---
title: Node.prefix
slug: Web/API/Node/prefix
translation_of: Web/API/Node/prefix
---
<div>
 {{ApiRef}}</div>
<h2 id="Summary" name="Summary">概述</h2>
<p><code>prefix属性会</code>返回当前节点的命名空间前缀,如果没有指定命名空间前缀,则返回<code>null</code>,该属性只读.</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre class="syntaxbox"><var>string</var> = element.prefix
</pre>
<h2 id="Examples" name="Examples">示例</h2>
<p>下面的代码将弹出"x".</p>
<pre class="brush:xml">&lt;x:div onclick="alert(this.prefix)"/&gt;
</pre>
<h2 id="Notes" name="Notes">附注</h2>
<p>该属性只在一个解析命名空间前缀的文档中可用,也就是说,只有在文档的MIME类型为XML,XHTML,XUL时可用,在HTML文档中不可用.</p>
<h2 id="Specification" name="Specification">规范</h2>
<ul>
 <li><a href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/core.html#ID-NodeNSPrefix">Node.prefix</a> (introduced in DOM2)</li>
</ul>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<div>
 {{CompatibilityTable}}</div>
<div id="compat-desktop">
 <table class="compat-table">
  <tbody>
   <tr>
    <th>Feature</th>
    <th>Chrome</th>
    <th>Firefox (Gecko)</th>
    <th>Internet Explorer</th>
    <th>Opera</th>
    <th>Safari</th>
   </tr>
   <tr>
    <td>Basic support</td>
    <td>{{CompatUnknown}}</td>
    <td>
     <p>{{CompatVersionUnknown}}</p>
     <p>在Gecko 5.0 (Firefox 5.0 / Thunderbird 5.0 / SeaMonkey 2.2)之前,该属性是可写的; 之后,是只读的.</p>
    </td>
    <td>{{CompatUnknown}}</td>
    <td>{{CompatUnknown}}</td>
    <td>{{CompatUnknown}}</td>
   </tr>
  </tbody>
 </table>
</div>
<div id="compat-mobile">
 <table class="compat-table">
  <tbody>
   <tr>
    <th>Feature</th>
    <th>Android</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>{{CompatUnknown}}</td>
    <td>
     <p>{{CompatVersionUnknown}}</p>
     <p>P在Gecko 5.0 (Firefox 5.0 / Thunderbird 5.0 / SeaMonkey 2.2)之前,该属性是可写的; 之后,是只读的.</p>
    </td>
    <td>{{CompatUnknown}}</td>
    <td>{{CompatUnknown}}</td>
    <td>{{CompatUnknown}}</td>
   </tr>
  </tbody>
 </table>
</div>
<p></p>