---
title: Element.className
slug: Web/API/Element/className
tags:
  - Element.className
translation_of: Web/API/Element/className
---
<div>{{APIRef("DOM")}}</div>

<h2 id="Summary" name="Summary">概述</h2>

<p><strong>className</strong> 获取或设置指定元素的class属性的值。</p>

<h2 id="Syntax" name="Syntax">语法</h2>

<pre class="syntaxbox"><var>let cName</var> = <var>elementNodeReference</var>.className;

<var>elementNodeReference</var>.className = <var>cName</var>;</pre>

<ul>
 <li><var>cName</var>是一个字符串变量,表示当前元素的<code>class</code>属性的值,可以是由空格分隔的多个<code>class</code>属性值.</li>
</ul>

<h2 id="Example" name="Example">示例</h2>

<pre class="brush: js">let elm = document.getElementById("div1");

if (elm.className == "fixed") {
  // 跳过class属性为特定值的元素
  goNextElement();
}</pre>

<h2 id="Notes" name="Notes">注释</h2>

<div class="note">
<p>使用名称<code>className</code>而不是<code>class</code>作为属性名,是因为"class" 在JavaScript中是个保留字.</p>
</div>

<h2 id="Specification" name="Specification">规范</h2>

<ul>
 <li><a href="http://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-95362176">DOM Level 2 HTML: className</a></li>
</ul>

<table>
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName("DOM WHATWG", "#dom-element-classname", "element.className")}}</td>
   <td>{{Spec2("DOM WHATWG")}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName("DOM4", "#dom-element-classname", "element.className")}}</td>
   <td>{{Spec2("DOM4")}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName("DOM2 HTML", "html.html#ID-95362176", "element.className")}}</td>
   <td>{{Spec2("DOM2 HTML")}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<p>{{CompatibilityTable}}</p>

<table>
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>

<table>
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>

<h2 id="相关链接">相关链接</h2>

<ul>
 <li>{{domxref("element.classList")}}</li>
</ul>