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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">
<link rel="icon" href="../img/favicon.ico">
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/**
* ECMA-262-specific hacks. Shouldn't require a ton of maintenance; audit if
* visual inspection results in unexpected page breaks.
*
* For print version, the table captioned "Module fields after the initial Evaluate() call" _may_ need to set the row
* EVALUATING-ASYNC to one cell with a colspan of 5. It typically does not fit on the page, but the cell merging is
* not a perfectly accurate solution and will not be merged back in to the specification.
* See https://github.com/tc39/ecma262/pull/3623#issuecomment-3029366960
*/
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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><style>
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</style><link rel="canonical" href="../#sec-ecmascript-language-statements-and-declarations"></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> 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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 href="fundamental-objects.html#sec-function.prototype.call" title="Function.prototype.call ( thisArg, ...args )"><span class="secnum">20.2.3.3</span> Function.prototype.call ( <var>thisArg</var>, ...<var>args</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function.prototype.constructor" title="Function.prototype.constructor"><span class="secnum">20.2.3.4</span> Function.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function.prototype.tostring" title="Function.prototype.toString ( )"><span class="secnum">20.2.3.5</span> Function.prototype.toString ( )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-function.prototype-%symbol.hasinstance%" title="Function.prototype [ %Symbol.hasInstance% ] ( V )"><span class="secnum">20.2.3.6</span> Function.prototype [ %Symbol.hasInstance% ] ( <var>V</var> )</a></li></ol></li><li><span 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 class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-error-constructor" title="Properties of the Error Constructor"><span class="secnum">20.5.2</span> Properties of the Error Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-error.iserror" title="Error.isError ( arg )"><span class="secnum">20.5.2.1</span> Error.isError ( <var>arg</var> )</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-error.prototype" title="Error.prototype"><span class="secnum">20.5.2.2</span> Error.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-error-prototype-object" title="Properties of the Error Prototype Object"><span class="secnum">20.5.3</span> Properties of the Error Prototype Object</a><ol class="toc"><li><span class="item-toggle-none"></span><a 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 Error Instances</a></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard" title="Native Error Types Used in This Standard"><span class="secnum">20.5.5</span> Native Error Types Used in This Standard</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard-evalerror" title="EvalError"><span class="secnum">20.5.5.1</span> EvalError</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard-rangeerror" title="RangeError"><span class="secnum">20.5.5.2</span> RangeError</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard-referenceerror" title="ReferenceError"><span class="secnum">20.5.5.3</span> ReferenceError</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard-syntaxerror" title="SyntaxError"><span class="secnum">20.5.5.4</span> SyntaxError</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard-typeerror" title="TypeError"><span class="secnum">20.5.5.5</span> TypeError</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-native-error-types-used-in-this-standard-urierror" title="URIError"><span class="secnum">20.5.5.6</span> URIError</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-nativeerror-object-structure" title="NativeError Object Structure"><span class="secnum">20.5.6</span> <var>NativeError</var> Object Structure</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-nativeerror-constructors" title="The NativeError Constructors"><span class="secnum">20.5.6.1</span> The <var>NativeError</var> Constructors</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-nativeerror" title="NativeError ( message [ , options ] )"><span class="secnum">20.5.6.1.1</span> <var>NativeError</var> ( <var>message</var> [ , <var>options</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-nativeerror-constructors" title="Properties of the NativeError Constructors"><span class="secnum">20.5.6.2</span> Properties of the <var>NativeError</var> Constructors</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-nativeerror.prototype" title="NativeError.prototype"><span class="secnum">20.5.6.2.1</span> <var>NativeError</var>.prototype</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-nativeerror-prototype-objects" title="Properties of the NativeError Prototype Objects"><span class="secnum">20.5.6.3</span> Properties of the <var>NativeError</var> Prototype Objects</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-nativeerror.prototype.constructor" title="NativeError.prototype.constructor"><span class="secnum">20.5.6.3.1</span> <var>NativeError</var>.prototype.constructor</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-nativeerror.prototype.message" title="NativeError.prototype.message"><span class="secnum">20.5.6.3.2</span> <var>NativeError</var>.prototype.message</a></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-nativeerror.prototype.name" title="NativeError.prototype.name"><span class="secnum">20.5.6.3.3</span> <var>NativeError</var>.prototype.name</a></li></ol></li><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-properties-of-nativeerror-instances" title="Properties of NativeError Instances"><span class="secnum">20.5.6.4</span> Properties of <var>NativeError</var> Instances</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-aggregate-error-objects" title="AggregateError Objects"><span class="secnum">20.5.7</span> AggregateError Objects</a><ol class="toc"><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-aggregate-error-constructor" title="The AggregateError Constructor"><span class="secnum">20.5.7.1</span> The AggregateError Constructor</a><ol class="toc"><li><span class="item-toggle-none"></span><a href="fundamental-objects.html#sec-aggregate-error" title="AggregateError ( errors, message [ , options ] )"><span class="secnum">20.5.7.1.1</span> AggregateError ( <var>errors</var>, <var>message</var> [ , <var>options</var> ] )</a></li></ol></li><li><span class="item-toggle">+</span><a href="fundamental-objects.html#sec-properties-of-the-aggregate-error-constructors" title="Properties of the 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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<h1><span class="secnum">14</span> ECMAScript Language: Statements and Declarations</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="Statement" params="Yield, Await, Return" id="prod-Statement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ktzsppzs" id="prod-c1cDILr5">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21401"><a href="ecmascript-language-statements-and-declarations.html#prod-BlockStatement">BlockStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="xumq1cs6" id="prod-PfH00D1w">
<emu-nt params="?Yield, ?Await" id="_ref_21402"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableStatement">VariableStatement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="cziqu-45" id="prod-YqiTL09y">
<emu-nt id="_ref_21403"><a href="ecmascript-language-statements-and-declarations.html#prod-EmptyStatement">EmptyStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="vt4s4xgg" id="prod-WCz7iwtm">
<emu-nt params="?Yield, ?Await" id="_ref_21404"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="vpvr9yr3" id="prod-jug3e433">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21405"><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="3kwmhgcn">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21406"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="klxmhdlm" id="prod-Ro8XgDsH">
<emu-nt params="?Yield, ?Await" id="_ref_21407"><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="vtt-myod" id="prod-Rrel7YUC">
<emu-nt params="?Yield, ?Await" id="_ref_21408"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="1sriw0nt" constraints="+Return" id="prod-twdIgE_o"><emu-constraints>[+Return]</emu-constraints>
<emu-nt params="?Yield, ?Await" id="_ref_21409"><a href="ecmascript-language-statements-and-declarations.html#prod-ReturnStatement">ReturnStatement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="_gejjak9" id="prod-xepAqppR">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21410"><a href="ecmascript-language-statements-and-declarations.html#prod-WithStatement">WithStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="90_gq6ig">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21411"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="ukgcnqlt" id="prod-GHPcIp4f">
<emu-nt params="?Yield, ?Await" id="_ref_21412"><a href="ecmascript-language-statements-and-declarations.html#prod-ThrowStatement">ThrowStatement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="z7s8kfe1" id="prod-HB_2xdti">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21413"><a href="ecmascript-language-statements-and-declarations.html#prod-TryStatement">TryStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="iseu28qi" id="prod-bDeNjo3k">
<emu-nt id="_ref_21414"><a href="ecmascript-language-statements-and-declarations.html#prod-DebuggerStatement">DebuggerStatement</a></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="Declaration" params="Yield, Await" id="prod-Declaration">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-Declaration">Declaration</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="i6hr6ytb">
<emu-nt params="?Yield, ?Await, ~Default" id="_ref_21415"><a href="ecmascript-language-statements-and-declarations.html#prod-HoistableDeclaration">HoistableDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ~Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="jfshu5d-" id="prod-o4HYrPz3">
<emu-nt params="?Yield, ?Await, ~Default" id="_ref_21416"><a href="ecmascript-language-functions-and-classes.html#prod-ClassDeclaration">ClassDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ~Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="dl5lsw3w" id="prod-9H9FGeT7">
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21417"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="HoistableDeclaration" params="Yield, Await, Default" id="prod-HoistableDeclaration">
<emu-nt params="Yield, Await, Default"><a href="ecmascript-language-statements-and-declarations.html#prod-HoistableDeclaration">HoistableDeclaration</a><emu-mods><emu-params>[Yield, Await, Default]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="pm1iqgpt" id="prod-xo77HsL9">
<emu-nt params="?Yield, ?Await, ?Default" id="_ref_21418"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ?Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="rhqaxmir" id="prod-dpslEYBS">
<emu-nt params="?Yield, ?Await, ?Default" id="_ref_21419"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorDeclaration">GeneratorDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ?Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="3nfjki-g" id="prod-InkDjQLb">
<emu-nt params="?Yield, ?Await, ?Default" id="_ref_21420"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncFunctionDeclaration">AsyncFunctionDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ?Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="e-_qp6dd" id="prod-OBGQy9cZ">
<emu-nt params="?Yield, ?Await, ?Default" id="_ref_21421"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorDeclaration">AsyncGeneratorDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ?Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BreakableStatement" params="Yield, Await, Return" id="prod-BreakableStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="olmcy7ih" id="prod-IZrgrSFg">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21422"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="uzjzv-di" id="prod-r35GfF0W">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21423"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-statement-semantics">
<h1><span class="secnum">14.1</span> Statement Semantics</h1>
<emu-clause id="sec-statement-semantics-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.1.1</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="HoistableDeclaration">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-HoistableDeclaration">HoistableDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="r3zmbc2x" id="prod-F2xRdnbO">
<emu-nt id="_ref_21424"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorDeclaration">GeneratorDeclaration</a></emu-nt>
</emu-rhs>
<emu-rhs a="xi-jap6o" id="prod-19_kIcSj">
<emu-nt id="_ref_21425"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncFunctionDeclaration">AsyncFunctionDeclaration</a></emu-nt>
</emu-rhs>
<emu-rhs a="n353p_mm" id="prod-AdaKcE7P">
<emu-nt id="_ref_21426"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorDeclaration">AsyncGeneratorDeclaration</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="HoistableDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-HoistableDeclaration">HoistableDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="-nqupnlb" id="prod-80Y3L4PZ"><emu-nt id="_ref_21427"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6931"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21428"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt>.</li></ol></emu-alg>
<emu-grammar><emu-production name="BreakableStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="kmxl4yum" id="prod-FFjrmEWz">
<emu-nt id="_ref_21429"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="nuio-xfp" id="prod-cXJGjZtb">
<emu-nt id="_ref_21430"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>newLabelSet</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_6932"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Return ?&nbsp;<emu-xref aoid="LabelledEvaluation" id="_ref_6933"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-labelledevaluation" class="e-user-code">LabelledEvaluation</a></emu-xref> of this <emu-nt id="_ref_21431"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a></emu-nt> with argument <var>newLabelSet</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-block">
<h1><span class="secnum">14.2</span> Block</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="BlockStatement" params="Yield, Await, Return" id="prod-BlockStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-BlockStatement">BlockStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="zwpfwt4j">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21432"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="Block" params="Yield, Await, Return" id="prod-Block">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uij9rcu7" id="prod-30nvN6ck">
<emu-t>{</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" optional="" id="_ref_21433"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="StatementList" params="Yield, Await, Return" id="prod-StatementList">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="owubwn_s">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21434"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementListItem">StatementListItem</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="21clqs0p" id="prod--OFVjnjw">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21435"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21436"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementListItem">StatementListItem</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="StatementListItem" params="Yield, Await, Return" id="prod-StatementListItem">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementListItem">StatementListItem</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="septp5sa" id="prod-GHY4Vd3_">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21437"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="mtktetk8" id="prod-yYByJL6Z">
<emu-nt params="?Yield, ?Await" id="_ref_21438"><a href="ecmascript-language-statements-and-declarations.html#prod-Declaration">Declaration</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-block-static-semantics-early-errors" oldids="sec-block-duplicates-allowed-static-semantics"><span id="sec-block-duplicates-allowed-static-semantics"></span>
<h1><span class="secnum">14.2.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="Block" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="z4ljp0ar">
<emu-t>{</emu-t>
<emu-nt id="_ref_21439"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
<p>It is a Syntax Error if the <emu-xref aoid="LexicallyDeclaredNames" id="_ref_6934"><a href="syntax-directed-operations.html#sec-static-semantics-lexicallydeclarednames">LexicallyDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21440"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt> contains any duplicate entries<span normative-optional="">, unless the <emu-xref href="#host" id="_ref_6935"><a href="overview.html#host">host</a></emu-xref> is a web browser or otherwise supports <emu-xref href="#sec-block-level-function-declarations-web-legacy-compatibility-semantics" title="" id="_ref_440"><a href="additional-ecmascript-features-for-web-browsers.html#sec-block-level-function-declarations-web-legacy-compatibility-semantics">Block-Level Function Declarations Web Legacy Compatibility Semantics</a></emu-xref>, and both of the following conditions are true:</span></p>
<ul normative-optional="">
<li><emu-xref aoid="IsStrict" id="_ref_6936"><a href="ecmascript-language-source-code.html#sec-isstrict">IsStrict</a></emu-xref>(this production) is <emu-val>false</emu-val>.</li>
<li>The duplicate entries are only bound by FunctionDeclarations.</li>
</ul>
</li>
<li>
It is a Syntax Error if any element of the <emu-xref aoid="LexicallyDeclaredNames" id="_ref_6937"><a href="syntax-directed-operations.html#sec-static-semantics-lexicallydeclarednames">LexicallyDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21441"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt> also occurs in the <emu-xref aoid="VarDeclaredNames" id="_ref_6938"><a href="syntax-directed-operations.html#sec-static-semantics-vardeclarednames">VarDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21442"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-block-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.2.2</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="Block" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gbpaspne" id="prod-GN03td2O">
<emu-t>{</emu-t>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="Block" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="z4ljp0ar" id="prod-CUMWT9xI">
<emu-t>{</emu-t>
<emu-nt id="_ref_21443"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_6939"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>blockEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_6940"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>oldEnv</var>).</li><li>Perform <emu-xref aoid="BlockDeclarationInstantiation" id="_ref_6941"><a href="ecmascript-language-statements-and-declarations.html#sec-blockdeclarationinstantiation">BlockDeclarationInstantiation</a></emu-xref>(<emu-nt id="_ref_21444"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>, <var>blockEnv</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_6942"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>blockEnv</var>.</li><li>Let <var>blockValue</var> be <emu-xref aoid="Completion" id="_ref_6943"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_6944"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21445"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_6945"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return ?&nbsp;<var>blockValue</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>No matter how control leaves the <emu-nt id="_ref_21446"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt> the LexicalEnvironment is always restored to its former state.</p>
</div></emu-note>
<emu-grammar><emu-production name="StatementList" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="dbrzeh7l" id="prod-qY9k7-Mq">
<emu-nt id="_ref_21447"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>
<emu-nt id="_ref_21448"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementListItem">StatementListItem</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>sl</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6946"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21449"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>.</li><li>Let <var>s</var> be <emu-xref aoid="Completion" id="_ref_6947"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_6948"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21450"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementListItem">StatementListItem</a></emu-nt>).</li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_6949"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>s</var>, <var>sl</var>).</li></ol></emu-alg>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>The value of a <emu-nt id="_ref_21451"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt> is the value of the last value-producing item in the <emu-nt id="_ref_21452"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>. For example, the following calls to the <code>eval</code> function all return the value 1:</p>
<pre><code class="javascript hljs"><span class="hljs-built_in">eval</span>(<span class="hljs-string">"1;;;;;"</span>)
<span class="hljs-built_in">eval</span>(<span class="hljs-string">"1;{}"</span>)
<span class="hljs-built_in">eval</span>(<span class="hljs-string">"1;var a;"</span>)</code></pre>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-blockdeclarationinstantiation" type="abstract operation" oldids="sec-web-compat-blockdeclarationinstantiation" aoid="BlockDeclarationInstantiation"><span id="sec-web-compat-blockdeclarationinstantiation"></span>
<h1><span class="secnum">14.2.3</span> BlockDeclarationInstantiation ( <var>code</var>, <var>env</var> )</h1>
<p>The abstract operation BlockDeclarationInstantiation takes arguments <var>code</var> (a <emu-xref href="#sec-syntactic-grammar" id="_ref_6950"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>) and <var>env</var> (a <emu-xref href="#sec-declarative-environment-records" id="_ref_6951"><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records">Declarative Environment Record</a></emu-xref>) and returns <emu-const>unused</emu-const>. <var>code</var> is the <emu-xref href="#sec-syntactic-grammar" id="_ref_6952"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> corresponding to the body of the block. <var>env</var> is the <emu-xref href="#sec-environment-records" id="_ref_6953"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> in which bindings are to be created.</p>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>When a <emu-nt id="_ref_21453"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt> or <emu-nt id="_ref_21454"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> is evaluated a new <emu-xref href="#sec-declarative-environment-records" id="_ref_6954"><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records">Declarative Environment Record</a></emu-xref> is created and bindings for each block scoped variable, constant, function, or class declared in the block are instantiated in the <emu-xref href="#sec-environment-records" id="_ref_6955"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref>.</p>
</div></emu-note>
<p>It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>declarations</var> be the <emu-xref aoid="LexicallyScopedDeclarations" id="_ref_6958"><a href="syntax-directed-operations.html#sec-static-semantics-lexicallyscopeddeclarations">LexicallyScopedDeclarations</a></emu-xref> of <var>code</var>.</li><li>Let <var>privateEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_6959"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s PrivateEnvironment.</li><li>For each element <var>d</var> of <var>declarations</var>, do<ol><li>For each element <var>dn</var> of the <emu-xref aoid="BoundNames" id="_ref_6960"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <var>d</var>, do<ol><li>If <emu-xref aoid="IsConstantDeclaration" id="_ref_6961"><a href="syntax-directed-operations.html#sec-static-semantics-isconstantdeclaration">IsConstantDeclaration</a></emu-xref> of <var>d</var> is <emu-val>true</emu-val>, then<ol><li>Perform !&nbsp;<var>env</var>.<emu-xref aoid="CreateImmutableBinding" id="_ref_6962"><a href="executable-code-and-execution-contexts.html#abstract-createimmutablebinding">CreateImmutableBinding</a></emu-xref>(<var>dn</var>, <emu-val>true</emu-val>).</li></ol></li><li>Else,<ol><li id="step-blockdeclarationinstantiation-createmutablebinding" normative-optional=""><div class="attributes-tag"><emu-xref href="#sec-conformance" id="_ref_6956"><a href="conformance.html#sec-conformance">Normative Optional</a></emu-xref></div>If the <emu-xref href="#host" id="_ref_6963"><a href="overview.html#host">host</a></emu-xref> is a web browser or otherwise supports <emu-xref href="#sec-block-level-function-declarations-web-legacy-compatibility-semantics" title="" id="_ref_441"><a href="additional-ecmascript-features-for-web-browsers.html#sec-block-level-function-declarations-web-legacy-compatibility-semantics">Block-Level Function Declarations Web Legacy Compatibility Semantics</a></emu-xref>, then<ol><li>If !&nbsp;<var>env</var>.<emu-xref aoid="HasBinding" id="_ref_6964"><a href="executable-code-and-execution-contexts.html#abstract-hasbinding">HasBinding</a></emu-xref>(<var>dn</var>) is <emu-val>false</emu-val>, then<ol><li>Perform !&nbsp;<var>env</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_6965"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>dn</var>, <emu-val>false</emu-val>).</li></ol></li></ol></li><li>Else,<ol><li>Perform !&nbsp;<var>env</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_6966"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>dn</var>, <emu-val>false</emu-val>).</li></ol></li></ol></li></ol></li><li>If <var>d</var> is either a <emu-nt id="_ref_21455"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt>, a <emu-nt id="_ref_21456"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorDeclaration">GeneratorDeclaration</a></emu-nt>, an <emu-nt id="_ref_21457"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncFunctionDeclaration">AsyncFunctionDeclaration</a></emu-nt>, or an <emu-nt id="_ref_21458"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorDeclaration">AsyncGeneratorDeclaration</a></emu-nt>, then<ol><li>Let <var>fn</var> be the sole element of the <emu-xref aoid="BoundNames" id="_ref_6967"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <var>d</var>.</li><li>Let <var>fo</var> be <emu-xref aoid="InstantiateFunctionObject" id="_ref_6968"><a href="syntax-directed-operations.html#sec-runtime-semantics-instantiatefunctionobject">InstantiateFunctionObject</a></emu-xref> of <var>d</var> with arguments <var>env</var> and <var>privateEnv</var>.</li><li id="step-blockdeclarationinstantiation-initializebinding" normative-optional=""><div class="attributes-tag"><emu-xref href="#sec-conformance" id="_ref_6957"><a href="conformance.html#sec-conformance">Normative Optional</a></emu-xref></div>If the <emu-xref href="#host" id="_ref_6969"><a href="overview.html#host">host</a></emu-xref> is a web browser or otherwise supports <emu-xref href="#sec-block-level-function-declarations-web-legacy-compatibility-semantics" title="" id="_ref_442"><a href="additional-ecmascript-features-for-web-browsers.html#sec-block-level-function-declarations-web-legacy-compatibility-semantics">Block-Level Function Declarations Web Legacy Compatibility Semantics</a></emu-xref>, then<ol><li>If the binding for <var>fn</var> in <var>env</var> is an uninitialized binding, then<ol><li>Perform !&nbsp;<var>env</var>.<emu-xref aoid="InitializeBinding" id="_ref_6970"><a href="executable-code-and-execution-contexts.html#abstract-initializebinding">InitializeBinding</a></emu-xref>(<var>fn</var>, <var>fo</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_6971"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>d</var> is a <emu-nt id="_ref_21459"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt>.</li><li>Perform !&nbsp;<var>env</var>.<emu-xref aoid="SetMutableBinding" id="_ref_6972"><a href="executable-code-and-execution-contexts.html#abstract-setmutablebinding">SetMutableBinding</a></emu-xref>(<var>fn</var>, <var>fo</var>, <emu-val>false</emu-val>).</li></ol></li></ol></li><li>Else,<ol><li>Perform !&nbsp;<var>env</var>.<emu-xref aoid="InitializeBinding" id="_ref_6973"><a href="executable-code-and-execution-contexts.html#abstract-initializebinding">InitializeBinding</a></emu-xref>(<var>fn</var>, <var>fo</var>).</li></ol></li></ol></li></ol></li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-declarations-and-the-variable-statement">
<h1><span class="secnum">14.3</span> Declarations and the Variable Statement</h1>
<emu-clause id="sec-let-and-const-declarations">
<h1><span class="secnum">14.3.1</span> Let and Const Declarations</h1>
<emu-note><span class="note">Note</span><div class="note-contents">
<p><code>let</code> and <code>const</code> declarations define variables that are scoped to the <emu-xref href="#running-execution-context" id="_ref_6974"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment. The variables are created when their containing <emu-xref href="#sec-environment-records" id="_ref_6975"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> is instantiated but may not be accessed in any way until the variable's <emu-nt id="_ref_21460"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> is evaluated. A variable defined by a <emu-nt id="_ref_21461"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> with an <emu-nt id="_ref_21462"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> is assigned the value of its <emu-nt id="_ref_21463"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>'s <emu-nt id="_ref_21464"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt> when the <emu-nt id="_ref_21465"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> is evaluated, not when the variable is created. If a <emu-nt id="_ref_21466"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> in a <code>let</code> declaration does not have an <emu-nt id="_ref_21467"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> the variable is assigned the value <emu-val>undefined</emu-val> when the <emu-nt id="_ref_21468"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> is evaluated.</p>
</div></emu-note>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="LexicalDeclaration" params="In, Yield, Await" id="prod-LexicalDeclaration">
<emu-nt params="In, Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a><emu-mods><emu-params>[In, Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jsmbgalx" id="prod-10DUWE8d">
<emu-nt id="_ref_21469"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21470"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="LetOrConst" id="prod-LetOrConst">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="laxrvawy" id="prod-7oqY0VPN">
<emu-t>let</emu-t>
</emu-rhs>
<emu-rhs a="nim_d4hb" id="prod-rTRI6GVQ">
<emu-t>const</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="BindingList" params="In, Yield, Await" id="prod-BindingList">
<emu-nt params="In, Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a><emu-mods><emu-params>[In, Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ned6hkwu">
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21471"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="fdx7nvya" id="prod-FYQ2Ly4e">
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21472"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>,</emu-t>
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21473"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="LexicalBinding" params="In, Yield, Await" id="prod-LexicalBinding">
<emu-nt params="In, Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a><emu-mods><emu-params>[In, Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jut8etgz" id="prod-l3Hg2UJ0">
<emu-nt params="?Yield, ?Await" id="_ref_21474"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="?In, ?Yield, ?Await" optional="" id="_ref_21475"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="sdckvxer" id="prod-FppJpMK8">
<emu-nt params="?Yield, ?Await" id="_ref_21476"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21477"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-let-and-const-declarations-static-semantics-early-errors">
<h1><span class="secnum">14.3.1.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="LexicalDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="deqecbrp">
<emu-nt id="_ref_21478"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt id="_ref_21479"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if the <emu-xref aoid="BoundNames" id="_ref_6976"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21480"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt> contains <emu-val>"let"</emu-val>.
