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  • Revision slug: Web/JavaScript
  • Revision title: JavaScript
  • Revision id: 645921
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JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic,and supports object-oriented, imperative, and functional programming styles. Read more about JavaScript.

The JavaScript standard is ECMAScript. As of 2012, all modern browsers fully support ECMAScript 5.1. Older browsers support at least ECMAScript 3. A 6th major revision of the standard is in the works.

This section of the site is dedicated to the JavaScript language itself, the parts that are not specific to Web pages, or other host environments. For information about APIs specific to Web pages, please see Web APIs and DOM.

JavaScript is not to be confused with the Java programming language. JavaScript is a trademark or registered trademark of Oracle in the U.S. and other countries.

Tutorials

Learn how to program JavaScript.

Introductory

Getting started
Your first steps with JavaScript.
JavaScript Guide
If you are new to JavaScript, this guide will walk you through the language.
JavaScript technologies overview
Introduction to the web browser JavaScript landscape.
Introduction to Object Oriented JavaScript
Introduction to the concepts of object oriented programming in JavaScript.

Intermediate

A re-introduction to JavaScript
An overview for those who think they know about JavaScript.
JavaScript data structures
Overview of available data structures in JavaScript
Equality comparisons and when to use them
JavaScript provides three different value-comparison operations: strict equality using === and loose equality using ==.

Advanced

Inheritance and the prototype chain
Explanation of the widely misunderstood and under-estimated prototype-based inheritance.
Strict mode
A restricted variant of JavaScript.
JavaScript typed arrays
JavaScript typed arrays provide a mechanism for accessing raw binary data.
Memory Management
Memory life cycle and garbage collection in JavaScript.

Reference

Browse the complete language reference documentation.

Objects
Get to know standard built-in objects Object, Function, Boolean, Error, Number, Math, Date, String, RegExp, Array, Map, Set, WeakMap, WeakSet, JSON, and others.
Expressions & Operators
Learn more about the behavior of JavaScript's operators instanceof, typeof, new, this, and more.
Statements
Learn how do-while, for-in, for-of, try-catch, let, var, const, if-else, switch, and more JavaScript statements and keywords work.

Tools & resources

Helpful tools while writing and debugging your JavaScript code.

Firefox Developer Tools
Scratchpad, Web Console, JavaScript Profiler, Debugger, and more.
Firebug
Edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.
JavaScript Shells
A JavaScript shell allows you to quickly test snippets of JavaScript code.
Other JavaScript tools
This article provides a list of additional JavaScript development tools.
TogetherJS

Collaboration made easy.

Stack Overflow
Stack Overflow questions tagged with "JavaScript".

{{CommunityBox("JavaScript", "js-engine.internals", "mozilla.dev.tech.js-engine.internals", "js", "ES discuss|https://esdiscuss.org/|esdiscuss.org|ECMAScript standard discussion mailing list||SpiderMonkey|https://wiki.mozilla.org/JavaScript|Project page|Contribute to the JavaScript Engine||Twitter|https://twitter.com/FirefoxNightly|@FirefoxNightly|Firefox Nightly updates on Twitter")}}

