---
title: Document.body
slug: Web/API/Document/body
translation_of: Web/API/Document/body
---
<div>{{APIRef("DOM")}}</div>

<p>回傳目前文件的 {{HTMLElement("body")}} 或 {{HTMLElement("frameset")}} 節點，如元素不存在則回傳 <code>null</code>。</p>

<h2 id="Syntax" name="Syntax">語法</h2>

<pre class="syntaxbox"><em>var objRef</em> = document.body;
document.body = <em>objRef;</em></pre>

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

<pre class="brush:js">// in HTML: &lt;body id="oldBodyElement"&gt;&lt;/body&gt;
alert(document.body.id); // "oldBodyElement"

var aNewBodyElement = document.createElement("body");

aNewBodyElement.id = "newBodyElement";
document.body = aNewBodyElement;
alert(document.body.id); // "newBodyElement"
</pre>

<h2 id="Notes" name="Notes">備註</h2>

<p><code>document.body</code> is the element that contains the content for the document. In documents with <code>&lt;body&gt;</code> contents, returns the <code>&lt;body&gt;</code> element, and in frameset documents, this returns the outermost <code>&lt;frameset&gt;</code> element.</p>

<p>Though <code>body</code> is settable, setting a new body on a document will effectively remove all the current children of the existing <code>&lt;body&gt;</code> element.</p>

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

<table class="spectable standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('HTML WHATWG','dom.html#dom-document-body','Document.body')}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('HTML5.1','dom.html#dom-document-body','Document.body')}}</td>
   <td>{{Spec2('HTML5.1')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('HTML5 W3C','dom.html#dom-document-body','Document.body')}}</td>
   <td>{{Spec2('HTML5 W3C')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM2 HTML','html.html#ID-56360201','Document.body')}}</td>
   <td>{{Spec2('DOM2 HTML')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM1','level-one-html.html#attribute-body','Document.body')}}</td>
   <td>{{Spec2('DOM1')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="瀏覽器相容性">瀏覽器相容性</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-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>1</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>2</td>
   <td>6</td>
   <td>9.6 (possibly earlier)</td>
   <td>4 (possibly earlier)</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>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>5 (probably earlier)</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="參見">參見</h2>

<ul>
 <li>{{domxref("document.head")}}</li>
</ul>