</li>
<li>
It is a Syntax Error if the <emu-xref aoid="BoundNames" id="_ref_6977"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21481"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt> contains any duplicate entries.
</li>
</ul>
<emu-grammar><emu-production name="LexicalBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="c5neqctp">
<emu-nt id="_ref_21482"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>
<emu-nt optional="" id="_ref_21483"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-nt id="_ref_21484"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> is not present and <emu-xref aoid="IsConstantDeclaration" id="_ref_6978"><a href="syntax-directed-operations.html#sec-static-semantics-isconstantdeclaration">IsConstantDeclaration</a></emu-xref> of the <emu-nt id="_ref_21485"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt> containing this <emu-nt id="_ref_21486"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> is <emu-val>true</emu-val>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-let-and-const-declarations-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.3.1.2</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="LexicalDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="deqecbrp" id="prod-dx4AGe8K">
<emu-nt id="_ref_21487"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt id="_ref_21488"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6979"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21489"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt>.</li><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="BindingList" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="dt40zeyt" id="prod-EyFo2V-D">
<emu-nt id="_ref_21490"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt>
<emu-t>,</emu-t>
<emu-nt id="_ref_21491"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6980"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21492"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingList">BindingList</a></emu-nt>.</li><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6981"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21493"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt>.</li></ol></emu-alg>
<emu-grammar><emu-production name="LexicalBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uolyom43" id="prod-mW_TWZBz"><emu-nt id="_ref_21494"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>lhs</var> be !&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_6982"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding">ResolveBinding</a></emu-xref>(<emu-xref aoid="StringValue" id="_ref_6983"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21495"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>).</li><li>Perform !&nbsp;<emu-xref aoid="InitializeReferencedBinding" id="_ref_6984"><a href="ecmascript-data-types-and-values.html#sec-initializereferencedbinding">InitializeReferencedBinding</a></emu-xref>(<var>lhs</var>, <emu-val>undefined</emu-val>).</li><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>A <emu-xref href="#sec-static-semantic-rules" id="_ref_6985"><a href="notational-conventions.html#sec-static-semantic-rules">static semantics</a></emu-xref> rule ensures that this form of <emu-nt id="_ref_21496"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> never occurs in a <code>const</code> declaration.</p>
</div></emu-note>
<emu-grammar><emu-production name="LexicalBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ib7lg1vi" id="prod-gOqjOKq_">
<emu-nt id="_ref_21497"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>
<emu-nt id="_ref_21498"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>bindingId</var> be the <emu-xref aoid="StringValue" id="_ref_6986"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21499"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>.</li><li>Let <var>lhs</var> be !&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_6987"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding">ResolveBinding</a></emu-xref>(<var>bindingId</var>).</li><li>If <emu-xref aoid="IsAnonymousFunctionDefinition" id="_ref_6988"><a href="syntax-directed-operations.html#sec-isanonymousfunctiondefinition">IsAnonymousFunctionDefinition</a></emu-xref>(<emu-nt id="_ref_21500"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>) is <emu-val>true</emu-val>, then<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="NamedEvaluation" id="_ref_6989"><a href="syntax-directed-operations.html#sec-runtime-semantics-namedevaluation" class="e-user-code">NamedEvaluation</a></emu-xref> of <emu-nt id="_ref_21501"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> with argument <var>bindingId</var>.</li></ol></li><li>Else,<ol><li>Let <var>rhs</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6990"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21502"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>.</li><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_6991"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>rhs</var>).</li></ol></li><li>Perform !&nbsp;<emu-xref aoid="InitializeReferencedBinding" id="_ref_6992"><a href="ecmascript-data-types-and-values.html#sec-initializereferencedbinding">InitializeReferencedBinding</a></emu-xref>(<var>lhs</var>, <var>value</var>).</li><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="LexicalBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="dd1t5ekf" id="prod-HJPtX-Q7">
<emu-nt id="_ref_21503"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt>
<emu-nt id="_ref_21504"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>rhs</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6993"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21505"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>.</li><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_6994"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>rhs</var>).</li><li>Let <var>env</var> be the <emu-xref href="#running-execution-context" id="_ref_6995"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Return ?&nbsp;<emu-xref aoid="BindingInitialization" id="_ref_6996"><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" class="e-user-code">BindingInitialization</a></emu-xref> of <emu-nt id="_ref_21506"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt> with arguments <var>value</var> and <var>env</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-variable-statement">
<h1><span class="secnum">14.3.2</span> Variable Statement</h1>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>A <code>var</code> statement declares variables that are scoped to the <emu-xref href="#running-execution-context" id="_ref_6997"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s VariableEnvironment. Var variables are created when their containing <emu-xref href="#sec-environment-records" id="_ref_6998"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> is instantiated and are initialized to <emu-val>undefined</emu-val> when created. Within the scope of any VariableEnvironment a common <emu-nt id="_ref_21507"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt> may appear in more than one <emu-nt id="_ref_21508"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> but those declarations collectively define only one variable. A variable defined by a <emu-nt id="_ref_21509"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> with an <emu-nt id="_ref_21510"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> is assigned the value of its <emu-nt id="_ref_21511"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>'s <emu-nt id="_ref_21512"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt> when the <emu-nt id="_ref_21513"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> is executed, not when the variable is created.</p>
</div></emu-note>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="VariableStatement" params="Yield, Await" id="prod-VariableStatement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableStatement">VariableStatement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="tbwjaldb" id="prod-03w8p9mr">
<emu-t>var</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21514"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="VariableDeclarationList" params="In, Yield, Await" id="prod-VariableDeclarationList">
<emu-nt params="In, Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a><emu-mods><emu-params>[In, Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ps4sw3ys" id="prod-bXRN6REu">
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21515"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="xsh3skws" id="prod-kqbqpKlK">
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21516"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>,</emu-t>
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21517"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="VariableDeclaration" params="In, Yield, Await" id="prod-VariableDeclaration">
<emu-nt params="In, Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a><emu-mods><emu-params>[In, Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jut8etgz" id="prod-IeHby7A3">
<emu-nt params="?Yield, ?Await" id="_ref_21518"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="?In, ?Yield, ?Await" optional="" id="_ref_21519"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="sdckvxer" id="prod-MhsdViui">
<emu-nt params="?Yield, ?Await" id="_ref_21520"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="?In, ?Yield, ?Await" id="_ref_21521"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-params>[?In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-variable-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.3.2.1</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="VariableStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-VariableStatement">VariableStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="m0ehvb8m" id="prod-3b9-3HdT">
<emu-t>var</emu-t>
<emu-nt id="_ref_21522"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_6999"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21523"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>.</li><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="VariableDeclarationList" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="oavweevb" id="prod-mRNvbUb_">
<emu-nt id="_ref_21524"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>
<emu-t>,</emu-t>
<emu-nt id="_ref_21525"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7000"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21526"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>.</li><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7001"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21527"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt>.</li></ol></emu-alg>
<emu-grammar><emu-production name="VariableDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uolyom43" id="prod-DloKhDSp"><emu-nt id="_ref_21528"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="VariableDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ib7lg1vi" id="prod-luUzRvcA">
<emu-nt id="_ref_21529"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>
<emu-nt id="_ref_21530"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>bindingId</var> be the <emu-xref aoid="StringValue" id="_ref_7002"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21531"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>.</li><li>Let <var>lhs</var> be ?&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_7003"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding" class="e-user-code">ResolveBinding</a></emu-xref>(<var>bindingId</var>).</li><li>If <emu-xref aoid="IsAnonymousFunctionDefinition" id="_ref_7004"><a href="syntax-directed-operations.html#sec-isanonymousfunctiondefinition">IsAnonymousFunctionDefinition</a></emu-xref>(<emu-nt id="_ref_21532"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>) is <emu-val>true</emu-val>, then<ol><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="NamedEvaluation" id="_ref_7005"><a href="syntax-directed-operations.html#sec-runtime-semantics-namedevaluation" class="e-user-code">NamedEvaluation</a></emu-xref> of <emu-nt id="_ref_21533"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> with argument <var>bindingId</var>.</li></ol></li><li>Else,<ol><li>Let <var>rhs</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7006"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21534"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>.</li><li>Let <var>value</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7007"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>rhs</var>).</li></ol></li><li id="step-vardecllist-evaluation-putvalue">Perform ?&nbsp;<emu-xref aoid="PutValue" id="_ref_7008"><a href="ecmascript-data-types-and-values.html#sec-putvalue" class="e-user-code">PutValue</a></emu-xref>(<var>lhs</var>, <var>value</var>).</li><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>If a <emu-nt id="_ref_21535"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> is nested within a with statement and the <emu-nt id="_ref_21536"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt> in the <emu-nt id="_ref_21537"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> is the same as a <emu-xref href="#property-name" id="_ref_7009"><a href="ecmascript-data-types-and-values.html#property-name">property name</a></emu-xref> of the binding object of the with statement's <emu-xref href="#sec-object-environment-records" id="_ref_7010"><a href="executable-code-and-execution-contexts.html#sec-object-environment-records">Object Environment Record</a></emu-xref>, then step <emu-xref href="#step-vardecllist-evaluation-putvalue" id="_ref_443"><a href="ecmascript-language-statements-and-declarations.html#step-vardecllist-evaluation-putvalue">5</a></emu-xref> will assign <var>value</var> to the property instead of assigning to the VariableEnvironment binding of the <emu-nt id="_ref_21538"><a href="ecmascript-language-expressions.html#prod-Identifier">Identifier</a></emu-nt>.</p>
</div></emu-note>
<emu-grammar><emu-production name="VariableDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclaration">VariableDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="dd1t5ekf" id="prod-615TDHeB">
<emu-nt id="_ref_21539"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt>
<emu-nt id="_ref_21540"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>rhs</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7011"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21541"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>.</li><li>Let <var>rVal</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7012"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>rhs</var>).</li><li>Return ?&nbsp;<emu-xref aoid="BindingInitialization" id="_ref_7013"><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" class="e-user-code">BindingInitialization</a></emu-xref> of <emu-nt id="_ref_21542"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt> with arguments <var>rVal</var> and <emu-val>undefined</emu-val>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-destructuring-binding-patterns">
<h1><span class="secnum">14.3.3</span> Destructuring Binding Patterns</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="BindingPattern" params="Yield, Await" id="prod-BindingPattern">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="fwd2jmee" id="prod-5GwwFymY">
<emu-nt params="?Yield, ?Await" id="_ref_21543"><a href="ecmascript-language-statements-and-declarations.html#prod-ObjectBindingPattern">ObjectBindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="hpyn1kot" id="prod-nQ2ZFnUa">
<emu-nt params="?Yield, ?Await" id="_ref_21544"><a href="ecmascript-language-statements-and-declarations.html#prod-ArrayBindingPattern">ArrayBindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="ObjectBindingPattern" params="Yield, Await" id="prod-ObjectBindingPattern">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ObjectBindingPattern">ObjectBindingPattern</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gbpaspne" id="prod-Zq1KBCx2">
<emu-t>{</emu-t>
<emu-t>}</emu-t>
</emu-rhs>
<emu-rhs a="u51ece_j" id="prod-5lmgiaFr">
<emu-t>{</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21545"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestProperty">BindingRestProperty</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
<emu-rhs a="sd_sxlxl" id="prod-xrMoI6uo">
<emu-t>{</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21546"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
<emu-rhs a="98sthfnw" id="prod-ZImPf3XQ">
<emu-t>{</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21547"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>,</emu-t>
<emu-nt params="?Yield, ?Await" optional="" id="_ref_21548"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestProperty">BindingRestProperty</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="ArrayBindingPattern" params="Yield, Await" id="prod-ArrayBindingPattern">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ArrayBindingPattern">ArrayBindingPattern</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="82yazf9m" id="prod-GTLtfjt0">
<emu-t>[</emu-t>
<emu-nt optional="" id="_ref_21549"><a href="ecmascript-language-expressions.html#prod-Elision">Elision</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await" optional="" id="_ref_21550"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestElement">BindingRestElement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>]</emu-t>
</emu-rhs>
<emu-rhs a="tz2jlcig">
<emu-t>[</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21551"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElementList">BindingElementList</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>]</emu-t>
</emu-rhs>
<emu-rhs a="ezfh7oge" id="prod-ZEEMEcAo">
<emu-t>[</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21552"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElementList">BindingElementList</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>,</emu-t>
<emu-nt optional="" id="_ref_21553"><a href="ecmascript-language-expressions.html#prod-Elision">Elision</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await" optional="" id="_ref_21554"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestElement">BindingRestElement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>]</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="BindingRestProperty" params="Yield, Await" id="prod-BindingRestProperty">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestProperty">BindingRestProperty</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="nldxez3v" id="prod-ltwW708a">
<emu-t>...</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21555"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BindingPropertyList" params="Yield, Await" id="prod-BindingPropertyList">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="8baidhkc">
<emu-nt params="?Yield, ?Await" id="_ref_21556"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="ewlfehxq" id="prod-TkJ_upuv">
<emu-nt params="?Yield, ?Await" id="_ref_21557"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>,</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21558"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BindingElementList" params="Yield, Await" id="prod-BindingElementList">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElementList">BindingElementList</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="lpaw4nny">
<emu-nt params="?Yield, ?Await" id="_ref_21559"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElisionElement">BindingElisionElement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="5z8zw101" id="prod-QAGJVJ9v">
<emu-nt params="?Yield, ?Await" id="_ref_21560"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElementList">BindingElementList</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>,</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21561"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElisionElement">BindingElisionElement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BindingElisionElement" params="Yield, Await" id="prod-BindingElisionElement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElisionElement">BindingElisionElement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="5jbcqvdg" id="prod-eAKFkNTn">
<emu-nt optional="" id="_ref_21562"><a href="ecmascript-language-expressions.html#prod-Elision">Elision</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await" id="_ref_21563"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElement">BindingElement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BindingProperty" params="Yield, Await" id="prod-BindingProperty">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="01jnavb_" id="prod-P9s8hLuP">
<emu-nt params="?Yield, ?Await" id="_ref_21564"><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="xcksc8qh" id="prod-VmvTFDAY">
<emu-nt params="?Yield, ?Await" id="_ref_21565"><a href="ecmascript-language-expressions.html#prod-PropertyName">PropertyName</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>:</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21566"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElement">BindingElement</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BindingElement" params="Yield, Await" id="prod-BindingElement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElement">BindingElement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="01jnavb_">
<emu-nt params="?Yield, ?Await" id="_ref_21567"><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="eyv5t9mz" id="prod-qY39_uPQ">
<emu-nt params="?Yield, ?Await" id="_ref_21568"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21569"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="SingleNameBinding" params="Yield, Await" id="prod-SingleNameBinding">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="mg7mmvow" id="prod-8lbkfoVZ">
<emu-nt params="?Yield, ?Await" id="_ref_21570"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21571"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="BindingRestElement" params="Yield, Await" id="prod-BindingRestElement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestElement">BindingRestElement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="nldxez3v" id="prod-0fOwNHr-">
<emu-t>...</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21572"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="lb7grnzq" id="prod-iBHkClE5">
<emu-t>...</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21573"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-destructuring-binding-patterns-runtime-semantics-propertybindinginitialization" type="sdo" aoid="PropertyBindingInitialization">
<h1><span class="secnum">14.3.3.1</span> Runtime Semantics: PropertyBindingInitialization</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7014"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> PropertyBindingInitialization takes arguments <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7015"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and <var>environment</var> (an <emu-xref href="#sec-environment-records" id="_ref_7016"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> or <emu-val>undefined</emu-val>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7017"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7018"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-xref href="#property-key" id="_ref_7019"><a href="ecmascript-data-types-and-values.html#property-key">property keys</a></emu-xref> or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7020"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It collects a list of all bound <emu-xref href="#property-name" id="_ref_7021"><a href="ecmascript-data-types-and-values.html#property-name">property names</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="BindingPropertyList" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="bzdeo9zt" id="prod-jhtKd-Y5">
<emu-nt id="_ref_21574"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a></emu-nt>
<emu-t>,</emu-t>
<emu-nt id="_ref_21575"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>boundNames</var> be ?&nbsp;<emu-xref aoid="PropertyBindingInitialization" id="_ref_7022"><a href="ecmascript-language-statements-and-declarations.html#sec-destructuring-binding-patterns-runtime-semantics-propertybindinginitialization" class="e-user-code">PropertyBindingInitialization</a></emu-xref> of <emu-nt id="_ref_21576"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPropertyList">BindingPropertyList</a></emu-nt> with arguments <var>value</var> and <var>environment</var>.</li><li>Let <var>nextNames</var> be ?&nbsp;<emu-xref aoid="PropertyBindingInitialization" id="_ref_7023"><a href="ecmascript-language-statements-and-declarations.html#sec-destructuring-binding-patterns-runtime-semantics-propertybindinginitialization" class="e-user-code">PropertyBindingInitialization</a></emu-xref> of <emu-nt id="_ref_21577"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a></emu-nt> with arguments <var>value</var> and <var>environment</var>.</li><li>Return the <emu-xref href="#list-concatenation" id="_ref_7024"><a href="ecmascript-data-types-and-values.html#list-concatenation">list-concatenation</a></emu-xref> of <var>boundNames</var> and <var>nextNames</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="BindingProperty" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="lof8ala-" id="prod--5EhKk0m"><emu-nt id="_ref_21578"><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>name</var> be the sole element of the <emu-xref aoid="BoundNames" id="_ref_7025"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21579"><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a></emu-nt>.</li><li>Perform ?&nbsp;<emu-xref aoid="KeyedBindingInitialization" id="_ref_7026"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-keyedbindinginitialization" class="e-user-code">KeyedBindingInitialization</a></emu-xref> of <emu-nt id="_ref_21580"><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a></emu-nt> with arguments <var>value</var>, <var>environment</var>, and <var>name</var>.</li><li>Return « <var>name</var>&nbsp;».</li></ol></emu-alg>
<emu-grammar><emu-production name="BindingProperty" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BindingProperty">BindingProperty</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="mhvrwluk" id="prod-1euONYQ-">
<emu-nt id="_ref_21581"><a href="ecmascript-language-expressions.html#prod-PropertyName">PropertyName</a></emu-nt>
<emu-t>:</emu-t>
<emu-nt id="_ref_21582"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElement">BindingElement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>P</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7027"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21583"><a href="ecmascript-language-expressions.html#prod-PropertyName">PropertyName</a></emu-nt>.</li><li>Perform ?&nbsp;<emu-xref aoid="KeyedBindingInitialization" id="_ref_7028"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-keyedbindinginitialization" class="e-user-code">KeyedBindingInitialization</a></emu-xref> of <emu-nt id="_ref_21584"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElement">BindingElement</a></emu-nt> with arguments <var>value</var>, <var>environment</var>, and <var>P</var>.</li><li>Return « <var>P</var>&nbsp;».</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-destructuring-binding-patterns-runtime-semantics-restbindinginitialization" type="sdo" aoid="RestBindingInitialization">
<h1><span class="secnum">14.3.3.2</span> Runtime Semantics: RestBindingInitialization</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7029"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> RestBindingInitialization takes arguments <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7030"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>), <var>environment</var> (an <emu-xref href="#sec-environment-records" id="_ref_7031"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> or <emu-val>undefined</emu-val>), and <var>excludedNames</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7032"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-xref href="#property-key" id="_ref_7033"><a href="ecmascript-data-types-and-values.html#property-key">property keys</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7034"><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 an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7035"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="BindingRestProperty" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BindingRestProperty">BindingRestProperty</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ffhe3nqa" id="prod-jjw6mbi6">
<emu-t>...</emu-t>
<emu-nt id="_ref_21585"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>lhs</var> be ?&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_7036"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding" class="e-user-code">ResolveBinding</a></emu-xref>(<emu-xref aoid="StringValue" id="_ref_7037"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21586"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>, <var>environment</var>).</li><li>Let <var>restObj</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_7038"><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_7039"><a href="fundamental-objects.html#sec-properties-of-the-object-prototype-object">%Object.prototype%</a></emu-xref>).</li><li>Perform ?&nbsp;<emu-xref aoid="CopyDataProperties" id="_ref_7040"><a href="abstract-operations.html#sec-copydataproperties" class="e-user-code">CopyDataProperties</a></emu-xref>(<var>restObj</var>, <var>value</var>, <var>excludedNames</var>).</li><li>If <var>environment</var> is <emu-val>undefined</emu-val>, return ?&nbsp;<emu-xref aoid="PutValue" id="_ref_7041"><a href="ecmascript-data-types-and-values.html#sec-putvalue" class="e-user-code">PutValue</a></emu-xref>(<var>lhs</var>, <var>restObj</var>).</li><li>Return ?&nbsp;<emu-xref aoid="InitializeReferencedBinding" id="_ref_7042"><a href="ecmascript-data-types-and-values.html#sec-initializereferencedbinding">InitializeReferencedBinding</a></emu-xref>(<var>lhs</var>, <var>restObj</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-runtime-semantics-keyedbindinginitialization" type="sdo" aoid="KeyedBindingInitialization">
<h1><span class="secnum">14.3.3.3</span> Runtime Semantics: KeyedBindingInitialization</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7043"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> KeyedBindingInitialization takes arguments <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7044"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>), <var>environment</var> (an <emu-xref href="#sec-environment-records" id="_ref_7045"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> or <emu-val>undefined</emu-val>), and <var>propertyName</var> (a <emu-xref href="#property-key" id="_ref_7046"><a href="ecmascript-data-types-and-values.html#property-key">property key</a></emu-xref>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7047"><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 an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7048"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>.</p>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>When <emu-val>undefined</emu-val> is passed for <var>environment</var> it indicates that a <emu-xref aoid="PutValue" id="_ref_7049"><a href="ecmascript-data-types-and-values.html#sec-putvalue">PutValue</a></emu-xref> operation should be used to assign the initialization value. This is the case for formal parameter lists of <emu-xref href="#non-strict-function" id="_ref_7050"><a href="ordinary-and-exotic-objects-behaviours.html#non-strict-function">non-strict functions</a></emu-xref>. In that case the formal parameter bindings are preinitialized in order to deal with the possibility of multiple parameters with the same name.</p>
</div></emu-note>
<p>It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="BindingElement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BindingElement">BindingElement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ahx6lm0w" id="prod-kKvAd4Kx">
<emu-nt id="_ref_21587"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt>
<emu-nt optional="" id="_ref_21588"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>v</var> be ?&nbsp;<emu-xref aoid="GetV" id="_ref_7051"><a href="abstract-operations.html#sec-getv" class="e-user-code">GetV</a></emu-xref>(<var>value</var>, <var>propertyName</var>).</li><li>If <emu-nt id="_ref_21589"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> is present and <var>v</var> is <emu-val>undefined</emu-val>, then<ol><li>Let <var>defaultValue</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7052"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21590"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>.</li><li>Set <var>v</var> to ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7053"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>defaultValue</var>).</li></ol></li><li>Return ?&nbsp;<emu-xref aoid="BindingInitialization" id="_ref_7054"><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" class="e-user-code">BindingInitialization</a></emu-xref> of <emu-nt id="_ref_21591"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt> with arguments <var>v</var> and <var>environment</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="SingleNameBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-SingleNameBinding">SingleNameBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="c5neqctp" id="prod-v4J727kL">
