-object" id="_ref_16770"><a href="ecmascript-data-types-and-values.html#function-object">function object</a></emu-xref> and has the internal slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects" id="_ref_844"><a href="ordinary-and-exotic-objects-behaviours.html#table-internal-slots-of-ecmascript-function-objects">Table 25</a></emu-xref>. The value of the <var class="field">[[IsClassConstructor]]</var> internal slot for all such instances is <emu-val>false</emu-val>. AsyncFunction instances are not <emu-xref href="#constructor" id="_ref_16771"><a href="ecmascript-data-types-and-values.html#constructor">constructors</a></emu-xref> and do not have a <var class="field">[[Construct]]</var> internal method. AsyncFunction instances do not have a prototype property as they are not constructable.</p>
<p>Each AsyncFunction instance has the following own properties:</p>
<emu-clause id="sec-async-function-instances-length">
<h1><span class="secnum">27.7.4.1</span> length</h1>
<p>The specification for the <emu-val>"length"</emu-val> property of Function instances given in <emu-xref href="#sec-function-instances-length" id="_ref_845"><a href="fundamental-objects.html#sec-function-instances-length">20.2.4.1</a></emu-xref> also applies to AsyncFunction instances.</p>
</emu-clause>
<emu-clause id="sec-async-function-instances-name">
<h1><span class="secnum">27.7.4.2</span> name</h1>
<p>The specification for the <emu-val>"name"</emu-val> property of Function instances given in <emu-xref href="#sec-function-instances-name" id="_ref_846"><a href="fundamental-objects.html#sec-function-instances-name">20.2.4.2</a></emu-xref> also applies to AsyncFunction instances.</p>
</emu-clause>
</emu-clause>
<emu-clause id="sec-async-functions-abstract-operations">
<h1><span class="secnum">27.7.5</span> Async Functions Abstract Operations</h1>
<emu-clause id="sec-async-functions-abstract-operations-async-function-start" type="abstract operation" aoid="AsyncFunctionStart">
<h1><span class="secnum">27.7.5.1</span> AsyncFunctionStart ( <var>promiseCapability</var>, <var>asyncFunctionBody</var> )</h1>
<p>The abstract operation AsyncFunctionStart takes arguments <var>promiseCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16772"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>) and <var>asyncFunctionBody</var> (a <emu-nt id="_ref_24567"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionBody">FunctionBody</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_16773"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>, an <emu-nt id="_ref_24568"><a href="ecmascript-language-functions-and-classes.html#prod-ExpressionBody">ExpressionBody</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_16774"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>, or an <emu-xref href="#sec-abstract-closure" id="_ref_16775"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>runningContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16776"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>asyncContext</var> be a copy of <var>runningContext</var>.</li><li>NOTE: Copying the execution state is required for <emu-xref aoid="AsyncBlockStart" id="_ref_16777"><a href="control-abstraction-objects.html#sec-asyncblockstart">AsyncBlockStart</a></emu-xref> to resume its execution. It is ill-defined to resume a currently executing context.</li><li>Perform <emu-xref aoid="AsyncBlockStart" id="_ref_16778"><a href="control-abstraction-objects.html#sec-asyncblockstart" class="e-user-code">AsyncBlockStart</a></emu-xref>(<var>promiseCapability</var>, <var>asyncFunctionBody</var>, <var>asyncContext</var>).</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-asyncblockstart" type="abstract operation" aoid="AsyncBlockStart">
<h1><span class="secnum">27.7.5.2</span> AsyncBlockStart ( <var>promiseCapability</var>, <var>asyncBody</var>, <var>asyncContext</var> )</h1>
<p>The abstract operation AsyncBlockStart takes arguments <var>promiseCapability</var> (a <emu-xref href="#sec-promisecapability-records" id="_ref_16779"><a href="control-abstraction-objects.html#sec-promisecapability-records">PromiseCapability Record</a></emu-xref>), <var>asyncBody</var> (a <emu-xref href="#sec-syntactic-grammar" id="_ref_16780"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> or an <emu-xref href="#sec-abstract-closure" id="_ref_16781"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters), and <var>asyncContext</var> (an <emu-xref href="#sec-execution-contexts" id="_ref_16782"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref>) and returns <emu-const>unused</emu-const>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>runningContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16783"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>closure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16784"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters that captures <var>promiseCapability</var> and <var>asyncBody</var> and performs the following steps when called:<ol><li>Let <var>acAsyncContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16785"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>If <var>asyncBody</var> is a <emu-xref href="#sec-syntactic-grammar" id="_ref_16786"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>, then<ol><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16787"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_16788"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>asyncBody</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16789"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>asyncBody</var> is an <emu-xref href="#sec-abstract-closure" id="_ref_16790"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with no parameters.