---
title: Document.documentElement
slug: Web/API/Document/documentElement
translation_of: Web/API/Document/documentElement
---
<p>{{ ApiRef("DOM") }}</p>

<p><code><strong>Document.documentElement</strong></code> 會回傳目前文件（{{domxref("document")}}）中的根元素（{{domxref("Element")}}），如：HTML 文件中的 <code>&lt;html&gt;</code> 元素。</p>

<h2 id="Syntax" name="Syntax">語法</h2>

<pre class="syntaxbox">var <em>element</em> = document.documentElement;
</pre>

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

<pre class="brush:js">var rootElement = document.documentElement;
var firstTier = rootElement.childNodes;

// firstTier is the NodeList of the direct children of the root element
for (var i = 0; i &lt; firstTier.length; i++) {
   // do something with each direct kid of the root element
   // as firstTier[i]
}</pre>

<h2 id="Notes" name="Notes">備註</h2>

<p>對於所有非空的 HTML 文件， <code>document.documentElement</code> 將會是一個 {{HTMLElement("html")}}  元素 ; 對於所有非空的 XML 文件，<code>document.documentElement</code> 則會是文件的根元素。</p>

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

<table class="spectable standard-table">
 <tbody>
  <tr>
   <th scope="col">規範</th>
   <th scope="col">狀態</th>
   <th scope="col"> 備註</th>
  </tr>
  <tr>
   <td>{{SpecName('DOM2 Core','core.html#ID-87CD092','Document.documentElement')}}</td>
   <td>{{Spec2('DOM2 Core')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM3 Core','core.html#ID-87CD092','Document.documentElement')}}</td>
   <td>{{Spec2('DOM3 Core')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM4','#dom-document-documentelement','Document.documentElement')}}</td>
   <td>{{Spec2('DOM4')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM WHATWG','#dom-document-documentelement','Document.documentElement')}}</td>
   <td>{{Spec2('DOM WHATWG')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>