Revision Source

 
<div class="summary">
 <p><strong>JavaScript</strong><sup>®</sup> (often shortened to <strong>JS</strong>) is a lightweight, interpreted, object-oriented language with <a href="https://en.wikipedia.org/wiki/First-class_functions" title="https://en.wikipedia.org/wiki/First-class_functions">first-class functions</a>, most known as the scripting language for Web pages, but <a class="external" href="https://en.wikipedia.org/wiki/JavaScript#Uses_outside_web_pages">used in many non-browser environments</a> as well such as <a class="external" href="https://nodejs.org/">node.js</a> or <a href="https://couchdb.apache.org">Apache CouchDB</a>. It is a <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Prototype-based" title="Prototype-based">prototype-based</a>, multi-paradigm scripting language that is dynamic,and supports object-oriented, imperative, and functional programming styles. Read more <a href="/en-US/docs/Web/JavaScript/About_JavaScript">about JavaScript</a>.</p>
</div>
<p>The JavaScript standard is <a href="/en-US/docs/JavaScript/Language_Resources">ECMAScript</a>. As of 2012, all modern browsers fully support ECMAScript 5.1. Older browsers support at least ECMAScript 3. A 6th major revision of the standard is in the works.</p>
<p>This section of the site is dedicated to the JavaScript language itself, the parts that are not specific to Web pages, or other host environments. For information about APIs specific to Web pages, please see <a href="/en-US/docs/Web/API">Web APIs</a> and <a href="/en-US/docs/Glossary/DOM">DOM</a>.</p>
<p>JavaScript is not to be confused with the&nbsp;<a href="https://en.wikipedia.org/wiki/Java_(programming_language)">Java programming language</a>. JavaScript is a trademark or registered trademark of Oracle in the U.S. and other countries.</p>
<div class="column-container">
 <div class="column-half">
  <h2 id="Creating" name="Creating">Tutorials</h2>
  <p>Learn how to program JavaScript.</p>
  <h3 id="Introductory">Introductory</h3>
  <dl>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Getting_Started">Getting started</a></dt>
   <dd>
    Your first steps with JavaScript.</dd>
  </dl>
  <dl>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide">JavaScript Guide</a></dt>
   <dd>
    If you are new to JavaScript, this guide will walk you through the language.</dd>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/JavaScript_technologies_overview">JavaScript technologies overview</a></dt>
   <dd>
    Introduction to the web browser JavaScript landscape.</dd>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Introduction_to_Object-Oriented_JavaScript">Introduction to Object Oriented JavaScript</a></dt>
   <dd>
    Introduction to the concepts of object oriented programming in JavaScript.</dd>
  </dl>
  <h3 id="Intermediate">Intermediate</h3>
  <dl>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript">A re-introduction to JavaScript</a></dt>
   <dd>
    An overview for those who <em>think</em> they know about JavaScript.</dd>
  </dl>
  <dl>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures">JavaScript data structures</a></dt>
   <dd>
    Overview of available data structures in JavaScript</dd>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_when_to_use_them">Equality comparisons and when to use them</a></dt>
   <dd>
    JavaScript provides three different value-comparison operations: strict equality using <code>===</code> and loose equality using <code>==.</code></dd>
  </dl>
  <h3 id="Advanced">Advanced</h3>
  <dl>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Inheritance_and_the_prototype_chain">Inheritance and the prototype chain</a></dt>
   <dd>
    Explanation of the widely misunderstood and under-estimated prototype-based inheritance.</dd>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/Strict_mode">Strict mode</a></dt>
   <dd>
    A restricted variant of JavaScript.</dd>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays">JavaScript typed arrays</a></dt>
   <dd>
    JavaScript typed arrays provide a mechanism for accessing raw binary data.</dd>
   <dt>
    <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_Management">Memory Management</a></dt>
   <dd>
    Memory life cycle and garbage collection in JavaScript.</dd>
  </dl>
 </div>
 <div class="column-half">
  <h2 id="Reference"><a href="/en-US/docs/Web/JavaScript/Reference">Reference</a></h2>
  <p>Browse the complete language reference documentation.</p>
  <dl>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects">Objects</a></dt>
   <dd>
    Get to know standard built-in objects <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" title="The Object constructor creates an object wrapper."><code>Object</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" title="The Function constructor creates a new Function object. In JavaScript every function is actually a Function object."><code>Function</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean" title="The Boolean object is an object wrapper for a boolean value."><code>Boolean</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" title="The Error constructor creates an error object. Instances of Error objects are thrown when runtime errors occur. The Error object can also be used as a base objects for user-defined exceptions. See below for standard built-in error types."><code>Error</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number" title="The Number JavaScript object is a wrapper object allowing you to work with numerical values. A Number object is created using the Number() constructor."><code>Number</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math" title="Math is a built-in object that has properties and methods for mathematical constants and functions. Not a function object."><code>Math</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date" title="Creates a JavaScript&nbsp;Date instance that represents a single moment in time. Date objects are based on a time value that is the number of milliseconds since 1 January, 1970 UTC."><code>Date</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String" title="The String global object is a constructor for strings, or a sequence of characters."><code>String</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp" title="The RegExp constructor creates a regular expression object for matching text with a pattern."><code>RegExp</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" title="The JavaScript Array global object is a constructor for arrays, which are high-level, list-like objects."