</li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_16791"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<var>asyncBody</var>()).</li></ol></li><li><emu-xref href="#assert" id="_ref_16792"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: If we return here, the async function either threw an exception or performed an implicit or explicit return; all awaiting is done.</li><li>Remove <var>acAsyncContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16793"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore the <emu-xref href="#sec-execution-contexts" id="_ref_16794"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is at the top of the <emu-xref href="#execution-context-stack" id="_ref_16795"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> as the <emu-xref href="#running-execution-context" id="_ref_16796"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>If <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16797"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, then<ol><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16798"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <emu-val>undefined</emu-val>&nbsp;»).</li></ol></li><li>Else if <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16799"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">return completion</a></emu-xref>, then<ol><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16800"><a href="abstract-operations.html#sec-call" class="e-user-code e-user-code">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Resolve]]</var>, <emu-val>undefined</emu-val>, « <var>result</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_16801"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16802"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>.</li><li>Perform !&nbsp;<emu-xref aoid="Call" id="_ref_16803"><a href="abstract-operations.html#sec-call">Call</a></emu-xref>(<var>promiseCapability</var>.<var class="field">[[Reject]]</var>, <emu-val>undefined</emu-val>, « <var>result</var>.<var class="field">[[Value]]</var>&nbsp;»).</li></ol></li><li id="step-asyncblockstart-return-undefined">Return <emu-xref aoid="NormalCompletion" id="_ref_16804"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-const>unused</emu-const>).</li></ol></li><li>Set the code evaluation state of <var>asyncContext</var> such that when evaluation is resumed for that <emu-xref href="#sec-execution-contexts" id="_ref_16805"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref>, <var>closure</var> will be called with no arguments.</li><li>Push <var>asyncContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16806"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>asyncContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16807"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><span class="e-user-code">Resume the suspended evaluation of <var>asyncContext</var></span>. Let <var>result</var> be the value returned by the resumed computation.</li><li><emu-xref href="#assert" id="_ref_16808"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: When we return here, <var>asyncContext</var> has already been removed from the <emu-xref href="#execution-context-stack" id="_ref_16809"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and <var>runningContext</var> is the currently <emu-xref href="#running-execution-context" id="_ref_16810"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><emu-xref href="#assert" id="_ref_16811"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>result</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16812"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref> with a value of <emu-const>unused</emu-const>. The possible sources of this value are <emu-xref aoid="Await" id="_ref_16813"><a href="control-abstraction-objects.html#await">Await</a></emu-xref> or, if the async function doesn't await anything, step <emu-xref href="#step-asyncblockstart-return-undefined" id="_ref_847"><a href="control-abstraction-objects.html#step-asyncblockstart-return-undefined">2.i</a></emu-xref> above.</li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="await" oldids="await-fulfilled,await-rejected" type="abstract operation" aoid="Await"><span id="await-rejected"></span><span id="await-fulfilled"></span>
<h1><span class="secnum">27.7.5.3</span> Await ( <var>value</var> )</h1>
<p>The abstract operation Await takes argument <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16814"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16815"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> either an <emu-xref href="#sec-ecmascript-language-types" id="_ref_16816"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref> or <emu-const>empty</emu-const>, or a <emu-xref href="#sec-completion-record-specification-type" id="_ref_16817"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>asyncContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16818"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>promise</var> be ?&nbsp;<emu-xref aoid="PromiseResolve" id="_ref_16819"><a href="control-abstraction-objects.html#sec-promise-resolve" class="e-user-code">PromiseResolve</a></emu-xref>(<emu-xref href="#sec-promise-constructor" id="_ref_16820"><a href="control-abstraction-objects.html#sec-promise-constructor">%Promise%</a></emu-xref>, <var>value</var>).