<emu-nt id="_ref_21592"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>
<emu-nt optional="" id="_ref_21593"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>bindingId</var> be the <emu-xref aoid="StringValue" id="_ref_7055"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21594"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>.</li><li>Let <var>lhs</var> be ?&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_7056"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding" class="e-user-code">ResolveBinding</a></emu-xref>(<var>bindingId</var>, <var>environment</var>).</li><li>Let <var>v</var> be ?&nbsp;<emu-xref aoid="GetV" id="_ref_7057"><a href="abstract-operations.html#sec-getv" class="e-user-code">GetV</a></emu-xref>(<var>value</var>, <var>propertyName</var>).</li><li>If <emu-nt id="_ref_21595"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> is present and <var>v</var> is <emu-val>undefined</emu-val>, then<ol><li>If <emu-xref aoid="IsAnonymousFunctionDefinition" id="_ref_7058"><a href="syntax-directed-operations.html#sec-isanonymousfunctiondefinition">IsAnonymousFunctionDefinition</a></emu-xref>(<emu-nt id="_ref_21596"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>) is <emu-val>true</emu-val>, then<ol><li>Set <var>v</var> to ?&nbsp;<emu-xref aoid="NamedEvaluation" id="_ref_7059"><a href="syntax-directed-operations.html#sec-runtime-semantics-namedevaluation" class="e-user-code">NamedEvaluation</a></emu-xref> of <emu-nt id="_ref_21597"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt> with argument <var>bindingId</var>.</li></ol></li><li>Else,<ol><li>Let <var>defaultValue</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7060"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21598"><a href="ecmascript-language-expressions.html#prod-Initializer">Initializer</a></emu-nt>.</li><li>Set <var>v</var> to ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7061"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>defaultValue</var>).</li></ol></li></ol></li><li>If <var>environment</var> is <emu-val>undefined</emu-val>, return ?&nbsp;<emu-xref aoid="PutValue" id="_ref_7062"><a href="ecmascript-data-types-and-values.html#sec-putvalue" class="e-user-code">PutValue</a></emu-xref>(<var>lhs</var>, <var>v</var>).</li><li>Return ?&nbsp;<emu-xref aoid="InitializeReferencedBinding" id="_ref_7063"><a href="ecmascript-data-types-and-values.html#sec-initializereferencedbinding">InitializeReferencedBinding</a></emu-xref>(<var>lhs</var>, <var>v</var>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-empty-statement">
<h1><span class="secnum">14.4</span> Empty Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="EmptyStatement" id="prod-EmptyStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-EmptyStatement">EmptyStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="sg2sawim" id="prod-hl28S5p6">
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-empty-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.4.1</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="EmptyStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-EmptyStatement">EmptyStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="sg2sawim" id="prod-il1Ue5QP"><emu-t>;</emu-t></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-expression-statement">
<h1><span class="secnum">14.5</span> Expression Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="ExpressionStatement" params="Yield, Await" id="prod-ExpressionStatement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="nmo0iroq" id="prod-XGPiPhtM">
<emu-gann>[lookahead ∉ { <emu-t>{</emu-t>, <emu-t>function</emu-t>, <emu-t>async</emu-t>
<emu-gann>[no <emu-nt id="_ref_21599"><a href="ecmascript-language-lexical-grammar.html#prod-LineTerminator">LineTerminator</a></emu-nt> here]</emu-gann>
<emu-t>function</emu-t>, <emu-t>class</emu-t>, <emu-t>let</emu-t>
<emu-t>[</emu-t> }]</emu-gann>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21600"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>An <emu-nt id="_ref_21601"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a></emu-nt> cannot start with a U+007B (LEFT CURLY BRACKET) because that might make it ambiguous with a <emu-nt id="_ref_21602"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>. An <emu-nt id="_ref_21603"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a></emu-nt> cannot start with the <code>function</code> or <code>class</code> <emu-xref href="#sec-keywords-and-reserved-words" id="_ref_7064"><a href="ecmascript-language-lexical-grammar.html#sec-keywords-and-reserved-words">keywords</a></emu-xref> because that would make it ambiguous with a <emu-nt id="_ref_21604"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt>, a <emu-nt id="_ref_21605"><a href="ecmascript-language-functions-and-classes.html#prod-GeneratorDeclaration">GeneratorDeclaration</a></emu-nt>, or a <emu-nt id="_ref_21606"><a href="ecmascript-language-functions-and-classes.html#prod-ClassDeclaration">ClassDeclaration</a></emu-nt>. An <emu-nt id="_ref_21607"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a></emu-nt> cannot start with <code>async function</code> because that would make it ambiguous with an <emu-nt id="_ref_21608"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncFunctionDeclaration">AsyncFunctionDeclaration</a></emu-nt> or a <emu-nt id="_ref_21609"><a href="ecmascript-language-functions-and-classes.html#prod-AsyncGeneratorDeclaration">AsyncGeneratorDeclaration</a></emu-nt>. An <emu-nt id="_ref_21610"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a></emu-nt> cannot start with the two token sequence <code>let [</code> because that would make it ambiguous with a <code>let</code> <emu-nt id="_ref_21611"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt> whose first <emu-nt id="_ref_21612"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalBinding">LexicalBinding</a></emu-nt> was an <emu-nt id="_ref_21613"><a href="ecmascript-language-statements-and-declarations.html#prod-ArrayBindingPattern">ArrayBindingPattern</a></emu-nt>.</p>
</div></emu-note>
<emu-clause id="sec-expression-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.5.1</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="ExpressionStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="4ttdnuln" id="prod-zmcsioZW">
<emu-nt id="_ref_21614"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7065"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21615"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Return ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7066"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-if-statement">
<h1><span class="secnum">14.6</span> The <code>if</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="IfStatement" params="Yield, Await, Return" id="prod-IfStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gvkksvw-" id="prod-_lf1EvXT">
<emu-t>if</emu-t>
<emu-t>(</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21616"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21617"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-t>else</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21618"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="x9p_cd-n" id="prod--e2u-nCd">
<emu-t>if</emu-t>
<emu-t>(</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21619"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21620"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-gann>[lookahead ≠ <emu-t>else</emu-t>]</emu-gann>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note</span><div class="note-contents">The lookahead-restriction [lookahead ≠ <code>else</code>] resolves the classic "dangling else" problem in the usual way. That is, when the choice of associated <code>if</code> is otherwise ambiguous, the <code>else</code> is associated with the nearest (innermost) of the candidate <code>if</code>s</div></emu-note>
<emu-clause id="sec-if-statement-static-semantics-early-errors">
<h1><span class="secnum">14.6.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="IfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="fuhqe2xq">
<emu-t>if</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21621"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21622"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
<emu-t>else</emu-t>
<emu-nt id="_ref_21623"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7067"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(the first <emu-nt id="_ref_21624"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7068"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(the second <emu-nt id="_ref_21625"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-grammar><emu-production name="IfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="9ogvciaf">
<emu-t>if</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21626"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21627"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7069"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<emu-nt id="_ref_21628"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>It is only necessary to apply this rule if the extension specified in <emu-xref href="#sec-labelled-function-declarations" id="_ref_444"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">B.3.1</a></emu-xref> is implemented.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-if-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.6.2</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="IfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="fuhqe2xq" id="prod-V-mFBCSX">
<emu-t>if</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21629"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21630"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
<emu-t>else</emu-t>
<emu-nt id="_ref_21631"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7070"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21632"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>exprValue</var> be <emu-xref aoid="ToBoolean" id="_ref_7071"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(? <emu-xref aoid="GetValue" id="_ref_7072"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>)).</li><li>If <var>exprValue</var> is <emu-val>true</emu-val>, then<ol><li>Let <var>stmtCompletion</var> be <emu-xref aoid="Completion" id="_ref_7073"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7074"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of the first <emu-nt id="_ref_21633"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>).</li></ol></li><li>Else,<ol><li>Let <var>stmtCompletion</var> be <emu-xref aoid="Completion" id="_ref_7075"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7076"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of the second <emu-nt id="_ref_21634"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>).</li></ol></li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7077"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>stmtCompletion</var>, <emu-val>undefined</emu-val>).</li></ol></emu-alg>
<emu-grammar><emu-production name="IfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="9ogvciaf" id="prod-31mgDA5h">
<emu-t>if</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21635"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21636"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7078"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21637"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>exprValue</var> be <emu-xref aoid="ToBoolean" id="_ref_7079"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(? <emu-xref aoid="GetValue" id="_ref_7080"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>)).</li><li>If <var>exprValue</var> is <emu-val>false</emu-val>, return <emu-val>undefined</emu-val>.</li><li>Let <var>stmtCompletion</var> be <emu-xref aoid="Completion" id="_ref_7081"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7082"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21638"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>).</li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7083"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>stmtCompletion</var>, <emu-val>undefined</emu-val>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-iteration-statements">
<h1><span class="secnum">14.7</span> Iteration Statements</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="IterationStatement" params="Yield, Await, Return" id="prod-IterationStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="cfhtf2jt" id="prod-nthWw5bM">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21639"><a href="ecmascript-language-statements-and-declarations.html#prod-DoWhileStatement">DoWhileStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="v6obhs7z" id="prod-J0YbLQ2x">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21640"><a href="ecmascript-language-statements-and-declarations.html#prod-WhileStatement">WhileStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="cito49hq" id="prod-r-Sjm4F3">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21641"><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="ysjy7ne3" id="prod-Q0CapowH">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21642"><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-iteration-statements-semantics">
<h1><span class="secnum">14.7.1</span> Semantics</h1>
<emu-clause id="sec-loopcontinues" type="abstract operation" aoid="LoopContinues">
<h1><span class="secnum">14.7.1.1</span> LoopContinues ( <var>completion</var>, <var>labelSet</var> )</h1>
<p>The abstract operation LoopContinues takes arguments <var>completion</var> (a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7084"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>) and <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7085"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns a Boolean. It performs the following steps when called:</p>
<emu-alg><ol><li>If <var>completion</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7086"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, return <emu-val>true</emu-val>.</li><li>If <var>completion</var> is not a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7087"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">continue completion</a></emu-xref>, return <emu-val>false</emu-val>.</li><li>If <var>completion</var>.<var class="field">[[Target]]</var> is <emu-const>empty</emu-const>, return <emu-val>true</emu-val>.</li><li>If <var>labelSet</var> contains <var>completion</var>.<var class="field">[[Target]]</var>, return <emu-val>true</emu-val>.</li><li>Return <emu-val>false</emu-val>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Within the <emu-nt id="_ref_21643"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> part of an <emu-nt id="_ref_21644"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> a <emu-nt id="_ref_21645"><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a></emu-nt> may be used to begin a new iteration.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-runtime-semantics-loopevaluation" type="sdo" aoid="LoopEvaluation">
<h1><span class="secnum">14.7.1.2</span> Runtime Semantics: LoopEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7088"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> LoopEvaluation takes argument <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7089"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7090"><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_7091"><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_7092"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="IterationStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="wbcc1u-6" id="prod-bY0mbJsd"><emu-nt id="_ref_21646"><a href="ecmascript-language-statements-and-declarations.html#prod-DoWhileStatement">DoWhileStatement</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="DoWhileLoopEvaluation" id="_ref_7093"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-dowhileloopevaluation" class="e-user-code">DoWhileLoopEvaluation</a></emu-xref> of <emu-nt id="_ref_21647"><a href="ecmascript-language-statements-and-declarations.html#prod-DoWhileStatement">DoWhileStatement</a></emu-nt> with argument <var>labelSet</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="IterationStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="_jk9wnip" id="prod-pBcbxGRB"><emu-nt id="_ref_21648"><a href="ecmascript-language-statements-and-declarations.html#prod-WhileStatement">WhileStatement</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="WhileLoopEvaluation" id="_ref_7094"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-whileloopevaluation" class="e-user-code">WhileLoopEvaluation</a></emu-xref> of <emu-nt id="_ref_21649"><a href="ecmascript-language-statements-and-declarations.html#prod-WhileStatement">WhileStatement</a></emu-nt> with argument <var>labelSet</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="IterationStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="brkouqxh" id="prod-FuTGGBHg"><emu-nt id="_ref_21650"><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="ForLoopEvaluation" id="_ref_7095"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forloopevaluation" class="e-user-code">ForLoopEvaluation</a></emu-xref> of <emu-nt id="_ref_21651"><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt> with argument <var>labelSet</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="IterationStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="wium6lig" id="prod-RfvZcfJK"><emu-nt id="_ref_21652"><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="ForInOfLoopEvaluation" id="_ref_7096"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofloopevaluation" class="e-user-code">ForInOfLoopEvaluation</a></emu-xref> of <emu-nt id="_ref_21653"><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> with argument <var>labelSet</var>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-do-while-statement">
<h1><span class="secnum">14.7.2</span> The <code>do</code>-<code>while</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="DoWhileStatement" params="Yield, Await, Return" id="prod-DoWhileStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-DoWhileStatement">DoWhileStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="eiknjnpu" id="prod-9vnoeXX4">
<emu-t>do</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21654"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-t>while</emu-t>
<emu-t>(</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21655"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-do-while-statement-static-semantics-early-errors">
<h1><span class="secnum">14.7.2.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="DoWhileStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-DoWhileStatement">DoWhileStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jocmqoht">
<emu-t>do</emu-t>
<emu-nt id="_ref_21656"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
<emu-t>while</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21657"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7097"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<emu-nt id="_ref_21658"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>It is only necessary to apply this rule if the extension specified in <emu-xref href="#sec-labelled-function-declarations" id="_ref_445"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">B.3.1</a></emu-xref> is implemented.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-runtime-semantics-dowhileloopevaluation" oldids="sec-do-while-statement-runtime-semantics-labelledevaluation" type="sdo" aoid="DoWhileLoopEvaluation"><span id="sec-do-while-statement-runtime-semantics-labelledevaluation"></span>
<h1><span class="secnum">14.7.2.2</span> Runtime Semantics: DoWhileLoopEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7098"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> DoWhileLoopEvaluation takes argument <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7099"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7100"><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_7101"><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_7102"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="DoWhileStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-DoWhileStatement">DoWhileStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jocmqoht" id="prod-3uzJdijq">
<emu-t>do</emu-t>
<emu-nt id="_ref_21659"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
<emu-t>while</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21660"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>V</var> be <emu-val>undefined</emu-val>.</li><li>Repeat,<ol><li>Let <var>stmtResult</var> be <emu-xref aoid="Completion" id="_ref_7103"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7104"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21661"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>).</li><li>If <emu-xref aoid="LoopContinues" id="_ref_7105"><a href="ecmascript-language-statements-and-declarations.html#sec-loopcontinues">LoopContinues</a></emu-xref>(<var>stmtResult</var>, <var>labelSet</var>) is <emu-val>false</emu-val>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7106"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>stmtResult</var>, <var>V</var>).</li><li>If <var>stmtResult</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>stmtResult</var>.<var class="field">[[Value]]</var>.</li><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7107"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21662"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>exprValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7108"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_7109"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>exprValue</var>) is <emu-val>false</emu-val>, return <var>V</var>.</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-while-statement">
<h1><span class="secnum">14.7.3</span> The <code>while</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="WhileStatement" params="Yield, Await, Return" id="prod-WhileStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-WhileStatement">WhileStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="awcw0xuh" id="prod-Tx40AFG0">
<emu-t>while</emu-t>
<emu-t>(</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21663"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21664"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-while-statement-static-semantics-early-errors">
<h1><span class="secnum">14.7.3.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="WhileStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-WhileStatement">WhileStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="92j78-b5">
<emu-t>while</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21665"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21666"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7110"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<emu-nt id="_ref_21667"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>It is only necessary to apply this rule if the extension specified in <emu-xref href="#sec-labelled-function-declarations" id="_ref_446"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">B.3.1</a></emu-xref> is implemented.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-runtime-semantics-whileloopevaluation" oldids="sec-while-statement-runtime-semantics-labelledevaluation" type="sdo" aoid="WhileLoopEvaluation"><span id="sec-while-statement-runtime-semantics-labelledevaluation"></span>
<h1><span class="secnum">14.7.3.2</span> Runtime Semantics: WhileLoopEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7111"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> WhileLoopEvaluation takes argument <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7112"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7113"><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_7114"><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_7115"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="WhileStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-WhileStatement">WhileStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="92j78-b5" id="prod-0mdwhc7l">
<emu-t>while</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21668"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21669"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>V</var> be <emu-val>undefined</emu-val>.</li><li>Repeat,<ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7116"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21670"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>exprValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7117"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_7118"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>exprValue</var>) is <emu-val>false</emu-val>, return <var>V</var>.</li><li>Let <var>stmtResult</var> be <emu-xref aoid="Completion" id="_ref_7119"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7120"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21671"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>).</li><li>If <emu-xref aoid="LoopContinues" id="_ref_7121"><a href="ecmascript-language-statements-and-declarations.html#sec-loopcontinues">LoopContinues</a></emu-xref>(<var>stmtResult</var>, <var>labelSet</var>) is <emu-val>false</emu-val>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7122"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>stmtResult</var>, <var>V</var>).</li><li>If <var>stmtResult</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>stmtResult</var>.<var class="field">[[Value]]</var>.</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-for-statement">
<h1><span class="secnum">14.7.4</span> The <code>for</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="ForStatement" params="Yield, Await, Return" id="prod-ForStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="honbm3zg" id="prod-NvPgd2yM">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-gann>[lookahead ≠ <emu-t>let</emu-t>
<emu-t>[</emu-t>]</emu-gann>
<emu-nt params="~In, ?Yield, ?Await" optional="" id="_ref_21672"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[~In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21673"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21674"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21675"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="frhzdc45" id="prod-pYXfSJG_">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt params="~In, ?Yield, ?Await" id="_ref_21676"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a><emu-mods><emu-params>[~In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21677"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21678"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21679"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="ibe-o3pw" id="prod-0Y0bZAvD">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt params="~In, ?Yield, ?Await" id="_ref_21680"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a><emu-mods><emu-params>[~In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21681"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt params="+In, ?Yield, ?Await" optional="" id="_ref_21682"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21683"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-for-statement-static-semantics-early-errors">
<h1><span class="secnum">14.7.4.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="ForStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="_do88got">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt optional="" id="_ref_21684"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21685"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21686"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21687"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="sodmtko8">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21688"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21689"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21690"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21691"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="k8b-ryxj">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21692"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt>
<emu-nt optional="" id="_ref_21693"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21694"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21695"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7123"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<emu-nt id="_ref_21696"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>It is only necessary to apply this rule if the extension specified in <emu-xref href="#sec-labelled-function-declarations" id="_ref_447"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">B.3.1</a></emu-xref> is implemented.</p>
</div></emu-note>
<emu-grammar><emu-production name="ForStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="k8b-ryxj">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21697"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt>
<emu-nt optional="" id="_ref_21698"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21699"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21700"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if any element of the <emu-xref aoid="BoundNames" id="_ref_7124"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21701"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt> also occurs in the <emu-xref aoid="VarDeclaredNames" id="_ref_7125"><a href="syntax-directed-operations.html#sec-static-semantics-vardeclarednames">VarDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21702"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-runtime-semantics-forloopevaluation" oldids="sec-for-statement-runtime-semantics-labelledevaluation" type="sdo" aoid="ForLoopEvaluation"><span id="sec-for-statement-runtime-semantics-labelledevaluation"></span>
<h1><span class="secnum">14.7.4.2</span> Runtime Semantics: ForLoopEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7126"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> ForLoopEvaluation takes argument <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7127"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7128"><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_7129"><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_7130"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="ForStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="_do88got" id="prod-qUCVnDNm">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt optional="" id="_ref_21703"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21704"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21705"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21706"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>If the first <emu-nt id="_ref_21707"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, then<ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7131"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of the first <emu-nt id="_ref_21708"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Perform ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7132"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li></ol></li><li>If the second <emu-nt id="_ref_21709"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, let <var>test</var> be the second <emu-nt id="_ref_21710"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>; else let <var>test</var> be <emu-const>empty</emu-const>.</li><li>If the third <emu-nt id="_ref_21711"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, let <var>increment</var> be the third <emu-nt id="_ref_21712"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>; else let <var>increment</var> be <emu-const>empty</emu-const>.</li><li>Return ?&nbsp;<emu-xref aoid="ForBodyEvaluation" id="_ref_7133"><a href="ecmascript-language-statements-and-declarations.html#sec-forbodyevaluation" class="e-user-code">ForBodyEvaluation</a></emu-xref>(<var>test</var>, <var>increment</var>, <emu-nt id="_ref_21713"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, «&nbsp;», <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="sodmtko8" id="prod-HwfL-Win">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21714"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21715"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21716"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21717"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Perform ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7134"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21718"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableDeclarationList">VariableDeclarationList</a></emu-nt>.</li><li>If the first <emu-nt id="_ref_21719"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, let <var>test</var> be the first <emu-nt id="_ref_21720"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>; else let <var>test</var> be <emu-const>empty</emu-const>.</li><li>If the second <emu-nt id="_ref_21721"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, let <var>increment</var> be the second <emu-nt id="_ref_21722"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>; else let <var>increment</var> be <emu-const>empty</emu-const>.</li><li>Return ?&nbsp;<emu-xref aoid="ForBodyEvaluation" id="_ref_7135"><a href="ecmascript-language-statements-and-declarations.html#sec-forbodyevaluation" class="e-user-code">ForBodyEvaluation</a></emu-xref>(<var>test</var>, <var>increment</var>, <emu-nt id="_ref_21723"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, «&nbsp;», <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForStatement">ForStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="k8b-ryxj" id="prod-PMtIFugG">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21724"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt>
