---
title: JavaScript の新機能
slug: Web/JavaScript/New_in_JavaScript
translation_of: Archive/Web/JavaScript/New_in_JavaScript
---
<div>{{jsSidebar("New_in_JS")}}</div>

<p>このページはJavaScriptバージョン履歴の情報とFirefoxのようなMozilla/SpiderMonkeyベースのJavaScriptアプリケーションの実装状況を表示します。</p>

<h2 id="ECMAScript_versions">ECMAScript versions</h2>

<dl>
 <dt><a href="/en-US/docs/Web/JavaScript/Language_Resources">Language resources</a></dt>
 <dd>JavaScript言語の標準になっている、ECMAScript standardsを学ぶことが出来ます。</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/ECMAScript_5_support_in_Mozilla">ECMAScript 5 support</a></dt>
 <dd>Mozillaベースのエンジン（RhinoやSpidermonkeyなど）や製品におけるECMA-262 Edition 5.1の実装状況を表します。</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/ECMAScript_6_support_in_Mozilla">ECMAScript 6 support</a></dt>
 <dd>Mozillaベースのエンジン（RhinoやSpidermonkeyなど）や製品におけるECMA-262 Edition 6の実装状況を表します。</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/ECMAScript_7_support_in_Mozilla">ECMAScript 7 support</a></dt>
 <dd>Mozillaベースのエンジン（RhinoやSpidermonkeyなど）や製品におけるECMA-262 Edition 7の実装状況を表します。</dd>
</dl>

<h2 id="JavaScript_リリースノート">JavaScript リリースノート</h2>

<dl>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/Firefox_JavaScript_changelog">Firefox JavaScript changelog</a></dt>
 <dd>Firefox5とそれ以降のJavaScriptのチェンジログについてはこの項目を参照してください。</dd>
 <dt> </dt>
 <dt>Chrome JavaScript changelog</dt>
 <dd>(TODO). See this changelog for JavaScript features implemented in Chrome releases.</dd>
</dl>

<h2 id="JavaScript_versions">JavaScript versions</h2>

<p><strong>Deprecated</strong> ({{deprecated_inline()}}). The explicit versioning and opt-in of language features was Mozilla-specific and <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=867609">is in process of being removed</a>. Firefox 4 was the last version which referred to an JavaScript version (1.8.5). With new ECMA standards, JavaScript language features are now often mentioned with their initial definition in ECMA-262 Editions such as Edition 6 (ES6).</p>

<p>JavaScript was released as version 1.0 in March 1996 in Netscape Navigator 2.0 and Internet Explorer 2.0.</p>

<dl>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.1">JavaScript 1.1</a></dt>
 <dd>Version shipped in Netscape Navigator 3.0. Released on August 19, 1996.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.2">JavaScript 1.2</a></dt>
 <dd>Version shipped in Netscape Navigator 4.0-4.05. Released on June 11, 1997.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.3">JavaScript 1.3</a></dt>
 <dd>Version shipped in Netscape Navigator 4.06-4.7x. Released on October 19, 1998.<br>
 Standardization work to be compliant with ECMA-262 1st and 2nd Edition.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.4">JavaScript 1.4</a></dt>
 <dd>Version shipped in Netscape's server side JavaScript. Released in 1999.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.5">JavaScript 1.5</a></dt>
 <dd>Version shipped in Netscape Navigator 6.0 and Firefox 1.0. Release on November 14, 2000.<br>
 標準化団体の ECMA-262 3rd Editionに準拠しています。</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.6">JavaScript 1.6</a></dt>
 <dd>Version shipped in Firefox 1.5. Released in November 2005.<br>
 ECMAScript for XML (E4X)やnew <code>Array</code> methods plus <code>String</code> and <code>Array</code> generics.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.7">JavaScript 1.7</a></dt>
 <dd>Version shipped in Firefox 2. Released in October 2006.<br>
 Includes generators, iterators, array comprehensions, <code>let</code> expressions, and destructuring assignment.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.8">JavaScript 1.8</a></dt>
 <dd>Version shipped in Firefox 3. Released in June 2008.<br>
 Includes expression closures, generator expressions and <code>Array.reduce()</code></dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.8.1">JavaScript 1.8.1</a></dt>
 <dd>Version shipped in Firefox 3.5. Released on <span class="st">June 30, 2009.<br>
 Includes the TraceMonkey JIT and supports native JSON.</span></dd>
 <dt>JavaScript 1.8.2</dt>
 <dd>Version shipped in Firefox 3.6. Released June 22, 2009.<br>
 Includes only minor changes.</dd>
 <dt><a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.8.5">JavaScript 1.8.5</a></dt>
 <dd>Version shipped in Firefox 4. Released July 27, 2010.<br>
 Includes many new features for ECMA-262 Edition 5 compliance.<br>
 This is the last JavaScript version.</dd>
</dl>

<h2 id="Features_still_requiring_version_opt-in">Features still requiring version opt-in</h2>

<dl>
 <dt><a href="/en-US/docs/Web/JavaScript/Reference/Statements/let"><code>let</code> statement</a></dt>
 <dd>The <code>let</code> statement requires the JavaScript version 1.7 (or higher) opt-in. See {{bug(932517)}} and {{bug(932513)}}.</dd>
</dl>