---
title: AudioBuffer.length
slug: Web/API/AudioBuffer/length
translation_of: Web/API/AudioBuffer/length
---
<p>{{ APIRef("Web Audio API") }}</p>

<div>
<p>The <code>length</code> property of the {{ domxref("AudioBuffer") }} interface returns an integer representing the length, in sample-frames, of the PCM data stored in the buffer.</p>

<p>{{ domxref("AudioBuffer") }} 的length属性接口返回整数，该整数代表采样帧中，存贮在缓冲区中的PCM数据的长度</p>
</div>

<h2 id="语法">语法</h2>

<pre class="brush: js;highlight[22]">var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);
myArrayBuffer.length;</pre>

<h3 id="值">值</h3>

<p>浮点数</p>

<h2 id="例子">例子</h2>

<pre class="brush: js;highlight[22]">// Stereo
var channels = 2;

// Create an empty two second stereo buffer at the
// sample rate of the AudioContext
var frameCount = audioCtx.sampleRate * 2.0;
var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);

button.onclick = function() {
  // Fill the buffer with white noise;
  // just random values between -1.0 and 1.0
  for (var channel = 0; channel &lt; channels; channel++) {
    // This gives us the actual ArrayBuffer that contains the data
    var nowBuffering = myArrayBuffer.getChannelData(channel);
    for (var i = 0; i &lt; frameCount; i++) {
      // Math.random() is in [0; 1.0]
      // audio needs to be in [-1.0; 1.0]
      nowBuffering[i] = Math.random() * 2 - 1;
    }
  }

  console.log(myArrayBuffer.length);
}</pre>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Web Audio API', '#widl-AudioBuffer-length', 'length')}}</td>
   <td>{{Spec2('Web Audio API')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<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>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari (WebKit)</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>14 {{property_prefix("webkit")}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>23</td>
   <td>{{CompatNo}}</td>
   <td>15 {{property_prefix("webkit")}}<br>
    22 (unprefixed)</td>
   <td>6 {{property_prefix("webkit")}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>Firefox OS</th>
   <th>IE Phone</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatNo}}</td>
   <td>28 {{property_prefix("webkit")}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>25</td>
   <td>1.2</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>6 {{property_prefix("webkit")}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Web/API/Web_Audio_API/Using_Web_Audio_API">Using the Web Audio API</a></li>
</ul>