<emu-nt optional="" id="_ref_21725"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>;</emu-t>
<emu-nt optional="" id="_ref_21726"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21727"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7136"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>loopEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_7137"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>oldEnv</var>).</li><li>Let <var>isConst</var> be <emu-xref aoid="IsConstantDeclaration" id="_ref_7138"><a href="syntax-directed-operations.html#sec-static-semantics-isconstantdeclaration">IsConstantDeclaration</a></emu-xref> of <emu-nt id="_ref_21728"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt>.</li><li>Let <var>boundNames</var> be the <emu-xref aoid="BoundNames" id="_ref_7139"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21729"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt>.</li><li>For each element <var>dn</var> of <var>boundNames</var>, do<ol><li>If <var>isConst</var> is <emu-val>true</emu-val>, then<ol><li>Perform !&nbsp;<var>loopEnv</var>.<emu-xref aoid="CreateImmutableBinding" id="_ref_7140"><a href="executable-code-and-execution-contexts.html#abstract-createimmutablebinding">CreateImmutableBinding</a></emu-xref>(<var>dn</var>, <emu-val>true</emu-val>).</li></ol></li><li>Else,<ol><li>Perform !&nbsp;<var>loopEnv</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_7141"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>dn</var>, <emu-val>false</emu-val>).</li></ol></li></ol></li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7142"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>loopEnv</var>.</li><li>Let <var>forDcl</var> be <emu-xref aoid="Completion" id="_ref_7143"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7144"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21730"><a href="ecmascript-language-statements-and-declarations.html#prod-LexicalDeclaration">LexicalDeclaration</a></emu-nt>).</li><li>If <var>forDcl</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7145"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Set the <emu-xref href="#running-execution-context" id="_ref_7146"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return ?&nbsp;<var>forDcl</var>.</li></ol></li><li>If <var>isConst</var> is <emu-val>false</emu-val>, let <var>perIterationLets</var> be <var>boundNames</var>; else let <var>perIterationLets</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7147"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>If the first <emu-nt id="_ref_21731"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, let <var>test</var> be the first <emu-nt id="_ref_21732"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>; else let <var>test</var> be <emu-const>empty</emu-const>.</li><li>If the second <emu-nt id="_ref_21733"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is present, let <var>increment</var> be the second <emu-nt id="_ref_21734"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>; else let <var>increment</var> be <emu-const>empty</emu-const>.</li><li>Let <var>bodyResult</var> be <emu-xref aoid="Completion" id="_ref_7148"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="ForBodyEvaluation" id="_ref_7149"><a href="ecmascript-language-statements-and-declarations.html#sec-forbodyevaluation" class="e-user-code">ForBodyEvaluation</a></emu-xref>(<var>test</var>, <var>increment</var>, <emu-nt id="_ref_21735"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>perIterationLets</var>, <var>labelSet</var>)).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7150"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return ?&nbsp;<var>bodyResult</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-forbodyevaluation" type="abstract operation" aoid="ForBodyEvaluation">
<h1><span class="secnum">14.7.4.3</span> ForBodyEvaluation ( <var>test</var>, <var>increment</var>, <var>stmt</var>, <var>perIterationBindings</var>, <var>labelSet</var> )</h1>
<p>The abstract operation ForBodyEvaluation takes arguments <var>test</var> (an <emu-nt id="_ref_21736"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7151"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> or <emu-const>empty</emu-const>), <var>increment</var> (an <emu-nt id="_ref_21737"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7152"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> or <emu-const>empty</emu-const>), <var>stmt</var> (a <emu-nt id="_ref_21738"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7153"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>), <var>perIterationBindings</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7154"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings), and <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7155"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7156"><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_7157"><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_7158"><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>V</var> be <emu-val>undefined</emu-val>.</li><li>Perform ?&nbsp;<emu-xref aoid="CreatePerIterationEnvironment" id="_ref_7159"><a href="ecmascript-language-statements-and-declarations.html#sec-createperiterationenvironment">CreatePerIterationEnvironment</a></emu-xref>(<var>perIterationBindings</var>).</li><li>Repeat,<ol><li>If <var>test</var> is not <emu-const>empty</emu-const>, then<ol><li>Let <var>testRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7160"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>test</var>.</li><li>Let <var>testValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7161"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>testRef</var>).</li><li>If <emu-xref aoid="ToBoolean" id="_ref_7162"><a href="abstract-operations.html#sec-toboolean">ToBoolean</a></emu-xref>(<var>testValue</var>) is <emu-val>false</emu-val>, return <var>V</var>.</li></ol></li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_7163"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7164"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>stmt</var>).</li><li>If <emu-xref aoid="LoopContinues" id="_ref_7165"><a href="ecmascript-language-statements-and-declarations.html#sec-loopcontinues">LoopContinues</a></emu-xref>(<var>result</var>, <var>labelSet</var>) is <emu-val>false</emu-val>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7166"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>result</var>, <var>V</var>).</li><li>If <var>result</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>result</var>.<var class="field">[[Value]]</var>.</li><li>Perform ?&nbsp;<emu-xref aoid="CreatePerIterationEnvironment" id="_ref_7167"><a href="ecmascript-language-statements-and-declarations.html#sec-createperiterationenvironment">CreatePerIterationEnvironment</a></emu-xref>(<var>perIterationBindings</var>).</li><li>If <var>increment</var> is not <emu-const>empty</emu-const>, then<ol><li>Let <var>incRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7168"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>increment</var>.</li><li>Perform ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7169"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>incRef</var>).</li></ol></li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-createperiterationenvironment" type="abstract operation" aoid="CreatePerIterationEnvironment">
<h1><span class="secnum">14.7.4.4</span> CreatePerIterationEnvironment ( <var>perIterationBindings</var> )</h1>
<p>The abstract operation CreatePerIterationEnvironment takes argument <var>perIterationBindings</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7170"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7171"><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_7172"><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>If <var>perIterationBindings</var> has any elements, then<ol><li>Let <var>lastIterationEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7173"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>outer</var> be <var>lastIterationEnv</var>.<var class="field">[[OuterEnv]]</var>.</li><li><emu-xref href="#assert" id="_ref_7174"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>outer</var> is not <emu-val>null</emu-val>.</li><li>Let <var>thisIterationEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_7175"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>outer</var>).</li><li>For each element <var>bn</var> of <var>perIterationBindings</var>, do<ol><li>Perform !&nbsp;<var>thisIterationEnv</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_7176"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>bn</var>, <emu-val>false</emu-val>).</li><li>Let <var>lastValue</var> be ?&nbsp;<var>lastIterationEnv</var>.<emu-xref aoid="GetBindingValue" id="_ref_7177"><a href="executable-code-and-execution-contexts.html#abstract-getbindingvalue">GetBindingValue</a></emu-xref>(<var>bn</var>, <emu-val>true</emu-val>).</li><li>Perform !&nbsp;<var>thisIterationEnv</var>.<emu-xref aoid="InitializeBinding" id="_ref_7178"><a href="executable-code-and-execution-contexts.html#abstract-initializebinding">InitializeBinding</a></emu-xref>(<var>bn</var>, <var>lastValue</var>).</li></ol></li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7179"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>thisIterationEnv</var>.</li></ol></li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-for-in-and-for-of-statements">
<h1><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</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="ForInOfStatement" params="Yield, Await, Return" id="prod-ForInOfStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="w0xbna_a" id="prod-Za8VIr4f">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-gann>[lookahead ≠ <emu-t>let</emu-t>
<emu-t>[</emu-t>]</emu-gann>
<emu-nt params="?Yield, ?Await" id="_ref_21739"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>in</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21740"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21741"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="7ml0tbdi" id="prod-_N8Q-kim">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21742"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>in</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21743"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21744"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="zchtsyje" id="prod-xutvwaXc">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21745"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>in</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21746"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21747"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="e8xfsfow" id="prod-nLtPS4oB">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-gann>[lookahead ∉ { <emu-t>let</emu-t>, <emu-t>async</emu-t>
<emu-t>of</emu-t> }]</emu-gann>
<emu-nt params="?Yield, ?Await" id="_ref_21748"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>of</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21749"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21750"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="58n_2ihn" id="prod-M1zjKbr6">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21751"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>of</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21752"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21753"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="pfvjbka1" id="prod-EoyoF5LI">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21754"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>of</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21755"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21756"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="oprokwwm" constraints="+Await" id="prod-ReDwT2-b"><emu-constraints>[+Await]</emu-constraints>
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-gann>[lookahead ≠ <emu-t>let</emu-t>]</emu-gann>
<emu-nt params="?Yield, ?Await" id="_ref_21757"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>of</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21758"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21759"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="9bsmrb_a" constraints="+Await" id="prod-ut_uoPzp"><emu-constraints>[+Await]</emu-constraints>
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21760"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>of</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21761"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21762"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="fxca1-1x" constraints="+Await" id="prod-jY1gwM9V"><emu-constraints>[+Await]</emu-constraints>
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_21763"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>of</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21764"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21765"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="ForDeclaration" params="Yield, Await" id="prod-ForDeclaration">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="k6i8qvu4" id="prod-ygJ0cdk1">
<emu-nt id="_ref_21766"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt params="?Yield, ?Await" id="_ref_21767"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="ForBinding" params="Yield, Await" id="prod-ForBinding">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ir-rfjfi" id="prod-gwk9Iaq2">
<emu-nt params="?Yield, ?Await" id="_ref_21768"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="nridwfya" id="prod-rDLkyb_q">
<emu-nt params="?Yield, ?Await" id="_ref_21769"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This section is extended by Annex <emu-xref href="#sec-initializers-in-forin-statement-heads" id="_ref_448"><a href="additional-ecmascript-features-for-web-browsers.html#sec-initializers-in-forin-statement-heads">B.3.5</a></emu-xref>.</p>
</div></emu-note>
<emu-clause id="sec-for-in-and-for-of-statements-static-semantics-early-errors">
<h1><span class="secnum">14.7.5.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="ForInOfStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="v1ibcd1w">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21770"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21771"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21772"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="7pgjrcn-">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21773"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21774"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21775"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="jzctgxkp">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21776"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21777"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21778"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="jqzgi_en">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21779"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21780"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21781"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="7m-adytu">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21782"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21783"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21784"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="b3wzboyu">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21785"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21786"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21787"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="mhrux1r7">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21788"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21789"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21790"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="cyt_lv_1">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21791"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21792"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21793"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="uatmda3j">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21794"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21795"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21796"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7180"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<emu-nt id="_ref_21797"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>It is only necessary to apply this rule if the extension specified in <emu-xref href="#sec-labelled-function-declarations" id="_ref_449"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">B.3.1</a></emu-xref> is implemented.</p>
</div></emu-note>
<emu-grammar><emu-production name="ForInOfStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="v1ibcd1w">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21798"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21799"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21800"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="jqzgi_en">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21801"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21802"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21803"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="mhrux1r7">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21804"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21805"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21806"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
If <emu-nt id="_ref_21807"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt> is either an <emu-nt id="_ref_21808"><a href="ecmascript-language-expressions.html#prod-ObjectLiteral">ObjectLiteral</a></emu-nt> or an <emu-nt id="_ref_21809"><a href="ecmascript-language-expressions.html#prod-ArrayLiteral">ArrayLiteral</a></emu-nt>, <emu-nt id="_ref_21810"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt> <emu-xref href="#must-cover" id="_ref_7181"><a href="notational-conventions.html#must-cover">must cover</a></emu-xref> an <emu-nt id="_ref_21811"><a href="ecmascript-language-expressions.html#prod-AssignmentPattern">AssignmentPattern</a></emu-nt>.
</li>
<li>
If <emu-nt id="_ref_21812"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt> is neither an <emu-nt id="_ref_21813"><a href="ecmascript-language-expressions.html#prod-ObjectLiteral">ObjectLiteral</a></emu-nt> nor an <emu-nt id="_ref_21814"><a href="ecmascript-language-expressions.html#prod-ArrayLiteral">ArrayLiteral</a></emu-nt>, it is a Syntax Error if the <emu-xref aoid="AssignmentTargetType" id="_ref_7182"><a href="syntax-directed-operations.html#sec-static-semantics-assignmenttargettype">AssignmentTargetType</a></emu-xref> of <emu-nt id="_ref_21815"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt> is <emu-const>invalid</emu-const>.
</li>
</ul>
<emu-grammar><emu-production name="ForInOfStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jzctgxkp">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21816"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21817"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21818"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="b3wzboyu">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21819"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21820"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21821"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
<emu-rhs a="uatmda3j">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21822"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21823"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21824"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if the <emu-xref aoid="BoundNames" id="_ref_7183"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21825"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt> contains <emu-val>"let"</emu-val>.
</li>
<li>
It is a Syntax Error if any element of the <emu-xref aoid="BoundNames" id="_ref_7184"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21826"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt> also occurs in the <emu-xref aoid="VarDeclaredNames" id="_ref_7185"><a href="syntax-directed-operations.html#sec-static-semantics-vardeclarednames">VarDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21827"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>.
</li>
<li>
It is a Syntax Error if the <emu-xref aoid="BoundNames" id="_ref_7186"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21828"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt> contains any duplicate entries.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-static-semantics-isdestructuring" oldids="sec-static-semantics-static-semantics-isdestructuring,sec-for-in-and-for-of-statements-static-semantics-isdestructuring" type="sdo" aoid="IsDestructuring"><span id="sec-for-in-and-for-of-statements-static-semantics-isdestructuring"></span><span id="sec-static-semantics-static-semantics-isdestructuring"></span>
<h1><span class="secnum">14.7.5.2</span> Static Semantics: IsDestructuring</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7187"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> IsDestructuring takes no arguments and returns a Boolean. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="MemberExpression" collapsed="">
<emu-nt><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jvcvemtw" id="prod-HvnSrzbi"><emu-nt id="_ref_21829"><a href="ecmascript-language-expressions.html#prod-PrimaryExpression">PrimaryExpression</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>If <emu-nt id="_ref_21830"><a href="ecmascript-language-expressions.html#prod-PrimaryExpression">PrimaryExpression</a></emu-nt> is either an <emu-nt id="_ref_21831"><a href="ecmascript-language-expressions.html#prod-ObjectLiteral">ObjectLiteral</a></emu-nt> or an <emu-nt id="_ref_21832"><a href="ecmascript-language-expressions.html#prod-ArrayLiteral">ArrayLiteral</a></emu-nt>, return <emu-val>true</emu-val>.</li><li>Return <emu-val>false</emu-val>.</li></ol></emu-alg>
<emu-grammar><emu-production name="MemberExpression">
<emu-nt><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="a74xd7de" id="prod-nfrnC2qv">
<emu-nt id="_ref_21833"><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt>
<emu-t>[</emu-t>
<emu-nt id="_ref_21834"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>]</emu-t>
</emu-rhs>
<emu-rhs a="frbj984t" id="prod-pVCOt4bB">
<emu-nt id="_ref_21835"><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt>
<emu-t>.</emu-t>
<emu-nt id="_ref_21836"><a href="ecmascript-language-lexical-grammar.html#prod-IdentifierName">IdentifierName</a></emu-nt>
</emu-rhs>
<emu-rhs a="fj52gjle" id="prod-IOJOqU1K">
<emu-nt id="_ref_21837"><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt>
<emu-nt id="_ref_21838"><a href="ecmascript-language-expressions.html#prod-TemplateLiteral">TemplateLiteral</a></emu-nt>
</emu-rhs>
<emu-rhs a="x4tzletw" id="prod-e3LgGUUv">
<emu-nt id="_ref_21839"><a href="ecmascript-language-expressions.html#prod-SuperProperty">SuperProperty</a></emu-nt>
</emu-rhs>
<emu-rhs a="yb7id2be" id="prod-uCaMN-Ha">
<emu-nt id="_ref_21840"><a href="ecmascript-language-expressions.html#prod-MetaProperty">MetaProperty</a></emu-nt>
</emu-rhs>
<emu-rhs a="cfq-hbbx" id="prod-vPeih5lN">
<emu-t>new</emu-t>
<emu-nt id="_ref_21841"><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt>
<emu-nt id="_ref_21842"><a href="ecmascript-language-expressions.html#prod-Arguments">Arguments</a></emu-nt>
</emu-rhs>
<emu-rhs a="0uk9afbi" id="prod-IWE0dD8s">
<emu-nt id="_ref_21843"><a href="ecmascript-language-expressions.html#prod-MemberExpression">MemberExpression</a></emu-nt>
<emu-t>.</emu-t>
<emu-nt id="_ref_21844"><a href="ecmascript-language-lexical-grammar.html#prod-PrivateIdentifier">PrivateIdentifier</a></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="NewExpression">
<emu-nt><a href="ecmascript-language-expressions.html#prod-NewExpression">NewExpression</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="51p618ta" id="prod-fNvFZX0j">
<emu-t>new</emu-t>
<emu-nt id="_ref_21845"><a href="ecmascript-language-expressions.html#prod-NewExpression">NewExpression</a></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="LeftHandSideExpression">
<emu-nt><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="i8det4ck" id="prod-9Ion7RwA">
<emu-nt id="_ref_21846"><a href="ecmascript-language-expressions.html#prod-CallExpression">CallExpression</a></emu-nt>
</emu-rhs>
<emu-rhs a="jbet6xpw" id="prod-Q5WdRWI1">
<emu-nt id="_ref_21847"><a href="ecmascript-language-expressions.html#prod-OptionalExpression">OptionalExpression</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-val>false</emu-val>.</li></ol></emu-alg>
<emu-grammar><emu-production name="ForDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="0y1vvm1x" id="prod-gowHZDoa">
<emu-nt id="_ref_21848"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt id="_ref_21849"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-xref aoid="IsDestructuring" id="_ref_7188"><a href="ecmascript-language-statements-and-declarations.html#sec-static-semantics-isdestructuring">IsDestructuring</a></emu-xref> of <emu-nt id="_ref_21850"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>.</li></ol></emu-alg>
<emu-grammar><emu-production name="ForBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uolyom43" id="prod-AsYWUqR1"><emu-nt id="_ref_21851"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-val>false</emu-val>.</li></ol></emu-alg>
<emu-grammar><emu-production name="ForBinding" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="mdrfyhm6" id="prod-n6CWa3rF"><emu-nt id="_ref_21852"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-val>true</emu-val>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This section is extended by Annex <emu-xref href="#sec-initializers-in-forin-statement-heads" id="_ref_450"><a href="additional-ecmascript-features-for-web-browsers.html#sec-initializers-in-forin-statement-heads">B.3.5</a></emu-xref>.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-runtime-semantics-fordeclarationbindinginitialization" oldids="sec-for-in-and-for-of-statements-runtime-semantics-bindinginitialization" type="sdo" aoid="ForDeclarationBindingInitialization"><span id="sec-for-in-and-for-of-statements-runtime-semantics-bindinginitialization"></span>
<h1><span class="secnum">14.7.5.3</span> Runtime Semantics: ForDeclarationBindingInitialization</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7189"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> ForDeclarationBindingInitialization takes arguments <var>value</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7190"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types">ECMAScript language value</a></emu-xref>) and <var>environment</var> (an <emu-xref href="#sec-environment-records" id="_ref_7191"><a href="executable-code-and-execution-contexts.html#sec-environment-records">Environment Record</a></emu-xref> or <emu-val>undefined</emu-val>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7192"><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 an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7193"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>.</p>
<emu-note><span class="note">Note</span><div class="note-contents">
<p><emu-val>undefined</emu-val> is passed for <var>environment</var> to indicate that a <emu-xref aoid="PutValue" id="_ref_7194"><a href="ecmascript-data-types-and-values.html#sec-putvalue">PutValue</a></emu-xref> operation should be used to assign the initialization value. This is the case for <code>var</code> statements and the formal parameter lists of some <emu-xref href="#non-strict-function" id="_ref_7195"><a href="ordinary-and-exotic-objects-behaviours.html#non-strict-function">non-strict functions</a></emu-xref> (see <emu-xref href="#sec-functiondeclarationinstantiation" id="_ref_451"><a href="ordinary-and-exotic-objects-behaviours.html#sec-functiondeclarationinstantiation">10.2.11</a></emu-xref>). In those cases a lexical binding is hoisted and preinitialized prior to evaluation of its initializer.</p>
</div></emu-note>
<p>It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="ForDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="0y1vvm1x" id="prod-S5lZ05os">
<emu-nt id="_ref_21853"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt id="_ref_21854"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="BindingInitialization" id="_ref_7196"><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" class="e-user-code">BindingInitialization</a></emu-xref> of <emu-nt id="_ref_21855"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt> with arguments <var>value</var> and <var>environment</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-runtime-semantics-fordeclarationbindinginstantiation" oldids="sec-runtime-semantics-bindinginstantiation" type="sdo" aoid="ForDeclarationBindingInstantiation"><span id="sec-runtime-semantics-bindinginstantiation"></span>
<h1><span class="secnum">14.7.5.4</span> Runtime Semantics: ForDeclarationBindingInstantiation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7197"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> ForDeclarationBindingInstantiation takes argument <var>environment</var> (a <emu-xref href="#sec-declarative-environment-records" id="_ref_7198"><a href="executable-code-and-execution-contexts.html#sec-declarative-environment-records">Declarative Environment Record</a></emu-xref>) and returns <emu-const>unused</emu-const>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="ForDeclaration" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="0y1vvm1x" id="prod-bTiDTykL">
<emu-nt id="_ref_21856"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt>
<emu-nt id="_ref_21857"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>For each element <var>name</var> of the <emu-xref aoid="BoundNames" id="_ref_7199"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21858"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>, do<ol><li>If <emu-xref aoid="IsConstantDeclaration" id="_ref_7200"><a href="syntax-directed-operations.html#sec-static-semantics-isconstantdeclaration">IsConstantDeclaration</a></emu-xref> of <emu-nt id="_ref_21859"><a href="ecmascript-language-statements-and-declarations.html#prod-LetOrConst">LetOrConst</a></emu-nt> is <emu-val>true</emu-val>, then<ol><li>Perform !&nbsp;<var>environment</var>.<emu-xref aoid="CreateImmutableBinding" id="_ref_7201"><a href="executable-code-and-execution-contexts.html#abstract-createimmutablebinding">CreateImmutableBinding</a></emu-xref>(<var>name</var>, <emu-val>true</emu-val>).</li></ol></li><li>Else,<ol><li>Perform !&nbsp;<var>environment</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_7202"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>name</var>, <emu-val>false</emu-val>).</li></ol></li></ol></li><li>Return <emu-const>unused</emu-const>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-runtime-semantics-forinofloopevaluation" oldids="sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation" type="sdo" aoid="ForInOfLoopEvaluation"><span id="sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation"></span>
<h1><span class="secnum">14.7.5.5</span> Runtime Semantics: ForInOfLoopEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7203"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> ForInOfLoopEvaluation takes argument <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7204"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7205"><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_7206"><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_7207"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="v1ibcd1w" id="prod-dhS3iRZF">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21860"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21861"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21862"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7208"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(«&nbsp;», <emu-nt id="_ref_21863"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>, <emu-const>enumerate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7209"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21864"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>, <emu-nt id="_ref_21865"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>enumerate</emu-const>, <emu-const>assignment</emu-const>, <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="7pgjrcn-" id="prod-A6rVBZNm">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21866"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21867"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21868"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7210"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(«&nbsp;», <emu-nt id="_ref_21869"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>, <emu-const>enumerate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7211"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21870"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>, <emu-nt id="_ref_21871"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>enumerate</emu-const>, <emu-const>var-binding</emu-const>, <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jzctgxkp" id="prod-zcGoySgU">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21872"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>in</emu-t>
