---
title: Math.cbrt()
slug: Web/JavaScript/Reference/Global_Objects/Math/cbrt
translation_of: Web/JavaScript/Reference/Global_Objects/Math/cbrt
---
<div>{{JSRef("Global_Objects", "Math")}}</div>

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

<p><code><strong>Math.cbrt()</strong></code> 函数返回任意数字的立方根.</p>

<h2 id="Syntax" name="Syntax">语法</h2>

<pre class="syntaxbox">Math.cbrt(<em>x</em>)</pre>

<h3 id="Parameters" name="Parameters">参数</h3>

<dl>
 <dt><code>x</code></dt>
 <dd>任意数字.</dd>
</dl>

<h3 id="返回值">返回值</h3>



<p>给定数字的立方根</p>



<h2 id="Description" name="Description">描述</h2>

<p>该方法为Math的静态方法,因此请直接通过Math.cbrt()方式调用.</p>

<p>而不是作为您创建的Math对象的方法(Math不是构造函数)。</p>

<p><span style="font-family: 'Courier New','Andale Mono',monospace; font-weight: inherit; line-height: normal;">cbrt 是 "cube root" 的缩写, 意思是立方根.</span></p>

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

<h3 id="使用_Math.cbrt">使用 Math.cbrt()</h3>

<pre class="brush: js">Math.cbrt(NaN); // NaN
Math.cbrt(-1); // -1
Math.cbrt(-0); // -0
Math.cbrt(-Infinity); // -Infinity
Math.cbrt(0); // 0
Math.cbrt(1); // 1
Math.cbrt(Infinity); // Infinity
Math.cbrt(null); // 0
Math.cbrt(2);  // 1.2599210498948734</pre>

<h2 id="Polyfill"><font face="consolas, Liberation Mono, courier, monospace"><span style="background-color: rgba(220, 220, 220, 0.5);">Polyfill</span></font></h2>

<p>为了与旧版浏览器兼容, 可使用下方函数模拟cbrt():</p>

<pre class="brush: js" dir="rtl">if (!Math.cbrt) {
  Math.cbrt = function(x) {
    var y = Math.pow(Math.abs(x), 1/3);
    return x &lt; 0 ? -y : y;
  };
}</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('ES6', '#sec-math.cbrt', 'Math.cbrt')}}</td>
   <td>{{Spec2('ES6')}}</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>

<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>{{CompatNo}}</td>
   <td>{{CompatGeckoDesktop("25")}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for 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>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatGeckoMobile("25")}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>



<h2 id="另请参见">另请参见</h2>

<ul>
 <li>{{jsxref("Math.pow()")}}</li>
 <li>{{jsxref("Math.sqrt()")}}</li>
</ul>