</li><li>Let <var>fulfilledClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16821"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>v</var>) that captures <var>asyncContext</var> and performs the following steps when called:<ol><li>Let <var>prevContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16822"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Suspend <var>prevContext</var>.</li><li>Push <var>asyncContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16823"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>asyncContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16824"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><span class="e-user-code">Resume the suspended evaluation of <var>asyncContext</var></span> using <emu-xref aoid="NormalCompletion" id="_ref_16825"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>v</var>) as the result of the operation that suspended it.</li><li><emu-xref href="#assert" id="_ref_16826"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: When we reach this step, <var>asyncContext</var> has already been removed from the <emu-xref href="#execution-context-stack" id="_ref_16827"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and <var>prevContext</var> is the currently <emu-xref href="#running-execution-context" id="_ref_16828"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16829"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Let <var>onFulfilled</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16830"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>fulfilledClosure</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Let <var>rejectedClosure</var> be a new <emu-xref href="#sec-abstract-closure" id="_ref_16831"><a href="ecmascript-data-types-and-values.html#sec-abstract-closure">Abstract Closure</a></emu-xref> with parameters (<var>reason</var>) that captures <var>asyncContext</var> and performs the following steps when called:<ol><li>Let <var>prevContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16832"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Suspend <var>prevContext</var>.</li><li>Push <var>asyncContext</var> onto the <emu-xref href="#execution-context-stack" id="_ref_16833"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref>; <var>asyncContext</var> is now the <emu-xref href="#running-execution-context" id="_ref_16834"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li><span class="e-user-code">Resume the suspended evaluation of <var>asyncContext</var></span> using <emu-xref aoid="ThrowCompletion" id="_ref_16835"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>reason</var>) as the result of the operation that suspended it.</li><li><emu-xref href="#assert" id="_ref_16836"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: When we reach this step, <var>asyncContext</var> has already been removed from the <emu-xref href="#execution-context-stack" id="_ref_16837"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and <var>prevContext</var> is the currently <emu-xref href="#running-execution-context" id="_ref_16838"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Return <emu-xref aoid="NormalCompletion" id="_ref_16839"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></li><li>Let <var>onRejected</var> be <emu-xref aoid="CreateBuiltinFunction" id="_ref_16840"><a href="ordinary-and-exotic-objects-behaviours.html#sec-createbuiltinfunction">CreateBuiltinFunction</a></emu-xref>(<var>rejectedClosure</var>, 1, <emu-val>""</emu-val>, «&nbsp;»).</li><li>Perform <emu-xref aoid="PerformPromiseThen" id="_ref_16841"><a href="control-abstraction-objects.html#sec-performpromisethen">PerformPromiseThen</a></emu-xref>(<var>promise</var>, <var>onFulfilled</var>, <var>onRejected</var>).</li><li>Remove <var>asyncContext</var> from the <emu-xref href="#execution-context-stack" id="_ref_16842"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> and restore the <emu-xref href="#sec-execution-contexts" id="_ref_16843"><a href="executable-code-and-execution-contexts.html#sec-execution-contexts">execution context</a></emu-xref> that is at the top of the <emu-xref href="#execution-context-stack" id="_ref_16844"><a href="executable-code-and-execution-contexts.html#execution-context-stack">execution context stack</a></emu-xref> as the <emu-xref href="#running-execution-context" id="_ref_16845"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Let <var>callerContext</var> be the <emu-xref href="#running-execution-context" id="_ref_16846"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>.</li><li>Resume <var>callerContext</var> passing <emu-const>empty</emu-const>. If <var>asyncContext</var> is ever resumed again, let <var>completion</var> be the <emu-xref href="#sec-completion-record-specification-type" id="_ref_16847"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> with which it is resumed.</li><li><emu-xref href="#assert" id="_ref_16848"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: If control reaches here, then <var>asyncContext</var> is the <emu-xref href="#running-execution-context" id="_ref_16849"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref> again.</li><li>Return <var>completion</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
</emu-clause></div></body>
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