<emu-nt id="_ref_21873"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21874"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7212"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(<emu-xref aoid="BoundNames" id="_ref_7213"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21875"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>, <emu-nt id="_ref_21876"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>, <emu-const>enumerate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7214"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21877"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>, <emu-nt id="_ref_21878"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>enumerate</emu-const>, <emu-const>lexical-binding</emu-const>, <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="jqzgi_en" id="prod-xXfkt6k0">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21879"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21880"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21881"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7215"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(«&nbsp;», <emu-nt id="_ref_21882"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>, <emu-const>iterate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7216"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21883"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>, <emu-nt id="_ref_21884"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>iterate</emu-const>, <emu-const>assignment</emu-const>, <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="7m-adytu" id="prod-pPrWP7Ph">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21885"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21886"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21887"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7217"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(«&nbsp;», <emu-nt id="_ref_21888"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>, <emu-const>iterate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7218"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21889"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>, <emu-nt id="_ref_21890"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>iterate</emu-const>, <emu-const>var-binding</emu-const>, <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="b3wzboyu" id="prod-OIo-GNlm">
<emu-t>for</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21891"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21892"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21893"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7219"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(<emu-xref aoid="BoundNames" id="_ref_7220"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21894"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>, <emu-nt id="_ref_21895"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>, <emu-const>iterate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7221"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21896"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>, <emu-nt id="_ref_21897"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>iterate</emu-const>, <emu-const>lexical-binding</emu-const>, <var>labelSet</var>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="mhrux1r7" id="prod-Z4scLosS">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21898"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21899"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21900"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7222"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(«&nbsp;», <emu-nt id="_ref_21901"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>, <emu-const>async-iterate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7223"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21902"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>, <emu-nt id="_ref_21903"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>iterate</emu-const>, <emu-const>assignment</emu-const>, <var>labelSet</var>, <emu-const>async</emu-const>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="cyt_lv_1" id="prod-5PDN6AV3">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-t>var</emu-t>
<emu-nt id="_ref_21904"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21905"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21906"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7224"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(«&nbsp;», <emu-nt id="_ref_21907"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>, <emu-const>async-iterate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7225"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21908"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>, <emu-nt id="_ref_21909"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>iterate</emu-const>, <emu-const>var-binding</emu-const>, <var>labelSet</var>, <emu-const>async</emu-const>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ForInOfStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ForInOfStatement">ForInOfStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uatmda3j" id="prod-KdWnMB6i">
<emu-t>for</emu-t>
<emu-t>await</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21910"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>
<emu-t>of</emu-t>
<emu-nt id="_ref_21911"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21912"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>keyResult</var> be ?&nbsp;<emu-xref aoid="ForIn/OfHeadEvaluation" id="_ref_7226"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forinofheadevaluation" class="e-user-code">ForIn/OfHeadEvaluation</a></emu-xref>(<emu-xref aoid="BoundNames" id="_ref_7227"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_21913"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>, <emu-nt id="_ref_21914"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt>, <emu-const>async-iterate</emu-const>).</li><li>Return ?&nbsp;<emu-xref aoid="ForIn/OfBodyEvaluation" id="_ref_7228"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" class="e-user-code">ForIn/OfBodyEvaluation</a></emu-xref>(<emu-nt id="_ref_21915"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>, <emu-nt id="_ref_21916"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, <var>keyResult</var>, <emu-const>iterate</emu-const>, <emu-const>lexical-binding</emu-const>, <var>labelSet</var>, <emu-const>async</emu-const>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This section is extended by Annex <emu-xref href="#sec-initializers-in-forin-statement-heads" id="_ref_452"><a href="additional-ecmascript-features-for-web-browsers.html#sec-initializers-in-forin-statement-heads">B.3.5</a></emu-xref>.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-runtime-semantics-forinofheadevaluation" type="abstract operation" oldids="sec-runtime-semantics-forin-div-ofheadevaluation-tdznames-expr-iterationkind" aoid="ForIn/OfHeadEvaluation"><span id="sec-runtime-semantics-forin-div-ofheadevaluation-tdznames-expr-iterationkind"></span>
<h1><span class="secnum">14.7.5.6</span> ForIn/OfHeadEvaluation ( <var>uninitializedBoundNames</var>, <var>expr</var>, <var>iterationKind</var> )</h1>
<p>The abstract operation ForIn/OfHeadEvaluation takes arguments <var>uninitializedBoundNames</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7229"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings), <var>expr</var> (an <emu-nt id="_ref_21917"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7230"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref> or an <emu-nt id="_ref_21918"><a href="ecmascript-language-expressions.html#prod-AssignmentExpression">AssignmentExpression</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7231"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>), and <var>iterationKind</var> (<emu-const>enumerate</emu-const>, <emu-const>iterate</emu-const>, or <emu-const>async-iterate</emu-const>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7232"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> an <emu-xref href="#sec-iterator-records" id="_ref_7233"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7234"><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>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7235"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>If <var>uninitializedBoundNames</var> is not empty, then<ol><li><emu-xref href="#assert" id="_ref_7236"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>uninitializedBoundNames</var> has no duplicate entries.</li><li>Let <var>newEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_7237"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>oldEnv</var>).</li><li>For each String <var>name</var> of <var>uninitializedBoundNames</var>, do<ol><li>Perform !&nbsp;<var>newEnv</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_7238"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>name</var>, <emu-val>false</emu-val>).</li></ol></li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7239"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>newEnv</var>.</li></ol></li><li>Let <var>exprRef</var> be <emu-xref aoid="Completion" id="_ref_7240"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7241"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>expr</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7242"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Let <var>exprValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7243"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(? <var>exprRef</var>).</li><li>If <var>iterationKind</var> is <emu-const>enumerate</emu-const>, then<ol><li>If <var>exprValue</var> is either <emu-val>undefined</emu-val> or <emu-val>null</emu-val>, then<ol><li>Return <emu-xref href="#sec-completion-record-specification-type" id="_ref_7244"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> { <var class="field">[[Type]]</var>: <emu-const>break</emu-const>, <var class="field">[[Value]]</var>: <emu-const>empty</emu-const>, <var class="field">[[Target]]</var>: <emu-const>empty</emu-const>&nbsp;}.</li></ol></li><li>Let <var>obj</var> be !&nbsp;<emu-xref aoid="ToObject" id="_ref_7245"><a href="abstract-operations.html#sec-toobject">ToObject</a></emu-xref>(<var>exprValue</var>).</li><li>Let <var>iterator</var> be <emu-xref aoid="EnumerateObjectProperties" id="_ref_7246"><a href="ecmascript-language-statements-and-declarations.html#sec-enumerate-object-properties">EnumerateObjectProperties</a></emu-xref>(<var>obj</var>).</li><li>Let <var>nextMethod</var> be !&nbsp;<emu-xref aoid="GetV" id="_ref_7247"><a href="abstract-operations.html#sec-getv">GetV</a></emu-xref>(<var>iterator</var>, <emu-val>"next"</emu-val>).</li><li>Return the <emu-xref href="#sec-iterator-records" id="_ref_7248"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref> { <var class="field">[[Iterator]]</var>: <var>iterator</var>, <var class="field">[[NextMethod]]</var>: <var>nextMethod</var>, <var class="field">[[Done]]</var>: <emu-val>false</emu-val>&nbsp;}.</li></ol></li><li><emu-xref href="#assert" id="_ref_7249"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>iterationKind</var> is either <emu-const>iterate</emu-const> or <emu-const>async-iterate</emu-const>.</li><li>If <var>iterationKind</var> is <emu-const>async-iterate</emu-const>, let <var>iteratorKind</var> be <emu-const>async</emu-const>.</li><li>Else, let <var>iteratorKind</var> be <emu-const>sync</emu-const>.</li><li>Return ?&nbsp;<emu-xref aoid="GetIterator" id="_ref_7250"><a href="abstract-operations.html#sec-getiterator" class="e-user-code">GetIterator</a></emu-xref>(<var>exprValue</var>, <var>iteratorKind</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset" type="abstract operation" aoid="ForIn/OfBodyEvaluation">
<h1><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> ] )</h1>
<p>The abstract operation ForIn/OfBodyEvaluation takes arguments <var>lhs</var> (a <emu-xref href="#sec-syntactic-grammar" id="_ref_7251"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>), <var>stmt</var> (a <emu-nt id="_ref_21919"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7252"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>), <var>iteratorRecord</var> (an <emu-xref href="#sec-iterator-records" id="_ref_7253"><a href="abstract-operations.html#sec-iterator-records">Iterator Record</a></emu-xref>), <var>iterationKind</var> (<emu-const>enumerate</emu-const> or <emu-const>iterate</emu-const>), <var>lhsKind</var> (<emu-const>assignment</emu-const>, <emu-const>var-binding</emu-const>, or <emu-const>lexical-binding</emu-const>), and <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7254"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and optional argument <var>iteratorKind</var> (<emu-const>sync</emu-const> or <emu-const>async</emu-const>) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7255"><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_7256"><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_7257"><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>iteratorKind</var> is not present, set <var>iteratorKind</var> to <emu-const>sync</emu-const>.</li><li>Let <var>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7258"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>V</var> be <emu-val>undefined</emu-val>.</li><li>Let <var>destructuring</var> be <emu-xref aoid="IsDestructuring" id="_ref_7259"><a href="ecmascript-language-statements-and-declarations.html#sec-static-semantics-isdestructuring">IsDestructuring</a></emu-xref> of <var>lhs</var>.</li><li>If <var>destructuring</var> is <emu-val>true</emu-val> and <var>lhsKind</var> is <emu-const>assignment</emu-const>, then<ol><li><emu-xref href="#assert" id="_ref_7260"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>lhs</var> is a <emu-nt id="_ref_21920"><a href="ecmascript-language-expressions.html#prod-LeftHandSideExpression">LeftHandSideExpression</a></emu-nt>.</li><li>Let <var>assignmentPattern</var> be the <emu-nt id="_ref_21921"><a href="ecmascript-language-expressions.html#prod-AssignmentPattern">AssignmentPattern</a></emu-nt> that is <emu-xref href="#sec-syntactic-grammar" id="_ref_7261"><a href="notational-conventions.html#sec-syntactic-grammar">covered</a></emu-xref> by <var>lhs</var>.</li></ol></li><li>Repeat,<ol><li>Let <var>nextResult</var> be ?&nbsp;<emu-xref aoid="Call" id="_ref_7262"><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><li>If <var>iteratorKind</var> is <emu-const>async</emu-const>, set <var>nextResult</var> to ?&nbsp;<emu-xref aoid="Await" id="_ref_7263"><a href="control-abstraction-objects.html#await" class="e-user-code">Await</a></emu-xref>(<var>nextResult</var>).</li><li>If <var>nextResult</var> <emu-xref href="#sec-object-type" id="_ref_7264"><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>done</var> be ?&nbsp;<emu-xref aoid="IteratorComplete" id="_ref_7265"><a href="abstract-operations.html#sec-iteratorcomplete" class="e-user-code">IteratorComplete</a></emu-xref>(<var>nextResult</var>).</li><li>If <var>done</var> is <emu-val>true</emu-val>, return <var>V</var>.</li><li>Let <var>nextValue</var> be ?&nbsp;<emu-xref aoid="IteratorValue" id="_ref_7266"><a href="abstract-operations.html#sec-iteratorvalue" class="e-user-code">IteratorValue</a></emu-xref>(<var>nextResult</var>).</li><li>If <var>lhsKind</var> is either <emu-const>assignment</emu-const> or <emu-const>var-binding</emu-const>, then<ol><li>If <var>destructuring</var> is <emu-val>true</emu-val>, then<ol><li>If <var>lhsKind</var> is <emu-const>assignment</emu-const>, then<ol><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_7267"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="DestructuringAssignmentEvaluation" id="_ref_7268"><a href="ecmascript-language-expressions.html#sec-runtime-semantics-destructuringassignmentevaluation" class="e-user-code">DestructuringAssignmentEvaluation</a></emu-xref> of <var>assignmentPattern</var> with argument <var>nextValue</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_7269"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>lhsKind</var> is <emu-const>var-binding</emu-const>.</li><li><emu-xref href="#assert" id="_ref_7270"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>lhs</var> is a <emu-nt id="_ref_21922"><a href="ecmascript-language-statements-and-declarations.html#prod-ForBinding">ForBinding</a></emu-nt>.</li><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_7271"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="BindingInitialization" id="_ref_7272"><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" class="e-user-code">BindingInitialization</a></emu-xref> of <var>lhs</var> with arguments <var>nextValue</var> and <emu-val>undefined</emu-val>).</li></ol></li></ol></li><li>Else,<ol><li>Let <var>lhsRef</var> be <emu-xref aoid="Completion" id="_ref_7273"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7274"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>lhs</var>). (It may be evaluated repeatedly.)</li><li>If <var>lhsKind</var> is <emu-const>assignment</emu-const> and the <emu-xref aoid="AssignmentTargetType" id="_ref_7275"><a href="syntax-directed-operations.html#sec-static-semantics-assignmenttargettype">AssignmentTargetType</a></emu-xref> of <var>lhs</var> is <emu-const>web-compat</emu-const>, throw a <emu-val>ReferenceError</emu-val> exception.</li><li>If <var>lhsRef</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7276"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Let <var>status</var> be <var>lhsRef</var>.</li></ol></li><li>Else,<ol><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_7277"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="PutValue" id="_ref_7278"><a href="ecmascript-data-types-and-values.html#sec-putvalue" class="e-user-code">PutValue</a></emu-xref>(<var>lhsRef</var>.<var class="field">[[Value]]</var>, <var>nextValue</var>)).</li></ol></li></ol></li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_7279"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>lhsKind</var> is <emu-const>lexical-binding</emu-const>.</li><li><emu-xref href="#assert" id="_ref_7280"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>lhs</var> is a <emu-nt id="_ref_21923"><a href="ecmascript-language-statements-and-declarations.html#prod-ForDeclaration">ForDeclaration</a></emu-nt>.</li><li>Let <var>iterationEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_7281"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>oldEnv</var>).</li><li>Perform <emu-xref aoid="ForDeclarationBindingInstantiation" id="_ref_7282"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-fordeclarationbindinginstantiation">ForDeclarationBindingInstantiation</a></emu-xref> of <var>lhs</var> with argument <var>iterationEnv</var>.</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7283"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>iterationEnv</var>.</li><li>If <var>destructuring</var> is <emu-val>true</emu-val>, then<ol><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_7284"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="ForDeclarationBindingInitialization" id="_ref_7285"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-fordeclarationbindinginitialization" class="e-user-code">ForDeclarationBindingInitialization</a></emu-xref> of <var>lhs</var> with arguments <var>nextValue</var> and <var>iterationEnv</var>).</li></ol></li><li>Else,<ol><li><emu-xref href="#assert" id="_ref_7286"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>lhs</var> binds a single name.</li><li>Let <var>lhsName</var> be the sole element of the <emu-xref aoid="BoundNames" id="_ref_7287"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <var>lhs</var>.</li><li>Let <var>lhsRef</var> be !&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_7288"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding">ResolveBinding</a></emu-xref>(<var>lhsName</var>).</li><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_7289"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="InitializeReferencedBinding" id="_ref_7290"><a href="ecmascript-data-types-and-values.html#sec-initializereferencedbinding">InitializeReferencedBinding</a></emu-xref>(<var>lhsRef</var>, <var>nextValue</var>)).</li></ol></li></ol></li><li>If <var>status</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7291"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Set the <emu-xref href="#running-execution-context" id="_ref_7292"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>If <var>iterationKind</var> is <emu-const>enumerate</emu-const>, return ?&nbsp;<var>status</var>.</li><li><emu-xref href="#assert" id="_ref_7293"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>iterationKind</var> is <emu-const>iterate</emu-const>.</li><li>If <var>iteratorKind</var> is <emu-const>async</emu-const>, return ?&nbsp;<emu-xref aoid="AsyncIteratorClose" id="_ref_7294"><a href="abstract-operations.html#sec-asynciteratorclose" class="e-user-code">AsyncIteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>status</var>).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_7295"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>status</var>).</li></ol></li><li>Let <var>result</var> be <emu-xref aoid="Completion" id="_ref_7296"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7297"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>stmt</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7298"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>If <emu-xref aoid="LoopContinues" id="_ref_7299"><a href="ecmascript-language-statements-and-declarations.html#sec-loopcontinues">LoopContinues</a></emu-xref>(<var>result</var>, <var>labelSet</var>) is <emu-val>false</emu-val>, then<ol><li>Set <var>status</var> to <emu-xref aoid="Completion" id="_ref_7300"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="UpdateEmpty" id="_ref_7301"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>result</var>, <var>V</var>)).</li><li>If <var>iterationKind</var> is <emu-const>enumerate</emu-const>, return ?&nbsp;<var>status</var>.</li><li><emu-xref href="#assert" id="_ref_7302"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>iterationKind</var> is <emu-const>iterate</emu-const>.</li><li>If <var>iteratorKind</var> is <emu-const>async</emu-const>, return ?&nbsp;<emu-xref aoid="AsyncIteratorClose" id="_ref_7303"><a href="abstract-operations.html#sec-asynciteratorclose" class="e-user-code">AsyncIteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>status</var>).</li><li>Return ?&nbsp;<emu-xref aoid="IteratorClose" id="_ref_7304"><a href="abstract-operations.html#sec-iteratorclose" class="e-user-code">IteratorClose</a></emu-xref>(<var>iteratorRecord</var>, <var>status</var>).</li></ol></li><li>If <var>result</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>result</var>.<var class="field">[[Value]]</var>.</li></ol></li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-for-in-and-for-of-statements-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.7.5.8</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="BindingIdentifier">
<emu-nt><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="bras6mo_" id="prod-_anR-waH">
<emu-nt id="_ref_21924"><a href="ecmascript-language-expressions.html#prod-Identifier">Identifier</a></emu-nt>
</emu-rhs>
<emu-rhs a="0d8zyjn8" id="prod-K8Yvyf4p">
<emu-t>yield</emu-t>
</emu-rhs>
<emu-rhs a="hx1dvlrw" id="prod-KzQjZu5p">
<emu-t>await</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>bindingId</var> be the <emu-xref aoid="StringValue" id="_ref_7305"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21925"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt>.</li><li>Return ?&nbsp;<emu-xref aoid="ResolveBinding" id="_ref_7306"><a href="executable-code-and-execution-contexts.html#sec-resolvebinding" class="e-user-code">ResolveBinding</a></emu-xref>(<var>bindingId</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-enumerate-object-properties" type="abstract operation" aoid="EnumerateObjectProperties">
<h1><span class="secnum">14.7.5.9</span> EnumerateObjectProperties ( <var>O</var> )</h1>
<p>The abstract operation EnumerateObjectProperties takes argument <var>O</var> (an Object) and returns an <emu-xref href="#sec-iterator-interface" id="_ref_7307"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref>. It performs the following steps when called:</p>
<emu-alg><ol><li>Return an <emu-xref href="#sec-iterator-interface" id="_ref_7308"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref> whose <code>next</code> method iterates over all the String-valued keys of enumerable properties of <var>O</var>. The <emu-xref href="#sec-iterator-interface" id="_ref_7309"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator object</a></emu-xref> is never directly accessible to ECMAScript code. The mechanics and order of enumerating the properties is not specified but must conform to the rules specified below.</li></ol></emu-alg>
<p>The <emu-xref href="#sec-iterator-interface" id="_ref_7310"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>'s <code>throw</code> and <code>return</code> methods are <emu-val>null</emu-val> and are never invoked. The <emu-xref href="#sec-iterator-interface" id="_ref_7311"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>'s <code>next</code> method processes object properties to determine whether the <emu-xref href="#property-key" id="_ref_7312"><a href="ecmascript-data-types-and-values.html#property-key">property key</a></emu-xref> should be returned as an <emu-xref href="#sec-iterator-interface" id="_ref_7313"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> value. Returned <emu-xref href="#property-key" id="_ref_7314"><a href="ecmascript-data-types-and-values.html#property-key">property keys</a></emu-xref> do not include keys that are Symbols. Properties of the target object may be deleted during enumeration. A property that is deleted before it is processed by the <emu-xref href="#sec-iterator-interface" id="_ref_7315"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>'s <code>next</code> method is ignored. If new properties are added to the target object during enumeration, the newly added properties are not guaranteed to be processed in the active enumeration. A <emu-xref href="#property-name" id="_ref_7316"><a href="ecmascript-data-types-and-values.html#property-name">property name</a></emu-xref> will be returned by the <emu-xref href="#sec-iterator-interface" id="_ref_7317"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>'s <code>next</code> method at most once in any enumeration.</p>
<p>Enumerating the properties of the target object includes enumerating properties of its prototype, and the prototype of the prototype, and so on, recursively; but a property of a prototype is not processed if it has the same name as a property that has already been processed by the <emu-xref href="#sec-iterator-interface" id="_ref_7318"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref>'s <code>next</code> method. The values of <var class="field">[[Enumerable]]</var> attributes are not considered when determining if a property of a prototype object has already been processed. The enumerable <emu-xref href="#property-name" id="_ref_7319"><a href="ecmascript-data-types-and-values.html#property-name">property names</a></emu-xref> of prototype objects must be obtained by invoking EnumerateObjectProperties passing the prototype object as the argument. EnumerateObjectProperties must obtain the own <emu-xref href="#property-key" id="_ref_7320"><a href="ecmascript-data-types-and-values.html#property-key">property keys</a></emu-xref> of the target object by calling its <var class="field">[[OwnPropertyKeys]]</var> internal method. Property attributes of the target object must be obtained by calling its <var class="field">[[GetOwnProperty]]</var> internal method.</p>
<p>In addition, if neither <var>O</var> nor any object in its prototype chain is a <emu-xref href="#proxy-exotic-object" id="_ref_7321"><a href="ordinary-and-exotic-objects-behaviours.html#proxy-exotic-object">Proxy exotic object</a></emu-xref>, <emu-xref href="#typedarray" id="_ref_7322"><a href="ordinary-and-exotic-objects-behaviours.html#typedarray">TypedArray</a></emu-xref>, <emu-xref href="#module-namespace-exotic-object" id="_ref_7323"><a href="ordinary-and-exotic-objects-behaviours.html#module-namespace-exotic-object">module namespace exotic object</a></emu-xref>, or implementation provided <emu-xref href="#exotic-object" id="_ref_7324"><a href="ecmascript-data-types-and-values.html#exotic-object">exotic object</a></emu-xref>, then the <emu-xref href="#sec-iterator-interface" id="_ref_7325"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> must behave as would the <emu-xref href="#sec-iterator-interface" id="_ref_7326"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> given by <emu-xref aoid="CreateForInIterator" id="_ref_7327"><a href="ecmascript-language-statements-and-declarations.html#sec-createforiniterator">CreateForInIterator</a></emu-xref>(<var>O</var>) until one of the following occurs:</p>
<ul>
<li>the value of the <var class="field">[[Prototype]]</var> internal slot of <var>O</var> or an object in its prototype chain changes,</li>
<li>a property is removed from <var>O</var> or an object in its prototype chain,</li>
<li>a property is added to an object in <var>O</var>'s prototype chain, or</li>
<li>the value of the <var class="field">[[Enumerable]]</var> attribute of a property of <var>O</var> or an object in its prototype chain changes.</li>
</ul>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>ECMAScript implementations are not required to implement the algorithm in <emu-xref href="#sec-%foriniteratorprototype%.next" id="_ref_453"><a href="ecmascript-language-statements-and-declarations.html#sec-%foriniteratorprototype%.next">14.7.5.10.2.1</a></emu-xref> directly. They may choose any implementation whose behaviour will not deviate from that algorithm unless one of the constraints in the previous paragraph is violated.</p>
<p>The following is an informative definition of an ECMAScript generator function that conforms to these rules:</p>
<pre><code class="javascript hljs"><span class="hljs-keyword">function</span>* <span class="hljs-title class_">EnumerateObjectProperties</span>(obj) {
<span class="hljs-keyword">const</span> visited = <span class="hljs-keyword">new</span> <span class="hljs-title class_">Set</span>();
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">const</span> key <span class="hljs-keyword">of</span> <span class="hljs-title class_">Reflect</span>.<span class="hljs-title function_">ownKeys</span>(obj)) {
<span class="hljs-keyword">if</span> (<span class="hljs-keyword">typeof</span> key === <span class="hljs-string">"symbol"</span>) <span class="hljs-keyword">continue</span>;
<span class="hljs-keyword">const</span> desc = <span class="hljs-title class_">Reflect</span>.<span class="hljs-title function_">getOwnPropertyDescriptor</span>(obj, key);
<span class="hljs-keyword">if</span> (desc) {
visited.<span class="hljs-title function_">add</span>(key);
<span class="hljs-keyword">if</span> (desc.<span class="hljs-property">enumerable</span>) <span class="hljs-keyword">yield</span> key;
}
}
<span class="hljs-keyword">const</span> proto = <span class="hljs-title class_">Reflect</span>.<span class="hljs-title function_">getPrototypeOf</span>(obj);
<span class="hljs-keyword">if</span> (proto === <span class="hljs-literal">null</span>) <span class="hljs-keyword">return</span>;
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">const</span> protoKey <span class="hljs-keyword">of</span> <span class="hljs-title class_">EnumerateObjectProperties</span>(proto)) {
<span class="hljs-keyword">if</span> (!visited.<span class="hljs-title function_">has</span>(protoKey)) <span class="hljs-keyword">yield</span> protoKey;
}
}</code></pre>
</div></emu-note>
<emu-note><span class="note">Note 2</span><div class="note-contents">
The list of <emu-xref href="#exotic-object" id="_ref_7328"><a href="ecmascript-data-types-and-values.html#exotic-object">exotic objects</a></emu-xref> for which implementations are not required to match <emu-xref aoid="CreateForInIterator" id="_ref_7329"><a href="ecmascript-language-statements-and-declarations.html#sec-createforiniterator">CreateForInIterator</a></emu-xref> was chosen because implementations historically differed in behaviour for those cases, and agreed in all others.
