uTools-Manuals/docs/javascript/Reference/Global_Objects/Math/max.html

<article id="wikiArticle">
<div></div>
<p><code><strong>Math.max()</strong></code> 函数返回一组数中的最大值。</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre><code class="language-javascript"><code>Math.max(<em>value1</em>[,<em>value2</em>, ...]) </code></code></pre>
<h3 id="Parameters" name="Parameters">参数</h3>
<dl>
<dt><code>value1, value2, ...</code></dt>
<dd>一组数值</dd>
</dl>
<h3 id="返回值">返回值</h3>
<p>返回给定的一组数字中的最大值。如果给定的参数中至少有一个参数无法被转换成数字，则会返回 <a href="Reference/Global_Objects/NaN" title="全局属性 NaN 的值表示不是一个数字（Not-A-Number）。"><code>NaN</code></a>。</p>
<h2 id="Description" name="Description">描述</h2>
<p>由于 <code>max</code> 是 <code>Math</code> 的静态方法，所以应该像这样使用：<code>Math.max()</code>，而不是作为你创建的 <code>Math</code> 实例的方法(Math并非一个构造体)。</p>
<p>如果没有参数，则结果为 - <a href="Reference/Global_Objects/Infinity" title="全局属性 Infinity 是一个数值，表示无穷大。"><code>Infinity</code></a>。</p>
<p>如果有任一参数不能被转换为数值，则结果为 <a href="Reference/Global_Objects/NaN" title="全局属性 NaN 的值表示不是一个数字（Not-A-Number）。"><code>NaN</code></a>。</p>
<h2 id="Examples" name="Examples">示例</h2>
<h3 id="Example:_Using_Math.max" name="Example:_Using_Math.max">使用 <code>Math.max()</code></h3>
<pre><code  class="language-javascript">Math.max(10, 20);   //  20
Math.max(-10, -20); // -10
Math.max(-10, 20);  //  20
</code></pre>
<p>下面的方法使用 <a href="Reference/Global_Objects/Function/apply" title="apply() 方法调用一个具有给定this值的函数，以及作为一个数组（或类似数组对象）提供的参数。"><code>apply</code></a> 方法寻找一个数值数组中的最大元素。<code>getMaxOfArray([1,2,3])</code> 等价于 <code>Math.max(1, 2, 3)</code>，但是你可以使用 <code>getMaxOfArray</code> ()作用于任意长度的数组上。</p>
<pre><code class="language-js">function getMaxOfArray(numArray) {
    return Math.max.apply(null, numArray);
}
</code></pre>
<p>或者通过使用最新的扩展语句<a href="Reference/Operators/Spread_operator" title="REDIRECT Spread syntax"><code>spread operator</code></a>，获得数组中的最大值变得更容易。</p>
<pre><code  class="language-javascript">var arr = [1, 2, 3];
var max = Math.max(...arr);
</code></pre>
<p> </p>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范版本</th>
<th scope="col">规范状态</th>
<th scope="col">注解</th>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%201st%20edition,%20June%201997.pdf" hreflang="en" lang="en" rel="noopener" title="ECMAScript 1st Edition (ECMA-262)">ECMAScript 1st Edition (ECMA-262)</a></td>
<td><span class="spec-Standard">Standard</span></td>
<td>Initial definition. Implemented in JavaScript 1.0.</td>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/ecma-262/5.1/#sec-15.8.2.11" hreflang="en" lang="en" rel="noopener">ECMAScript 5.1 (ECMA-262)<br/><small lang="zh-CN">Math.max</small></a></td>
<td><span class="spec-Standard">Standard</span></td>
<td> </td>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-math.max" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Math.max</small></a></td>
<td><span class="spec-Standard">Standard</span></td>
<td> </td>
</tr>
<tr>
<td><a class="external" href="https://tc39.github.io/ecma262/#sec-math.max" hreflang="en" lang="en" rel="noopener">ECMAScript Latest Draft (ECMA-262)<br/><small lang="zh-CN">Math.max</small></a></td>
<td><span class="spec-Draft">Draft</span></td>
<td> </td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<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>.
            This compatibility table still uses the old format,
            because we haven't yet converted the data it contains.
            <strong><a class="new" href="/zh-CN/docs/MDN/Contribute/Structures/Compatibility_tables" rel="nofollow">Find out how you can help!</a></strong></div>
<div class="htab">
<a id="AutoCompatibilityTable" name="AutoCompatibilityTable"></a>
<ul>
<li class="selected"><a>Desktop</a></li>
<li><a>Mobile</a></li>
</ul>
</div><p></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><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></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><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
</tr>
</tbody>
</table>
</div>
<h2 id="See_also" name="See_also">相关链接</h2>
<ul>
<li><a href="Reference/Global_Objects/Math/min" title="Math.min() 返回零个或更多个数值的最小值。"><code>Math.min()</code></a></li>
</ul>
</article>