><code>Array</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map" title="The Map object is a simple key/value map. Any value (both objects and primitive values) may be used as either a key or a value."><code>Map</code></a>, <code><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set">Set</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map" title="The Map object is a simple key/value map. Any value (both objects and primitive values) may be used as either a key or a value."><code>WeakMap</code></a></code>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet" title="The WeakSet object lets you store weakly held objects in a collection."><code>WeakSet</code></a>, <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON" title="The JSON object contains methods for parsing JavaScript Object Notation (JSON) and converting values to JSON. It can't be called or constructed, and aside from its two method properties it has no interesting functionality of its own."><code>JSON</code></a>, and others.</dd>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Reference/Operators">Expressions &amp; Operators</a></dt>
   <dd>
    Learn more about the behavior of JavaScript's operators <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/instanceof">instanceof</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof">typeof</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/new">new</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this">this</a></code>, and more.</dd>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Reference/Statements">Statements</a></dt>
   <dd>
    Learn how <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/do...while">do-while</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in">for-in</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of">for-of</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch">try-catch</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let">let</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/var">var</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const">const</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if...else">if-else</a></code>, <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/switch">switch</a></code>, and more JavaScript statements and keywords work.</dd>
  </dl>
  <h2 id="Tools_.26_resources">Tools &amp; resources</h2>
  <p>Helpful tools while writing and debugging your JavaScript code.</p>
  <dl>
   <dt>
    <a href="/en-US/docs/Tools">Firefox Developer Tools</a></dt>
   <dd>
    <a href="/en-US/docs/Tools/Scratchpad">Scratchpad</a>, <a href="/en-US/docs/Tools/Web_Console">Web Console</a>, <a href="/en-US/docs/Tools/Profiler">JavaScript Profiler</a>, <a href="/en-US/docs/Tools/Debugger">Debugger</a>, and more.</dd>
   <dt>
    <a class="external" href="https://www.getfirebug.com/">Firebug</a></dt>
   <dd>
    Edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.</dd>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Shells">JavaScript Shells</a></dt>
   <dd>
    A JavaScript shell allows you to quickly test snippets of JavaScript code.</dd>
   <dt>
    <a href="/en-US/docs/Web/JavaScript/Other_JavaScript_tools">Other JavaScript tools</a></dt>
   <dd>
    This article provides a list of additional JavaScript development tools.</dd>
   <dt>
    <a href="https://togetherjs.com/">TogetherJS</a></dt>
   <dd>
    <p class="hero-header-text large">Collaboration made easy.</p>
   </dd>
   <dt>
    <a href="https://stackoverflow.com/questions/tagged/javascript">Stack Overflow</a></dt>
   <dd>
    Stack Overflow questions tagged with "JavaScript".</dd>
  </dl>
 </div>
</div>
<p>{{CommunityBox("JavaScript", "js-engine.internals", "mozilla.dev.tech.js-engine.internals", "js", "ES discuss|https://esdiscuss.org/|esdiscuss.org|ECMAScript standard discussion mailing list||SpiderMonkey|https://wiki.mozilla.org/JavaScript|Project page|Contribute to the JavaScript Engine||Twitter|https://twitter.com/FirefoxNightly|@FirefoxNightly|Firefox Nightly updates on Twitter")}}</p>
<section class="Quick_links" id="Quick_Links">
 <ol>
  <li><a href="/en-US/docs/Web/JavaScript/Tutorials"><strong>Tutorials:</strong></a></li>
  <li data-default-state="closed"><a href="/en-US/docs/Web/JavaScript/Guide">JavaScript Guide</a>
   <ol>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/About">About this Guide</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/JavaScript_Overview">JavaScript Overview</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Values,_variables,_and_literals">Values, variables, and literals</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators">Expressions and operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions">Regular Expressions</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Statements">Statements (Control Flow)</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Functions">Functions</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects">Working with objects</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Predefined_Core_Objects">Predefined Core Objects</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Details_of_the_Object_Model">Details of the object model</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Inheritance_Revisited">Inheritance revisited</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Iterators_and_Generators">Iterators and generators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Closures">Closures</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Sameness">Sameness in JavaScript</a></li>
   </ol>
  </li>
  <li data-default-state="closed"><a href="#">Introductory</a>
   <ol>
    <li><a href="/en-US/docs/Web/JavaScript/Getting_Started">Getting started</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/JavaScript_technologies_overview">JavaScript technologies overview</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Introduction_to_Object-Oriented_JavaScript">Introduction to Object Oriented JavaScript</a></li>
   </ol>
  </li>
  <li data-default-state="closed"><a href="#">Intermediate</a>
   <ol>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript">A re-introduction to JavaScript</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures">JavaScript data structures</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Inheritance_and_the_prototype_chain">Equality comparisons and when to use them</a></li>
   </ol>
  </li>
  <li data-default-state="closed"><a href="#">Advanced</a>
   <ol>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Inheritance_and_the_prototype_chain">Inheritance and the prototype chain</a></li>