</div></emu-note>
</emu-clause>
<emu-clause id="sec-for-in-iterator-objects">
<h1><span class="secnum">14.7.5.10</span> For-In Iterator Objects</h1>
<p>A <dfn variants="For-In Iterator object,For-In Iterator objects" tabindex="-1">For-In Iterator</dfn> is an object that represents a specific iteration over some specific object. For-In Iterator objects are never directly accessible to ECMAScript code; they exist solely to illustrate the behaviour of <emu-xref aoid="EnumerateObjectProperties" id="_ref_7330"><a href="ecmascript-language-statements-and-declarations.html#sec-enumerate-object-properties">EnumerateObjectProperties</a></emu-xref>.</p>
<emu-clause id="sec-createforiniterator" type="abstract operation" aoid="CreateForInIterator">
<h1><span class="secnum">14.7.5.10.1</span> CreateForInIterator ( <var>object</var> )</h1>
<p>The abstract operation CreateForInIterator takes argument <var>object</var> (an Object) and returns a <emu-xref href="#sec-for-in-iterator-objects" id="_ref_7331"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In Iterator</a></emu-xref>. It is used to create a <emu-xref href="#sec-for-in-iterator-objects" id="_ref_7332"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In Iterator object</a></emu-xref> which iterates over the own and inherited enumerable string properties of <var>object</var> in a specific order. It performs the following steps when called:</p>
<emu-alg><ol><li>Let <var>iterator</var> be <emu-xref aoid="OrdinaryObjectCreate" id="_ref_7333"><a href="ordinary-and-exotic-objects-behaviours.html#sec-ordinaryobjectcreate">OrdinaryObjectCreate</a></emu-xref>(<emu-xref href="#sec-%foriniteratorprototype%-object" id="_ref_7334"><a href="ecmascript-language-statements-and-declarations.html#sec-%foriniteratorprototype%-object">%ForInIteratorPrototype%</a></emu-xref>, « <var class="field">[[Object]]</var>, <var class="field">[[ObjectWasVisited]]</var>, <var class="field">[[VisitedKeys]]</var>, <var class="field">[[RemainingKeys]]</var>&nbsp;»).</li><li>Set <var>iterator</var>.<var class="field">[[Object]]</var> to <var>object</var>.</li><li>Set <var>iterator</var>.<var class="field">[[ObjectWasVisited]]</var> to <emu-val>false</emu-val>.</li><li>Set <var>iterator</var>.<var class="field">[[VisitedKeys]]</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7335"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Set <var>iterator</var>.<var class="field">[[RemainingKeys]]</var> to a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7336"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li><li>Return <var>iterator</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-%foriniteratorprototype%-object">
<h1><span class="secnum">14.7.5.10.2</span> The %ForInIteratorPrototype% Object</h1>
<p>The <dfn tabindex="-1">%ForInIteratorPrototype%</dfn> object:</p>
<ul>
<li>has properties that are inherited by all <emu-xref href="#sec-for-in-iterator-objects" id="_ref_7337"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In Iterator objects</a></emu-xref>.</li>
<li>is an <emu-xref href="#ordinary-object" id="_ref_7338"><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_7339"><a href="control-abstraction-objects.html#sec-%iterator.prototype%-object">%Iterator.prototype%</a></emu-xref>.</li>
<li>is never directly accessible to ECMAScript code.</li>
<li>has the following properties:</li>
</ul>
<emu-clause id="sec-%foriniteratorprototype%.next" type="built-in function">
<h1><span class="secnum">14.7.5.10.2.1</span> %ForInIteratorPrototype%.next ( )</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_7340"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>O</var> <emu-xref href="#sec-object-type" id="_ref_7341"><a href="ecmascript-data-types-and-values.html#sec-object-type">is an Object</a></emu-xref>.</li><li><emu-xref href="#assert" id="_ref_7342"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>O</var> has all of the internal slots of a <emu-xref href="#sec-for-in-iterator-objects" id="_ref_7343"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In Iterator</a></emu-xref> instance (<emu-xref href="#sec-properties-of-for-in-iterator-instances" id="_ref_454"><a href="ecmascript-language-statements-and-declarations.html#sec-properties-of-for-in-iterator-instances">14.7.5.10.3</a></emu-xref>).</li><li>Let <var>object</var> be <var>O</var>.<var class="field">[[Object]]</var>.</li><li>Repeat,<ol><li>If <var>O</var>.<var class="field">[[ObjectWasVisited]]</var> is <emu-val>false</emu-val>, then<ol><li>Let <var>keys</var> be ?&nbsp;<span class="e-user-code"><var>object</var>.<var class="field">[[OwnPropertyKeys]]</var>()</span>.</li><li>For each element <var>key</var> of <var>keys</var>, do<ol><li>If <var>key</var> <emu-xref href="#sec-ecmascript-language-types-string-type" id="_ref_7344"><a href="ecmascript-data-types-and-values.html#sec-ecmascript-language-types-string-type">is a String</a></emu-xref>, then<ol><li>Append <var>key</var> to <var>O</var>.<var class="field">[[RemainingKeys]]</var>.</li></ol></li></ol></li><li>Set <var>O</var>.<var class="field">[[ObjectWasVisited]]</var> to <emu-val>true</emu-val>.</li></ol></li><li>Repeat, while <var>O</var>.<var class="field">[[RemainingKeys]]</var> is not empty,<ol><li>Let <var>r</var> be the first element of <var>O</var>.<var class="field">[[RemainingKeys]]</var>.</li><li>Remove the first element from <var>O</var>.<var class="field">[[RemainingKeys]]</var>.</li><li>If <var>O</var>.<var class="field">[[VisitedKeys]]</var> does not contain <var>r</var>, then<ol><li>Let <var>desc</var> be ?&nbsp;<span class="e-user-code"><var>object</var>.<var class="field">[[GetOwnProperty]]</var>(<var>r</var>)</span>.</li><li>If <var>desc</var> is not <emu-val>undefined</emu-val>, then<ol><li>Append <var>r</var> to <var>O</var>.<var class="field">[[VisitedKeys]]</var>.</li><li>If <var>desc</var>.<var class="field">[[Enumerable]]</var> is <emu-val>true</emu-val>, return <emu-xref aoid="CreateIteratorResultObject" id="_ref_7345"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<var>r</var>, <emu-val>false</emu-val>).</li></ol></li></ol></li></ol></li><li>Set <var>object</var> to ?&nbsp;<span class="e-user-code"><var>object</var>.<var class="field">[[GetPrototypeOf]]</var>()</span>.</li><li>Set <var>O</var>.<var class="field">[[Object]]</var> to <var>object</var>.</li><li>Set <var>O</var>.<var class="field">[[ObjectWasVisited]]</var> to <emu-val>false</emu-val>.</li><li>If <var>object</var> is <emu-val>null</emu-val>, return <emu-xref aoid="CreateIteratorResultObject" id="_ref_7346"><a href="abstract-operations.html#sec-createiterresultobject">CreateIteratorResultObject</a></emu-xref>(<emu-val>undefined</emu-val>, <emu-val>true</emu-val>).</li></ol></li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-properties-of-for-in-iterator-instances">
<h1><span class="secnum">14.7.5.10.3</span> Properties of For-In Iterator Instances</h1>
<p><emu-xref href="#sec-for-in-iterator-objects" id="_ref_7347"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In Iterator</a></emu-xref> instances are <emu-xref href="#ordinary-object" id="_ref_7348"><a href="ecmascript-data-types-and-values.html#ordinary-object">ordinary objects</a></emu-xref> that inherit properties from the <emu-xref href="#sec-%foriniteratorprototype%-object" id="_ref_7349"><a href="ecmascript-language-statements-and-declarations.html#sec-%foriniteratorprototype%-object">%ForInIteratorPrototype%</a></emu-xref> intrinsic object. <emu-xref href="#sec-for-in-iterator-objects" id="_ref_7350"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In Iterator</a></emu-xref> instances are initially created with the internal slots listed in <emu-xref href="#table-for-in-iterator-instance-slots" id="_ref_455"><a href="ecmascript-language-statements-and-declarations.html#table-for-in-iterator-instance-slots">Table 33</a></emu-xref>.</p>
<emu-table id="table-for-in-iterator-instance-slots" caption="Internal Slots of For-In Iterator Instances"><figure><figcaption>Table 33: Internal Slots of <emu-xref href="#sec-for-in-iterator-objects" id="_ref_7351"><a href="ecmascript-language-statements-and-declarations.html#sec-for-in-iterator-objects">For-In 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">[[Object]]</var>
</td>
<td>
an Object
</td>
<td>
The Object value whose properties are being iterated.
</td>
</tr>
<tr>
<td>
<var class="field">[[ObjectWasVisited]]</var>
</td>
<td>
a Boolean
</td>
<td>
<emu-val>true</emu-val> if the <emu-xref href="#sec-iterator-interface" id="_ref_7352"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> has invoked <var class="field">[[OwnPropertyKeys]]</var> on <var class="field">[[Object]]</var>, <emu-val>false</emu-val> otherwise.
</td>
</tr>
<tr>
<td>
<var class="field">[[VisitedKeys]]</var>
</td>
<td>
a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7353"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings
</td>
<td>
The values that have been emitted by this <emu-xref href="#sec-iterator-interface" id="_ref_7354"><a href="control-abstraction-objects.html#sec-iterator-interface">iterator</a></emu-xref> thus far.
</td>
</tr>
<tr>
<td>
<var class="field">[[RemainingKeys]]</var>
</td>
<td>
a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7355"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings
</td>
<td>
The values remaining to be emitted for the current object, before iterating the properties of its prototype (if its prototype is not <emu-val>null</emu-val>).
</td>
</tr>
</tbody></table>
</figure></emu-table>
</emu-clause>
</emu-clause>
</emu-clause>
</emu-clause>
<emu-clause id="sec-continue-statement">
<h1><span class="secnum">14.8</span> The <code>continue</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="ContinueStatement" params="Yield, Await" id="prod-ContinueStatement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="6qppgxyk" id="prod-rfM2mnQY">
<emu-t>continue</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
<emu-rhs a="fiwlh1nt" id="prod-w6m19zWs">
<emu-t>continue</emu-t>
<emu-gann>[no <emu-nt id="_ref_21926"><a href="ecmascript-language-lexical-grammar.html#prod-LineTerminator">LineTerminator</a></emu-nt> here]</emu-gann>
<emu-nt params="?Yield, ?Await" id="_ref_21927"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-continue-statement-static-semantics-early-errors">
<h1><span class="secnum">14.8.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="ContinueStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="6qppgxyk">
<emu-t>continue</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
<emu-rhs a="wh7qddgu">
<emu-t>continue</emu-t>
<emu-nt id="_ref_21928"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if this <emu-nt id="_ref_21929"><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a></emu-nt> is not nested, directly or indirectly (but not crossing function or <code>static</code> initialization block boundaries), within an <emu-nt id="_ref_21930"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-continue-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.8.2</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="ContinueStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="6qppgxyk" id="prod-MdaDQGie">
<emu-t>continue</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-xref href="#sec-completion-record-specification-type" id="_ref_7356"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> { <var class="field">[[Type]]</var>: <emu-const>continue</emu-const>, <var class="field">[[Value]]</var>: <emu-const>empty</emu-const>, <var class="field">[[Target]]</var>: <emu-const>empty</emu-const>&nbsp;}.</li></ol></emu-alg>
<emu-grammar><emu-production name="ContinueStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="wh7qddgu" id="prod-sLmRG5Rx">
<emu-t>continue</emu-t>
<emu-nt id="_ref_21931"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>label</var> be the <emu-xref aoid="StringValue" id="_ref_7357"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21932"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>.</li><li>Return <emu-xref href="#sec-completion-record-specification-type" id="_ref_7358"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> { <var class="field">[[Type]]</var>: <emu-const>continue</emu-const>, <var class="field">[[Value]]</var>: <emu-const>empty</emu-const>, <var class="field">[[Target]]</var>: <var>label</var>&nbsp;}.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-break-statement">
<h1><span class="secnum">14.9</span> The <code>break</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="BreakStatement" params="Yield, Await" id="prod-BreakStatement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="tlip5zkt" id="prod-Jyx4vreG">
<emu-t>break</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
<emu-rhs a="nio0l2c9" id="prod-_aoH2Ltk">
<emu-t>break</emu-t>
<emu-gann>[no <emu-nt id="_ref_21933"><a href="ecmascript-language-lexical-grammar.html#prod-LineTerminator">LineTerminator</a></emu-nt> here]</emu-gann>
<emu-nt params="?Yield, ?Await" id="_ref_21934"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-break-statement-static-semantics-early-errors">
<h1><span class="secnum">14.9.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="BreakStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="tlip5zkt">
<emu-t>break</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if this <emu-nt id="_ref_21935"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a></emu-nt> is not nested, directly or indirectly (but not crossing function or <code>static</code> initialization block boundaries), within an <emu-nt id="_ref_21936"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> or a <emu-nt id="_ref_21937"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-break-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.9.2</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="BreakStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="tlip5zkt" id="prod-0ioO2qvc">
<emu-t>break</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-xref href="#sec-completion-record-specification-type" id="_ref_7359"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> { <var class="field">[[Type]]</var>: <emu-const>break</emu-const>, <var class="field">[[Value]]</var>: <emu-const>empty</emu-const>, <var class="field">[[Target]]</var>: <emu-const>empty</emu-const>&nbsp;}.</li></ol></emu-alg>
<emu-grammar><emu-production name="BreakStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="kcg-yy3r" id="prod-eokV1qEw">
<emu-t>break</emu-t>
<emu-nt id="_ref_21938"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>label</var> be the <emu-xref aoid="StringValue" id="_ref_7360"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_21939"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>.</li><li>Return <emu-xref href="#sec-completion-record-specification-type" id="_ref_7361"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> { <var class="field">[[Type]]</var>: <emu-const>break</emu-const>, <var class="field">[[Value]]</var>: <emu-const>empty</emu-const>, <var class="field">[[Target]]</var>: <var>label</var>&nbsp;}.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-return-statement">
<h1><span class="secnum">14.10</span> The <code>return</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="ReturnStatement" params="Yield, Await" id="prod-ReturnStatement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ReturnStatement">ReturnStatement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="cykzgrgr" id="prod-zZYaGxQ8">
<emu-t>return</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
<emu-rhs a="tybfdyhl" id="prod-TbDZIC37">
<emu-t>return</emu-t>
<emu-gann>[no <emu-nt id="_ref_21940"><a href="ecmascript-language-lexical-grammar.html#prod-LineTerminator">LineTerminator</a></emu-nt> here]</emu-gann>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21941"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>A <code>return</code> statement causes a function to cease execution and, in most cases, returns a value to the caller. If <emu-nt id="_ref_21942"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> is omitted, the return value is <emu-val>undefined</emu-val>. Otherwise, the return value is the value of <emu-nt id="_ref_21943"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>. A <code>return</code> statement may not actually return a value to the caller depending on surrounding context. For example, in a <code>try</code> block, a <code>return</code> statement's <emu-xref href="#sec-completion-record-specification-type" id="_ref_7362"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> may be replaced with another <emu-xref href="#sec-completion-record-specification-type" id="_ref_7363"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref> during evaluation of the <code>finally</code> block.</p>
</div></emu-note>
<emu-clause id="sec-return-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.10.1</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="ReturnStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ReturnStatement">ReturnStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="cykzgrgr" id="prod-G_yzzAkQ">
<emu-t>return</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-xref aoid="ReturnCompletion" id="_ref_7364"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li></ol></emu-alg>
<emu-grammar><emu-production name="ReturnStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ReturnStatement">ReturnStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="tpdzx2lh" id="prod-iroo5DiR">
<emu-t>return</emu-t>
<emu-nt id="_ref_21944"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7365"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21945"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>exprValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7366"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li><li>If <emu-xref aoid="GetGeneratorKind" id="_ref_7367"><a href="control-abstraction-objects.html#sec-getgeneratorkind">GetGeneratorKind</a></emu-xref>() is <emu-const>async</emu-const>, set <var>exprValue</var> to ?&nbsp;<emu-xref aoid="Await" id="_ref_7368"><a href="control-abstraction-objects.html#await" class="e-user-code">Await</a></emu-xref>(<var>exprValue</var>).</li><li>Return <emu-xref aoid="ReturnCompletion" id="_ref_7369"><a href="ecmascript-data-types-and-values.html#sec-returncompletion">ReturnCompletion</a></emu-xref>(<var>exprValue</var>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-with-statement" legacy=""><div class="attributes-tag"><emu-xref href="#sec-conformance" id="_ref_7388"><a href="conformance.html#sec-conformance">Legacy</a></emu-xref></div>
<h1><span class="secnum">14.11</span> The <code>with</code> Statement</h1>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>Use of the <emu-xref href="#sec-conformance" id="_ref_7370"><a href="conformance.html#sec-conformance">Legacy</a></emu-xref> <code>with</code> statement is discouraged in new ECMAScript code. Consider alternatives that are permitted in both <emu-xref href="#sec-strict-mode-code" id="_ref_7371"><a href="ecmascript-language-source-code.html#sec-strict-mode-code">strict mode code</a></emu-xref> and <emu-xref href="#non-strict-code" id="_ref_7372"><a href="ecmascript-language-source-code.html#non-strict-code">non-strict code</a></emu-xref>, such as <emu-xref href="#sec-destructuring-assignment" id="_ref_456"><a href="ecmascript-language-expressions.html#sec-destructuring-assignment">destructuring assignment</a></emu-xref>.</p>
</div></emu-note>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="WithStatement" params="Yield, Await, Return" id="prod-WithStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-WithStatement">WithStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="lo7bccts" id="prod-3HlNX-pI">
<emu-t>with</emu-t>
<emu-t>(</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21946"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21947"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>The <code>with</code> statement adds an <emu-xref href="#sec-object-environment-records" id="_ref_7373"><a href="executable-code-and-execution-contexts.html#sec-object-environment-records">Object Environment Record</a></emu-xref> for a computed object to the lexical environment of the <emu-xref href="#running-execution-context" id="_ref_7374"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>. It then executes a statement using this augmented lexical environment. Finally, it restores the original lexical environment.</p>
</div></emu-note>
<emu-clause id="sec-with-statement-static-semantics-early-errors">
<h1><span class="secnum">14.11.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="WithStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-WithStatement">WithStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="i70kview">
<emu-t>with</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21948"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21949"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if <emu-xref aoid="IsStrict" id="_ref_7375"><a href="ecmascript-language-source-code.html#sec-isstrict">IsStrict</a></emu-xref>(this production) is <emu-val>true</emu-val>.
