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114 lines
4.3 KiB
HTML
114 lines
4.3 KiB
HTML
<article id="wikiArticle">
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<div></div>
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<h2 id="Summary" name="Summary">概述</h2>
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<p><code><strong>Math.cbrt()</strong></code> 函数返回任意数字的立方根.</p>
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<h2 id="Syntax" name="Syntax">语法</h2>
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<pre><code class="language-javascript">Math.cbrt(<em>x</em>)</code></pre>
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<h3 id="Parameters" name="Parameters">参数</h3>
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<dl>
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<dt><code>x</code></dt>
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<dd>任意数字.</dd>
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</dl>
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<h2 id="Description" name="Description">描述</h2>
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<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>
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<p>参数 <code>x</code> 会被自动类型转换成 <code>number </code>类型.</p>
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<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>
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<h2 id="Examples" name="Examples">示例</h2>
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<pre><code class="language-javascript">Math.cbrt(NaN); // NaN
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Math.cbrt(-1); // -1
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Math.cbrt(-0); // -0
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Math.cbrt(-Infinity); // -Infinity
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Math.cbrt(0); // 0
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Math.cbrt(1); // 1
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Math.cbrt(Infinity); // Infinity
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Math.cbrt(null); // 0
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Math.cbrt(2); // 1.2599210498948734</code></pre>
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<h2 id="Polyfill"><font face="consolas, Liberation Mono, courier, monospace"><span style="background-color: rgba(220, 220, 220, 0.5);">Polyfill</span></font></h2>
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<p>为了与旧版浏览器兼容, 可使用下方函数模拟cbrt():</p>
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<pre><code class="language-js" dir="rtl">if (!Math.cbrt) {
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Math.cbrt = function(x) {
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var y = Math.pow(Math.abs(x), 1/3);
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return x < 0 ? -y : y;
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};
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}</code></pre>
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<h2 id="规范">规范</h2>
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<table class="standard-table">
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<tbody>
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<tr>
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<th scope="col">Specification</th>
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<th scope="col">Status</th>
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<th scope="col">Comment</th>
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</tr>
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<tr>
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<td><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-math.cbrt" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Math.cbrt</small></a></td>
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<td><span class="spec-Standard">Standard</span></td>
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<td>Initial definition.</td>
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</tr>
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</tbody>
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</table>
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<h2 id="浏览器兼容性">浏览器兼容性</h2>
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<p></p><div class="blockIndicator warning"><strong><a class="external" href="https://github.com/mdn/browser-compat-data" rel="noopener">We're converting our compatibility data into a machine-readable JSON format</a></strong>.
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This compatibility table still uses the old format,
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because we haven't yet converted the data it contains.
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<strong><a class="new" href="/zh-CN/docs/MDN/Contribute/Structures/Compatibility_tables" rel="nofollow">Find out how you can help!</a></strong></div>
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<div class="htab">
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<a id="AutoCompatibilityTable" name="AutoCompatibilityTable"></a>
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<ul>
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<li class="selected"><a>Desktop</a></li>
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<li><a>Mobile</a></li>
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</ul>
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</div><p></p>
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<div id="compat-desktop">
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<table class="compat-table">
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<tbody>
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<tr>
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<th>Feature</th>
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<th>Chrome</th>
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<th>Firefox (Gecko)</th>
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<th>Internet Explorer</th>
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<th>Opera</th>
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<th>Safari</th>
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</tr>
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<tr>
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<td>Basic support</td>
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<td><span style="color: #f00;">未实现</span></td>
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<td><a href="/en-US/Firefox/Releases/25" title="Released on 2013-10-29.">25</a> (25)</td>
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<td><span style="color: #f00;">未实现</span></td>
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<td><span style="color: #f00;">未实现</span></td>
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<td><span style="color: #f00;">未实现</span></td>
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</tr>
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</tbody>
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</table>
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</div>
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<div id="compat-mobile">
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<table class="compat-table">
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<tbody>
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<tr>
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<th>Feature</th>
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<th>Android</th>
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<th>Chrome for Android</th>
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<th>Firefox Mobile (Gecko)</th>
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<th>IE Mobile</th>
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<th>Opera Mobile</th>
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<th>Safari Mobile</th>
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</tr>
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<tr>
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<td>Basic support</td>
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<td><span style="color: #f00;">未实现</span></td>
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<td><span style="color: #f00;">未实现</span></td>
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<td>25.0 (25)</td>
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<td><span style="color: #f00;">未实现</span></td>
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<td><span style="color: #f00;">未实现</span></td>
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<td><span style="color: #f00;">未实现</span></td>
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</tr>
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</tbody>
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</table>
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</div>
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<p> </p>
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<h2 id="另请参见">另请参见</h2>
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<ul>
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<li><a href="Reference/Global_Objects/Math/pow" title="Math.pow() 函数返回基数（base）的指数（exponent）次幂，即 baseexponent。"><code>Math.pow()</code></a></li>
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<li><a href="Reference/Global_Objects/Math/sqrt" title="Math.sqrt() 函数返回一个数的平方根，即："><code>Math.sqrt()</code></a></li>
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</ul>
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<p> </p>
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</article> |