    <li><a href="/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/Strict_mode">Strict mode</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays">JavaScript typed arrays</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_Management">Memory Management</a></li>
   </ol>
  </li>
  <li><strong><a href="/en-US/docs/Web/JavaScript/Reference">References:</a></strong></li>
  <li data-default-state="closed"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects">Objects</a>
   <ol>
    <li>{{jsxref("Array")}}</li>
    <li>{{jsxref("ArrayBuffer")}}</li>
    <li>{{jsxref("Boolean")}}</li>
    <li>{{jsxref("DataView")}}</li>
    <li>{{jsxref("Date")}}</li>
    <li>{{jsxref("Error")}}</li>
    <li>{{jsxref("EvalError")}}</li>
    <li>{{jsxref("Float32Array")}}</li>
    <li>{{jsxref("Float64Array")}}</li>
    <li>{{jsxref("Function")}}</li>
    <li>{{jsxref("Int16Array")}}</li>
    <li>{{jsxref("Int32Array")}}</li>
    <li>{{jsxref("Int8Array")}}</li>
    <li>{{jsxref("InternalError")}}</li>
    <li>{{jsxref("Intl")}}</li>
    <li>{{jsxref("Global_Objects/Collator", "Intl.Collator")}}</li>
    <li>{{jsxref("Global_Objects/DateTimeFormat", "Intl.DateTimeFormat")}}</li>
    <li>{{jsxref("Global_Objects/NumberFormat", "Intl.NumberFormat")}}</li>
    <li>{{jsxref("Iterator")}}</li>
    <li>{{jsxref("JSON")}}</li>
    <li>{{jsxref("Map")}}</li>
    <li>{{jsxref("Math")}}</li>
    <li>{{jsxref("Number")}}</li>
    <li>{{jsxref("Object")}}</li>
    <li>{{jsxref("Proxy")}}</li>
    <li>{{jsxref("RangeError")}}</li>
    <li>{{jsxref("ReferenceError")}}</li>
    <li>{{jsxref("RegExp")}}</li>
    <li>{{jsxref("Set")}}</li>
    <li>{{jsxref("StopIteration")}}</li>
    <li>{{jsxref("String")}}</li>
    <li>{{jsxref("SyntaxError")}}</li>
    <li>{{jsxref("TypeError")}}</li>
    <li>{{jsxref("UInt16Array")}}</li>
    <li>{{jsxref("UInt32Array")}}</li>
    <li>{{jsxref("UInt8Array")}}</li>
    <li>{{jsxref("UInt8ClampedArray")}}</li>
    <li>{{jsxref("URIError")}}</li>
    <li>{{jsxref("WeakMap")}}</li>
    <li>{{jsxref("WeakSet")}}</li>
   </ol>
  </li>
  <li data-default-state="closed"><a href="/en-US/docs/Web/JavaScript/Reference/Operators">Operators</a>
   <ol>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators">Arithmetic Operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Assignment_Operators">Assignment Operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators">Bitwise Operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator">Comma Operator</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comparison_Operators">Comparison Operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator">Conditional Operator</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_Operators">Logical Operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence">Operator Precedence</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Member_Operators">Property Accessors</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Special">Special Operators</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_operator">Spread operator</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/String_Operators">String Operators</a></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/delete">delete</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/function">function</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/get">get</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/in">in</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/instanceof">instanceof</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/new">new</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/set">set</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this">this</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof">typeof</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/void">void</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/yield">yield</a></code></li>
   </ol>
  </li>
  <li data-default-state="closed"><a href="/en-US/docs/Web/JavaScript/Reference/Statement">Statements</a>
   <ol>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*">function*</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/block">block</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/break">break</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const">const</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/continue">continue</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/debugger">debugger</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/do...while">do...while</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/export">export</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for">for</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for_each...in">for each...in</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in">for...in</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of">for...of</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function">function</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if...else">if...else</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import">import</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label">label</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let">let</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/return">return</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/switch">switch</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/throw">throw</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch">try...catch</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/var">var</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/while">while</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/with">with</a></code></li>
    <li><code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/yield">yield</a></code></li>
   </ol>
  </li>
  <li><strong><a href="/en-US/docs/MDN">Documentation:</a></strong></li>
  <li data-default-state="closed"><a href="#">Useful lists</a>
   <ol>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Glossary">Glossary</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Index">All pages index</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Methods_Index">Methods index</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Properties_Index">Properties index</a></li>
    <li><a href="https://developer.mozilla.org/en-US/docs/tag/JavaScript">Pages tagged "JavaScript"</a></li>
   </ol>
  </li>
  <li data-default-state="closed"><a href="#">Contribute</a>
   <ol>
    <li><a href="/en-US/docs/MDN/Doc_status/JavaScript">JavaScript doc status</a></li>
    <li><a href="/en-US/docs/MDN/Contribute/Howto/Document_JavaScript">How to document JS</a></li>
   </ol>
  </li>
 </ol>
</section>
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