</li>
<li>
It is a Syntax Error if <emu-xref aoid="IsLabelledFunction" id="_ref_7376"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<emu-nt id="_ref_21950"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>) is <emu-val>true</emu-val>.
</li>
</ul>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>It is only necessary to apply the second rule if the extension specified in <emu-xref href="#sec-labelled-function-declarations" id="_ref_457"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">B.3.1</a></emu-xref> is implemented.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-with-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.11.2</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="WithStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-WithStatement">WithStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="i70kview" id="prod-OowrNhmq">
<emu-t>with</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21951"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21952"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>val</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7377"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21953"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>obj</var> be ?&nbsp;<emu-xref aoid="ToObject" id="_ref_7378"><a href="abstract-operations.html#sec-toobject">ToObject</a></emu-xref>(? <emu-xref aoid="GetValue" id="_ref_7379"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>val</var>)).</li><li>Let <var>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7380"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>newEnv</var> be <emu-xref aoid="NewObjectEnvironment" id="_ref_7381"><a href="executable-code-and-execution-contexts.html#sec-newobjectenvironment">NewObjectEnvironment</a></emu-xref>(<var>obj</var>, <emu-val>true</emu-val>, <var>oldEnv</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7382"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>newEnv</var>.</li><li>Let <var>C</var> be <emu-xref aoid="Completion" id="_ref_7383"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7384"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21954"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7385"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7386"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>C</var>, <emu-val>undefined</emu-val>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>No matter how control leaves the embedded <emu-nt id="_ref_21955"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>, whether normally or by some form of <emu-xref href="#sec-completion-record-specification-type" id="_ref_7387"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref> or exception, the LexicalEnvironment is always restored to its former state.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-switch-statement">
<h1><span class="secnum">14.12</span> The <code>switch</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="SwitchStatement" params="Yield, Await, Return" id="prod-SwitchStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="drlywp4w" id="prod-3xRnqKfC">
<emu-t>switch</emu-t>
<emu-t>(</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21956"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21957"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="CaseBlock" params="Yield, Await, Return" id="prod-CaseBlock">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="v-h2atfk" id="prod-q66ZlOHI">
<emu-t>{</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" optional="" id="_ref_21958"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
<emu-rhs a="00sitdqr" id="prod-JuWwIrcZ">
<emu-t>{</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" optional="" id="_ref_21959"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21960"><a href="ecmascript-language-statements-and-declarations.html#prod-DefaultClause">DefaultClause</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" optional="" id="_ref_21961"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
<emu-production name="CaseClauses" params="Yield, Await, Return" id="prod-CaseClauses">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="xpjvtgza">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21962"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="8r6dchoz" id="prod-sjZo1Z65">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21963"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_21964"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="CaseClause" params="Yield, Await, Return" id="prod-CaseClause">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="zpq23qtn" id="prod-A-5Q_6I5">
<emu-t>case</emu-t>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_21965"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>:</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" optional="" id="_ref_21966"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="DefaultClause" params="Yield, Await, Return" id="prod-DefaultClause">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-DefaultClause">DefaultClause</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="djnlaxcj" id="prod-HPF3iA_C">
<emu-t>default</emu-t>
<emu-t>:</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" optional="" id="_ref_21967"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-switch-statement-static-semantics-early-errors" oldids="sec-switch-duplicates-allowed-static-semantics"><span id="sec-switch-duplicates-allowed-static-semantics"></span>
<h1><span class="secnum">14.12.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="SwitchStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uvrp_hkw">
<emu-t>switch</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_21968"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_21969"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
<p>It is a Syntax Error if the <emu-xref aoid="LexicallyDeclaredNames" id="_ref_7389"><a href="syntax-directed-operations.html#sec-static-semantics-lexicallydeclarednames">LexicallyDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21970"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> contains any duplicate entries<span normative-optional="">, unless the <emu-xref href="#host" id="_ref_7390"><a href="overview.html#host">host</a></emu-xref> is a web browser or otherwise supports <emu-xref href="#sec-block-level-function-declarations-web-legacy-compatibility-semantics" title="" id="_ref_458"><a href="additional-ecmascript-features-for-web-browsers.html#sec-block-level-function-declarations-web-legacy-compatibility-semantics">Block-Level Function Declarations Web Legacy Compatibility Semantics</a></emu-xref>, and both of the following conditions are true:</span></p>
<ul normative-optional="">
<li><emu-xref aoid="IsStrict" id="_ref_7391"><a href="ecmascript-language-source-code.html#sec-isstrict">IsStrict</a></emu-xref>(this production) is <emu-val>false</emu-val>.</li>
<li>The duplicate entries are only bound by FunctionDeclarations.</li>
</ul>
</li>
<li>
It is a Syntax Error if any element of the <emu-xref aoid="LexicallyDeclaredNames" id="_ref_7392"><a href="syntax-directed-operations.html#sec-static-semantics-lexicallydeclarednames">LexicallyDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21971"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> also occurs in the <emu-xref aoid="VarDeclaredNames" id="_ref_7393"><a href="syntax-directed-operations.html#sec-static-semantics-vardeclarednames">VarDeclaredNames</a></emu-xref> of <emu-nt id="_ref_21972"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-runtime-semantics-caseblockevaluation" type="sdo" aoid="CaseBlockEvaluation">
<h1><span class="secnum">14.12.2</span> Runtime Semantics: CaseBlockEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7394"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> CaseBlockEvaluation takes argument <var>input</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7395"><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_7396"><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_7397"><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_7398"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="CaseBlock" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gbpaspne" id="prod--oXyocga">
<emu-t>{</emu-t>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-val>undefined</emu-val>.</li></ol></emu-alg>
<emu-grammar><emu-production name="CaseBlock" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="eerblgqb" id="prod-n6COrqbY">
<emu-t>{</emu-t>
<emu-nt id="_ref_21973"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>V</var> be <emu-val>undefined</emu-val>.</li><li>Let <var>A</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7399"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-nt id="_ref_21974"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> items in <emu-nt id="_ref_21975"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt>, in source text order.</li><li>Let <var>found</var> be <emu-val>false</emu-val>.</li><li>For each <emu-nt id="_ref_21976"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <var>C</var> of <var>A</var>, do<ol><li>If <var>found</var> is <emu-val>false</emu-val>, then<ol><li>Set <var>found</var> to ?&nbsp;<emu-xref aoid="CaseClauseIsSelected" id="_ref_7400"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-caseclauseisselected" class="e-user-code">CaseClauseIsSelected</a></emu-xref>(<var>C</var>, <var>input</var>).</li></ol></li><li>If <var>found</var> is <emu-val>true</emu-val>, then<ol><li>Let <var>R</var> be <emu-xref aoid="Completion" id="_ref_7401"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7402"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>C</var>).</li><li>If <var>R</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>R</var>.<var class="field">[[Value]]</var>.</li><li>If <var>R</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7403"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7404"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>R</var>, <var>V</var>).</li></ol></li></ol></li><li>Return <var>V</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="CaseBlock" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ududlhou" id="prod-bc5B_Aaw">
<emu-t>{</emu-t>
<emu-nt optional="" id="_ref_21977"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-nt id="_ref_21978"><a href="ecmascript-language-statements-and-declarations.html#prod-DefaultClause">DefaultClause</a></emu-nt>
<emu-nt optional="" id="_ref_21979"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
<emu-t>}</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>V</var> be <emu-val>undefined</emu-val>.</li><li>If the first <emu-nt id="_ref_21980"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt> is present, then<ol><li>Let <var>A</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7405"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-nt id="_ref_21981"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> items in the first <emu-nt id="_ref_21982"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt>, in source text order.</li></ol></li><li>Else,<ol><li>Let <var>A</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7406"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li></ol></li><li>Let <var>found</var> be <emu-val>false</emu-val>.</li><li>For each <emu-nt id="_ref_21983"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <var>C</var> of <var>A</var>, do<ol><li>If <var>found</var> is <emu-val>false</emu-val>, then<ol><li>Set <var>found</var> to ?&nbsp;<emu-xref aoid="CaseClauseIsSelected" id="_ref_7407"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-caseclauseisselected" class="e-user-code">CaseClauseIsSelected</a></emu-xref>(<var>C</var>, <var>input</var>).</li></ol></li><li>If <var>found</var> is <emu-val>true</emu-val>, then<ol><li>Let <var>R</var> be <emu-xref aoid="Completion" id="_ref_7408"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7409"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <var>C</var>).</li><li>If <var>R</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>R</var>.<var class="field">[[Value]]</var>.</li><li>If <var>R</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7410"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7411"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>R</var>, <var>V</var>).</li></ol></li></ol></li><li>Let <var>foundInB</var> be <emu-val>false</emu-val>.</li><li>If the second <emu-nt id="_ref_21984"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt> is present, then<ol><li>Let <var>B</var> be the <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7412"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of <emu-nt id="_ref_21985"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> items in the second <emu-nt id="_ref_21986"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt>, in source text order.</li></ol></li><li>Else,<ol><li>Let <var>B</var> be a new empty <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7413"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref>.</li></ol></li><li>If <var>found</var> is <emu-val>false</emu-val>, then<ol><li>For each <emu-nt id="_ref_21987"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <var>C</var> of <var>B</var>, do<ol><li>If <var>foundInB</var> is <emu-val>false</emu-val>, then<ol><li>Set <var>foundInB</var> to ?&nbsp;<emu-xref aoid="CaseClauseIsSelected" id="_ref_7414"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-caseclauseisselected" class="e-user-code">CaseClauseIsSelected</a></emu-xref>(<var>C</var>, <var>input</var>).</li></ol></li><li>If <var>foundInB</var> is <emu-val>true</emu-val>, then<ol><li>Let <var>R</var> be <emu-xref aoid="Completion" id="_ref_7415"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7416"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21988"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <var>C</var>).</li><li>If <var>R</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>R</var>.<var class="field">[[Value]]</var>.</li><li>If <var>R</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7417"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7418"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>R</var>, <var>V</var>).</li></ol></li></ol></li></ol></li><li>If <var>foundInB</var> is <emu-val>true</emu-val>, return <var>V</var>.</li><li>Let <var>defaultR</var> be <emu-xref aoid="Completion" id="_ref_7419"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7420"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21989"><a href="ecmascript-language-statements-and-declarations.html#prod-DefaultClause">DefaultClause</a></emu-nt>).</li><li>If <var>defaultR</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>defaultR</var>.<var class="field">[[Value]]</var>.</li><li>If <var>defaultR</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7421"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7422"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>defaultR</var>, <var>V</var>).</li><li>NOTE: The following is another complete iteration of the second <emu-nt id="_ref_21990"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClauses">CaseClauses</a></emu-nt>.</li><li>For each <emu-nt id="_ref_21991"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <var>C</var> of <var>B</var>, do<ol><li>Let <var>R</var> be <emu-xref aoid="Completion" id="_ref_7423"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7424"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_21992"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <var>C</var>).</li><li>If <var>R</var>.<var class="field">[[Value]]</var> is not <emu-const>empty</emu-const>, set <var>V</var> to <var>R</var>.<var class="field">[[Value]]</var>.</li><li>If <var>R</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7425"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7426"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>R</var>, <var>V</var>).</li></ol></li><li>Return <var>V</var>.</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-runtime-semantics-caseclauseisselected" type="abstract operation" oldids="sec-runtime-semantics-caseselectorevaluation" aoid="CaseClauseIsSelected"><span id="sec-runtime-semantics-caseselectorevaluation"></span>
<h1><span class="secnum">14.12.3</span> CaseClauseIsSelected ( <var>C</var>, <var>input</var> )</h1>
<p>The abstract operation CaseClauseIsSelected takes arguments <var>C</var> (a <emu-nt id="_ref_21993"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7427"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>) and <var>input</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7428"><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_7429"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion containing</a></emu-xref> a Boolean or an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7430"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It determines whether <var>C</var> matches <var>input</var>. It performs the following steps when called:</p>
<emu-alg><ol><li><emu-xref href="#assert" id="_ref_7431"><a href="notational-conventions.html#assert">Assert</a></emu-xref>: <var>C</var> is an instance of the production <emu-grammar><emu-production name="CaseClause" collapsed="" class=" inline">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="x20nmjyd">
<emu-t>case</emu-t>
<emu-nt id="_ref_21994"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>:</emu-t>
<emu-nt optional="" id="_ref_21995"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a><emu-mods><emu-opt>opt</emu-opt></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>.</li><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7432"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of the <emu-nt id="_ref_21996"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt> of <var>C</var>.</li><li>Let <var>clauseSelector</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7433"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li><li>Return <emu-xref aoid="IsStrictlyEqual" id="_ref_7434"><a href="abstract-operations.html#sec-isstrictlyequal">IsStrictlyEqual</a></emu-xref>(<var>input</var>, <var>clauseSelector</var>).</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>This operation does not execute <var>C</var>'s <emu-nt id="_ref_21997"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt> (if any). The <emu-nt id="_ref_21998"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> algorithm uses its return value to determine which <emu-nt id="_ref_21999"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt> to start executing.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-switch-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.12.4</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="SwitchStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uvrp_hkw" id="prod-raA0Z_ll">
<emu-t>switch</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_22000"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_22001"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7435"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22002"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>switchValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7436"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li><li>Let <var>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7437"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>blockEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_7438"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>oldEnv</var>).</li><li>Perform <emu-xref aoid="BlockDeclarationInstantiation" id="_ref_7439"><a href="ecmascript-language-statements-and-declarations.html#sec-blockdeclarationinstantiation">BlockDeclarationInstantiation</a></emu-xref>(<emu-nt id="_ref_22003"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt>, <var>blockEnv</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7440"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>blockEnv</var>.</li><li>Let <var>R</var> be <emu-xref aoid="Completion" id="_ref_7441"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="CaseBlockEvaluation" id="_ref_7442"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-caseblockevaluation" class="e-user-code">CaseBlockEvaluation</a></emu-xref> of <emu-nt id="_ref_22004"><a href="ecmascript-language-statements-and-declarations.html#prod-CaseBlock">CaseBlock</a></emu-nt> with argument <var>switchValue</var>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7443"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return <var>R</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>No matter how control leaves the <emu-nt id="_ref_22005"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt> the LexicalEnvironment is always restored to its former state.</p>
</div></emu-note>
<emu-grammar><emu-production name="CaseClause" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="amgxmkjg" id="prod-pfa8PeiE">
<emu-t>case</emu-t>
<emu-nt id="_ref_22006"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>:</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="CaseClause" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CaseClause">CaseClause</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="eencdyk7" id="prod-SiRXsnRx">
<emu-t>case</emu-t>
<emu-nt id="_ref_22007"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>:</emu-t>
<emu-nt id="_ref_22008"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7444"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22009"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>.</li></ol></emu-alg>
<emu-grammar><emu-production name="DefaultClause" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-DefaultClause">DefaultClause</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="t5rjsefq" id="prod-f0Rq5Irs">
<emu-t>default</emu-t>
<emu-t>:</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
<emu-grammar><emu-production name="DefaultClause" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-DefaultClause">DefaultClause</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="odaivkwk" id="prod-eOryVE-Y">
<emu-t>default</emu-t>
<emu-t>:</emu-t>
<emu-nt id="_ref_22010"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7445"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22011"><a href="ecmascript-language-statements-and-declarations.html#prod-StatementList">StatementList</a></emu-nt>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-labelled-statements">
<h1><span class="secnum">14.13</span> Labelled Statements</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="LabelledStatement" params="Yield, Await, Return" id="prod-LabelledStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="vhxkapdt" id="prod-0GG8m5VC">
<emu-nt params="?Yield, ?Await" id="_ref_22012"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>:</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22013"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="LabelledItem" params="Yield, Await, Return" id="prod-LabelledItem">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="septp5sa" id="prod-YaWmIZ1c">
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22014"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="d0nwjyav" id="prod-GPTeOVBJ">
<emu-nt params="?Yield, ?Await, ~Default" id="_ref_22015"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a><emu-mods><emu-params>[?Yield, ?Await, ~Default]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>A <emu-nt id="_ref_22016"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> may be prefixed by a label. Labelled statements are only used in conjunction with labelled <code>break</code> and <code>continue</code> statements. ECMAScript has no <code>goto</code> statement. A <emu-nt id="_ref_22017"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> can be part of a <emu-nt id="_ref_22018"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt>, which itself can be part of a <emu-nt id="_ref_22019"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt>, and so on. The labels introduced this way are collectively referred to as the “current label set” when describing the semantics of individual statements.</p>
</div></emu-note>
<emu-clause id="sec-labelled-statements-static-semantics-early-errors">
<h1><span class="secnum">14.13.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="LabelledItem" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="-nqupnlb"><emu-nt id="_ref_22020"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if any source text is matched by this production<span normative-optional="">, unless that source text is <emu-xref href="#non-strict-code" id="_ref_7446"><a href="ecmascript-language-source-code.html#non-strict-code">non-strict code</a></emu-xref> and the <emu-xref href="#host" id="_ref_7447"><a href="overview.html#host">host</a></emu-xref> is a web browser or otherwise supports <emu-xref href="#sec-labelled-function-declarations" title="" id="_ref_459"><a href="additional-ecmascript-features-for-web-browsers.html#sec-labelled-function-declarations">Labelled Function Declarations</a></emu-xref></span>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-islabelledfunction" type="abstract operation" aoid="IsLabelledFunction">
<h1><span class="secnum">14.13.2</span> Static Semantics: IsLabelledFunction ( <var>stmt</var> )</h1>
<p>The abstract operation IsLabelledFunction takes argument <var>stmt</var> (a <emu-nt id="_ref_22021"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> <emu-xref href="#sec-syntactic-grammar" id="_ref_7448"><a href="notational-conventions.html#sec-syntactic-grammar">Parse Node</a></emu-xref>) and returns a Boolean. It performs the following steps when called:</p>
<emu-alg><ol><li>If <var>stmt</var> is not a <emu-nt id="_ref_22022"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt>, return <emu-val>false</emu-val>.</li><li>Let <var>item</var> be the <emu-nt id="_ref_22023"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt> of <var>stmt</var>.</li><li>If <var>item</var> is <emu-grammar><emu-production name="LabelledItem" collapsed="" class=" inline">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="-nqupnlb"><emu-nt id="_ref_22024"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>, return <emu-val>true</emu-val>.</li><li>Let <var>subStmt</var> be the <emu-nt id="_ref_22025"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> of <var>item</var>.</li><li>Return <emu-xref aoid="IsLabelledFunction" id="_ref_7449"><a href="ecmascript-language-statements-and-declarations.html#sec-islabelledfunction">IsLabelledFunction</a></emu-xref>(<var>subStmt</var>).</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-labelled-statements-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.13.3</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="LabelledStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ubbvtbun" id="prod-z6MMrwO3">
<emu-nt id="_ref_22026"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>
<emu-t>:</emu-t>
<emu-nt id="_ref_22027"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="LabelledEvaluation" id="_ref_7450"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-labelledevaluation" class="e-user-code">LabelledEvaluation</a></emu-xref> of this <emu-nt id="_ref_22028"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt> with argument «&nbsp;».</li></ol></emu-alg>
</emu-clause>
<emu-clause id="sec-runtime-semantics-labelledevaluation" oldids="sec-statement-semantics-runtime-semantics-labelledevaluation,sec-labelled-statements-runtime-semantics-labelledevaluation" type="sdo" aoid="LabelledEvaluation"><span id="sec-labelled-statements-runtime-semantics-labelledevaluation"></span><span id="sec-statement-semantics-runtime-semantics-labelledevaluation"></span>
<h1><span class="secnum">14.13.4</span> Runtime Semantics: LabelledEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7451"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> LabelledEvaluation takes argument <var>labelSet</var> (a <emu-xref href="#sec-list-and-record-specification-type" id="_ref_7452"><a href="ecmascript-data-types-and-values.html#sec-list-and-record-specification-type">List</a></emu-xref> of Strings) and returns either a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7453"><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_7454"><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 an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7455"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="BreakableStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="kmxl4yum" id="prod-pR7DNQsN"><emu-nt id="_ref_22029"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>stmtResult</var> be <emu-xref aoid="Completion" id="_ref_7456"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="LoopEvaluation" id="_ref_7457"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-loopevaluation" class="e-user-code">LoopEvaluation</a></emu-xref> of <emu-nt id="_ref_22030"><a href="ecmascript-language-statements-and-declarations.html#prod-IterationStatement">IterationStatement</a></emu-nt> with argument <var>labelSet</var>).</li><li>If <var>stmtResult</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7458"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">break completion</a></emu-xref>, then<ol><li>If <var>stmtResult</var>.<var class="field">[[Target]]</var> is <emu-const>empty</emu-const>, then<ol><li>If <var>stmtResult</var>.<var class="field">[[Value]]</var> is <emu-const>empty</emu-const>, set <var>stmtResult</var> to <emu-xref aoid="NormalCompletion" id="_ref_7459"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Else, set <var>stmtResult</var> to <emu-xref aoid="NormalCompletion" id="_ref_7460"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>stmtResult</var>.<var class="field">[[Value]]</var>).</li></ol></li></ol></li><li>Return ?&nbsp;<var>stmtResult</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="BreakableStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="nuio-xfp" id="prod-FSHcHfYw"><emu-nt id="_ref_22031"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>stmtResult</var> be <emu-xref aoid="Completion" id="_ref_7461"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7462"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22032"><a href="ecmascript-language-statements-and-declarations.html#prod-SwitchStatement">SwitchStatement</a></emu-nt>).</li><li>If <var>stmtResult</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7463"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">break completion</a></emu-xref>, then<ol><li>If <var>stmtResult</var>.<var class="field">[[Target]]</var> is <emu-const>empty</emu-const>, then<ol><li>If <var>stmtResult</var>.<var class="field">[[Value]]</var> is <emu-const>empty</emu-const>, set <var>stmtResult</var> to <emu-xref aoid="NormalCompletion" id="_ref_7464"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<emu-val>undefined</emu-val>).</li><li>Else, set <var>stmtResult</var> to <emu-xref aoid="NormalCompletion" id="_ref_7465"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>stmtResult</var>.<var class="field">[[Value]]</var>).</li></ol></li></ol></li><li>Return ?&nbsp;<var>stmtResult</var>.</li></ol></emu-alg>
<emu-note><span class="note">Note 1</span><div class="note-contents">
<p>A <emu-nt id="_ref_22033"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a></emu-nt> is one that can be exited via an unlabelled <emu-nt id="_ref_22034"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a></emu-nt>.</p>
</div></emu-note>
<emu-grammar><emu-production name="LabelledStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ubbvtbun" id="prod-GnWrgP5w">
<emu-nt id="_ref_22035"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>
<emu-t>:</emu-t>
<emu-nt id="_ref_22036"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>label</var> be the <emu-xref aoid="StringValue" id="_ref_7466"><a href="ecmascript-language-expressions.html#sec-static-semantics-stringvalue">StringValue</a></emu-xref> of <emu-nt id="_ref_22037"><a href="ecmascript-language-expressions.html#prod-LabelIdentifier">LabelIdentifier</a></emu-nt>.</li><li>Let <var>newLabelSet</var> be the <emu-xref href="#list-concatenation" id="_ref_7467"><a href="ecmascript-data-types-and-values.html#list-concatenation">list-concatenation</a></emu-xref> of <var>labelSet</var> and « <var>label</var>&nbsp;».</li><li>Let <var>stmtResult</var> be <emu-xref aoid="Completion" id="_ref_7468"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="LabelledEvaluation" id="_ref_7469"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-labelledevaluation" class="e-user-code">LabelledEvaluation</a></emu-xref> of <emu-nt id="_ref_22038"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt> with argument <var>newLabelSet</var>).</li><li>If <var>stmtResult</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7470"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">break completion</a></emu-xref> and <var>stmtResult</var>.<var class="field">[[Target]]</var> is <var>label</var>, then<ol><li>Set <var>stmtResult</var> to <emu-xref aoid="NormalCompletion" id="_ref_7471"><a href="ecmascript-data-types-and-values.html#sec-normalcompletion">NormalCompletion</a></emu-xref>(<var>stmtResult</var>.<var class="field">[[Value]]</var>).</li></ol></li><li>Return ?&nbsp;<var>stmtResult</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="LabelledItem" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledItem">LabelledItem</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="-nqupnlb" id="prod-3whCJM4e"><emu-nt id="_ref_22039"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7472"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22040"><a href="ecmascript-language-functions-and-classes.html#prod-FunctionDeclaration">FunctionDeclaration</a></emu-nt>.</li></ol></emu-alg>
<emu-grammar><emu-production name="Statement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gre9qn6e" id="prod-yFnpxPRG">
<emu-nt id="_ref_22041"><a href="ecmascript-language-statements-and-declarations.html#prod-BlockStatement">BlockStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="iwwn8atx" id="prod-Ebz5cXwH">
<emu-nt id="_ref_22042"><a href="ecmascript-language-statements-and-declarations.html#prod-VariableStatement">VariableStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="cziqu-45" id="prod-qI_HU3XB">
<emu-nt id="_ref_22043"><a href="ecmascript-language-statements-and-declarations.html#prod-EmptyStatement">EmptyStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="gsqkt2bv" id="prod-aRwgRfmk">
<emu-nt id="_ref_22044"><a href="ecmascript-language-statements-and-declarations.html#prod-ExpressionStatement">ExpressionStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="skawbrez" id="prod-RLprpFgP">
<emu-nt id="_ref_22045"><a href="ecmascript-language-statements-and-declarations.html#prod-IfStatement">IfStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="hx0ynljx" id="prod-4r9ecQgz">
<emu-nt id="_ref_22046"><a href="ecmascript-language-statements-and-declarations.html#prod-ContinueStatement">ContinueStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="q4uv-sm3" id="prod-VyFRxEGQ">
<emu-nt id="_ref_22047"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakStatement">BreakStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="qm95e4wi" id="prod-Hgg1wqRZ">
<emu-nt id="_ref_22048"><a href="ecmascript-language-statements-and-declarations.html#prod-ReturnStatement">ReturnStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="ye6wwgts" id="prod-wFzN_sG0">
<emu-nt id="_ref_22049"><a href="ecmascript-language-statements-and-declarations.html#prod-WithStatement">WithStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="hntake-o" id="prod-q_qjzdry">
<emu-nt id="_ref_22050"><a href="ecmascript-language-statements-and-declarations.html#prod-ThrowStatement">ThrowStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="ex_crokj" id="prod-7PJ339VQ">
<emu-nt id="_ref_22051"><a href="ecmascript-language-statements-and-declarations.html#prod-TryStatement">TryStatement</a></emu-nt>
</emu-rhs>
<emu-rhs a="iseu28qi" id="prod-O3yX8Gg7">
<emu-nt id="_ref_22052"><a href="ecmascript-language-statements-and-declarations.html#prod-DebuggerStatement">DebuggerStatement</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7473"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22053"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt>.</li></ol></emu-alg>
<emu-note><span class="note">Note 2</span><div class="note-contents">
<p>The only two productions of <emu-nt id="_ref_22054"><a href="ecmascript-language-statements-and-declarations.html#prod-Statement">Statement</a></emu-nt> which have special semantics for LabelledEvaluation are <emu-nt id="_ref_22055"><a href="ecmascript-language-statements-and-declarations.html#prod-BreakableStatement">BreakableStatement</a></emu-nt> and <emu-nt id="_ref_22056"><a href="ecmascript-language-statements-and-declarations.html#prod-LabelledStatement">LabelledStatement</a></emu-nt>.</p>
</div></emu-note>
</emu-clause>
</emu-clause>
<emu-clause id="sec-throw-statement">
<h1><span class="secnum">14.14</span> The <code>throw</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="ThrowStatement" params="Yield, Await" id="prod-ThrowStatement">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-ThrowStatement">ThrowStatement</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="q_cybpdb" id="prod-E5ckYtCh">
<emu-t>throw</emu-t>
<emu-gann>[no <emu-nt id="_ref_22057"><a href="ecmascript-language-lexical-grammar.html#prod-LineTerminator">LineTerminator</a></emu-nt> here]</emu-gann>
<emu-nt params="+In, ?Yield, ?Await" id="_ref_22058"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a><emu-mods><emu-params>[+In, ?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-throw-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.14.1</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="ThrowStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-ThrowStatement">ThrowStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="lauy4mhi" id="prod-fEMuit66">
<emu-t>throw</emu-t>
<emu-nt id="_ref_22059"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>exprRef</var> be ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7474"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22060"><a href="ecmascript-language-expressions.html#prod-Expression">Expression</a></emu-nt>.</li><li>Let <var>exprValue</var> be ?&nbsp;<emu-xref aoid="GetValue" id="_ref_7475"><a href="ecmascript-data-types-and-values.html#sec-getvalue" class="e-user-code">GetValue</a></emu-xref>(<var>exprRef</var>).</li><li>Return <emu-xref aoid="ThrowCompletion" id="_ref_7476"><a href="ecmascript-data-types-and-values.html#sec-throwcompletion">ThrowCompletion</a></emu-xref>(<var>exprValue</var>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-try-statement">
<h1><span class="secnum">14.15</span> The <code>try</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="TryStatement" params="Yield, Await, Return" id="prod-TryStatement">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-TryStatement">TryStatement</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="eqx7gx8m" id="prod-wD-TPYub">
<emu-t>try</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22061"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22062"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="ayio9dod" id="prod-EYIEedje">
<emu-t>try</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22063"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22064"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="yfzmez3t" id="prod-cfkI0NCS">
<emu-t>try</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22065"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22066"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22067"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="Catch" params="Yield, Await, Return" id="prod-Catch">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gk6mks18" id="prod-IbvHsEaf">
<emu-t>catch</emu-t>
<emu-t>(</emu-t>
<emu-nt params="?Yield, ?Await" id="_ref_22068"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
<emu-t>)</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22069"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="vi_srlx8" id="prod-ybInUotF">
<emu-t>catch</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22070"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="Finally" params="Yield, Await, Return" id="prod-Finally">
<emu-nt params="Yield, Await, Return"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a><emu-mods><emu-params>[Yield, Await, Return]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="e9akqlxo">
<emu-t>finally</emu-t>
<emu-nt params="?Yield, ?Await, ?Return" id="_ref_22071"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a><emu-mods><emu-params>[?Yield, ?Await, ?Return]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
<emu-production name="CatchParameter" params="Yield, Await" id="prod-CatchParameter">
<emu-nt params="Yield, Await"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a><emu-mods><emu-params>[Yield, Await]</emu-params></emu-mods></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ir-rfjfi">
<emu-nt params="?Yield, ?Await" id="_ref_22072"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
<emu-rhs a="nridwfya">
<emu-nt params="?Yield, ?Await" id="_ref_22073"><a href="ecmascript-language-statements-and-declarations.html#prod-BindingPattern">BindingPattern</a><emu-mods><emu-params>[?Yield, ?Await]</emu-params></emu-mods></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>The <code>try</code> statement encloses a block of code in which an exceptional condition can occur, such as a runtime error or a <code>throw</code> statement. The <code>catch</code> clause provides the exception-handling code. When a catch clause catches an exception, its <emu-nt id="_ref_22074"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> is bound to that exception.</p>
</div></emu-note>
<emu-clause id="sec-try-statement-static-semantics-early-errors">
<h1><span class="secnum">14.15.1</span> Static Semantics: Early Errors</h1>
<emu-grammar><emu-production name="Catch" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="3ce8nhiw">
<emu-t>catch</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_22075"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_22076"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<ul>
<li>
It is a Syntax Error if the <emu-xref aoid="BoundNames" id="_ref_7477"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_22077"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> contains any duplicate elements.
</li>
<li>
It is a Syntax Error if any element of the <emu-xref aoid="BoundNames" id="_ref_7478"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_22078"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> also occurs in the <emu-xref aoid="LexicallyDeclaredNames" id="_ref_7479"><a href="syntax-directed-operations.html#sec-static-semantics-lexicallydeclarednames">LexicallyDeclaredNames</a></emu-xref> of <emu-nt id="_ref_22079"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>.
</li>
<li>
It is a Syntax Error if any element of the <emu-xref aoid="BoundNames" id="_ref_7480"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_22080"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> also occurs in the <emu-xref aoid="VarDeclaredNames" id="_ref_7481"><a href="syntax-directed-operations.html#sec-static-semantics-vardeclarednames">VarDeclaredNames</a></emu-xref> of <emu-nt id="_ref_22081"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt><span normative-optional="">, unless <emu-nt id="_ref_22082"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> is <emu-grammar><emu-production name="CatchParameter" collapsed="" class=" inline">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="uolyom43"><emu-nt id="_ref_22083"><a href="ecmascript-language-expressions.html#prod-BindingIdentifier">BindingIdentifier</a></emu-nt></emu-rhs>
</emu-production>
</emu-grammar> and the <emu-xref href="#host" id="_ref_7482"><a href="overview.html#host">host</a></emu-xref> is a web browser or otherwise supports <emu-xref href="#sec-variablestatements-in-catch-blocks" title="" id="_ref_460"><a href="additional-ecmascript-features-for-web-browsers.html#sec-variablestatements-in-catch-blocks">VariableStatements in Catch Blocks</a></emu-xref></span>.
</li>
</ul>
</emu-clause>
<emu-clause id="sec-runtime-semantics-catchclauseevaluation" type="sdo" aoid="CatchClauseEvaluation">
<h1><span class="secnum">14.15.2</span> Runtime Semantics: CatchClauseEvaluation</h1>
<p>The <emu-xref href="#sec-algorithm-conventions-syntax-directed-operations" id="_ref_7483"><a href="notational-conventions.html#sec-algorithm-conventions-syntax-directed-operations">syntax-directed operation</a></emu-xref> CatchClauseEvaluation takes argument <var>thrownValue</var> (an <emu-xref href="#sec-ecmascript-language-types" id="_ref_7484"><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_7485"><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_7486"><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 an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7487"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>. It is defined piecewise over the following productions:</p>
<emu-grammar><emu-production name="Catch" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="3ce8nhiw" id="prod-tivA4mFO">
<emu-t>catch</emu-t>
<emu-t>(</emu-t>
<emu-nt id="_ref_22084"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt>
<emu-t>)</emu-t>
<emu-nt id="_ref_22085"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>oldEnv</var> be the <emu-xref href="#running-execution-context" id="_ref_7488"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment.</li><li>Let <var>catchEnv</var> be <emu-xref aoid="NewDeclarativeEnvironment" id="_ref_7489"><a href="executable-code-and-execution-contexts.html#sec-newdeclarativeenvironment">NewDeclarativeEnvironment</a></emu-xref>(<var>oldEnv</var>).</li><li>For each element <var>argName</var> of the <emu-xref aoid="BoundNames" id="_ref_7490"><a href="syntax-directed-operations.html#sec-static-semantics-boundnames">BoundNames</a></emu-xref> of <emu-nt id="_ref_22086"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt>, do<ol><li>Perform !&nbsp;<var>catchEnv</var>.<emu-xref aoid="CreateMutableBinding" id="_ref_7491"><a href="executable-code-and-execution-contexts.html#abstract-createmutablebinding">CreateMutableBinding</a></emu-xref>(<var>argName</var>, <emu-val>false</emu-val>).</li></ol></li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7492"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>catchEnv</var>.</li><li>Let <var>status</var> be <emu-xref aoid="Completion" id="_ref_7493"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="BindingInitialization" id="_ref_7494"><a href="syntax-directed-operations.html#sec-runtime-semantics-bindinginitialization" class="e-user-code">BindingInitialization</a></emu-xref> of <emu-nt id="_ref_22087"><a href="ecmascript-language-statements-and-declarations.html#prod-CatchParameter">CatchParameter</a></emu-nt> with arguments <var>thrownValue</var> and <var>catchEnv</var>).</li><li>If <var>status</var> is an <emu-xref href="#sec-completion-record-specification-type" id="_ref_7495"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">abrupt completion</a></emu-xref>, then<ol><li>Set the <emu-xref href="#running-execution-context" id="_ref_7496"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return ?&nbsp;<var>status</var>.</li></ol></li><li>Let <var>B</var> be <emu-xref aoid="Completion" id="_ref_7497"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7498"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22088"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>).</li><li>Set the <emu-xref href="#running-execution-context" id="_ref_7499"><a href="executable-code-and-execution-contexts.html#running-execution-context">running execution context</a></emu-xref>'s LexicalEnvironment to <var>oldEnv</var>.</li><li>Return ?&nbsp;<var>B</var>.</li></ol></emu-alg>
<emu-grammar><emu-production name="Catch" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="oyp2rsut" id="prod-7Gz_IT_v">
<emu-t>catch</emu-t>
<emu-nt id="_ref_22089"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Return ?&nbsp;<emu-xref aoid="Evaluation" id="_ref_7500"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22090"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>.</li></ol></emu-alg>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>No matter how control leaves the <emu-nt id="_ref_22091"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt> the LexicalEnvironment is always restored to its former state.</p>
</div></emu-note>
</emu-clause>
<emu-clause id="sec-try-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.15.3</span> Runtime Semantics: Evaluation</h1>
<emu-grammar><emu-production name="TryStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-TryStatement">TryStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="qhfov2lc" id="prod-TjGqXGk4">
<emu-t>try</emu-t>
<emu-nt id="_ref_22092"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>
<emu-nt id="_ref_22093"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>B</var> be <emu-xref aoid="Completion" id="_ref_7501"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7502"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22094"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>).</li><li>If <var>B</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7503"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>, let <var>C</var> be <emu-xref aoid="Completion" id="_ref_7504"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="CatchClauseEvaluation" id="_ref_7505"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-catchclauseevaluation" class="e-user-code">CatchClauseEvaluation</a></emu-xref> of <emu-nt id="_ref_22095"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt> with argument <var>B</var>.<var class="field">[[Value]]</var>).</li><li>Else, let <var>C</var> be <var>B</var>.</li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7506"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>C</var>, <emu-val>undefined</emu-val>).</li></ol></emu-alg>
<emu-grammar><emu-production name="TryStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-TryStatement">TryStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="xsakufa6" id="prod-BNnGZMkj">
<emu-t>try</emu-t>
<emu-nt id="_ref_22096"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>
<emu-nt id="_ref_22097"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>B</var> be <emu-xref aoid="Completion" id="_ref_7507"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7508"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22098"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>).</li><li>Let <var>F</var> be <emu-xref aoid="Completion" id="_ref_7509"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7510"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22099"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a></emu-nt>).</li><li>If <var>F</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7511"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, set <var>F</var> to <var>B</var>.</li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7512"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>F</var>, <emu-val>undefined</emu-val>).</li></ol></emu-alg>
<emu-grammar><emu-production name="TryStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-TryStatement">TryStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="gxlzfd5s" id="prod-fUrDxi55">
<emu-t>try</emu-t>
<emu-nt id="_ref_22100"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>
<emu-nt id="_ref_22101"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt>
<emu-nt id="_ref_22102"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a></emu-nt>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>Let <var>B</var> be <emu-xref aoid="Completion" id="_ref_7513"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7514"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22103"><a href="ecmascript-language-statements-and-declarations.html#prod-Block">Block</a></emu-nt>).</li><li>If <var>B</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7515"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">throw completion</a></emu-xref>, let <var>C</var> be <emu-xref aoid="Completion" id="_ref_7516"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="CatchClauseEvaluation" id="_ref_7517"><a href="ecmascript-language-statements-and-declarations.html#sec-runtime-semantics-catchclauseevaluation" class="e-user-code">CatchClauseEvaluation</a></emu-xref> of <emu-nt id="_ref_22104"><a href="ecmascript-language-statements-and-declarations.html#prod-Catch">Catch</a></emu-nt> with argument <var>B</var>.<var class="field">[[Value]]</var>).</li><li>Else, let <var>C</var> be <var>B</var>.</li><li>Let <var>F</var> be <emu-xref aoid="Completion" id="_ref_7518"><a href="notational-conventions.html#sec-completion-ao">Completion</a></emu-xref>(<emu-xref aoid="Evaluation" id="_ref_7519"><a href="syntax-directed-operations.html#sec-evaluation" class="e-user-code">Evaluation</a></emu-xref> of <emu-nt id="_ref_22105"><a href="ecmascript-language-statements-and-declarations.html#prod-Finally">Finally</a></emu-nt>).</li><li>If <var>F</var> is a <emu-xref href="#sec-completion-record-specification-type" id="_ref_7520"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">normal completion</a></emu-xref>, set <var>F</var> to <var>C</var>.</li><li>Return ?&nbsp;<emu-xref aoid="UpdateEmpty" id="_ref_7521"><a href="ecmascript-data-types-and-values.html#sec-updateempty">UpdateEmpty</a></emu-xref>(<var>F</var>, <emu-val>undefined</emu-val>).</li></ol></emu-alg>
</emu-clause>
</emu-clause>
<emu-clause id="sec-debugger-statement">
<h1><span class="secnum">14.16</span> The <code>debugger</code> Statement</h1>
<h2>Syntax</h2>
<emu-grammar type="definition"><emu-production name="DebuggerStatement" id="prod-DebuggerStatement">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-DebuggerStatement">DebuggerStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ns5hclvt" id="prod-Kx8jxmHA">
<emu-t>debugger</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-clause id="sec-debugger-statement-runtime-semantics-evaluation" type="sdo">
<h1><span class="secnum">14.16.1</span> Runtime Semantics: Evaluation</h1>
<emu-note><span class="note">Note</span><div class="note-contents">
<p>Evaluating a <emu-nt id="_ref_22106"><a href="ecmascript-language-statements-and-declarations.html#prod-DebuggerStatement">DebuggerStatement</a></emu-nt> may allow an implementation to cause a breakpoint when run under a debugger. If a debugger is not present or active this statement has no observable effect.</p>
</div></emu-note>
<emu-grammar><emu-production name="DebuggerStatement" collapsed="">
<emu-nt><a href="ecmascript-language-statements-and-declarations.html#prod-DebuggerStatement">DebuggerStatement</a></emu-nt> <emu-geq>:</emu-geq> <emu-rhs a="ns5hclvt" id="prod-eDCsgVlr">
<emu-t>debugger</emu-t>
<emu-t>;</emu-t>
</emu-rhs>
</emu-production>
</emu-grammar>
<emu-alg><ol><li>If an <emu-xref href="#implementation-defined" id="_ref_7522"><a href="overview.html#implementation-defined">implementation-defined</a></emu-xref> debugging facility is available and enabled, then<ol><li>Perform an <emu-xref href="#implementation-defined" id="_ref_7523"><a href="overview.html#implementation-defined">implementation-defined</a></emu-xref> debugging action.</li><li>Return a new <emu-xref href="#implementation-defined" id="_ref_7524"><a href="overview.html#implementation-defined">implementation-defined</a></emu-xref> <emu-xref href="#sec-completion-record-specification-type" id="_ref_7525"><a href="ecmascript-data-types-and-values.html#sec-completion-record-specification-type">Completion Record</a></emu-xref>.</li></ol></li><li>Return <emu-const>empty</emu-const>.</li></ol></emu-alg>
</emu-clause>
</emu-clause>
</emu-clause></div></body>
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