2019-04-21 11:50:48 +08:00

112 lines
5.3 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<article id="wikiArticle">
<div>
</div>
<h2 id="Summary" name="Summary">概述</h2>
<p><code><strong>Math.exp()</strong></code> 函数返回 <code>e<sup>x</sup></code><code>x</code> 表示参数,<code>e</code><a href="Reference/Global_Objects/Math/E">欧拉常数Euler's constant</a>,自然对数的底数。</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre><code class="language-javascript"><code>Math.exp(<em>x</em>)</code></code></pre>
<h3 id="Parameters" name="Parameters">参数</h3>
<dl>
<dt>
<code>x</code></dt>
<dd>
一个数值</dd>
</dl>
<h2 id="Description" name="Description">描述</h2>
<p>由于 <code>exp</code><code>Math</code> 的静态方法,所以应该像这样使用:<code>Math.exp()</code>,而不是作为你创建的 <code>Math</code> 实例的方法。</p>
<h2 id="Examples" name="Examples">示例</h2>
<h3 id="Example:_Using_Math.exp" name="Example:_Using_Math.exp">例子:使用 <code>Math.exp</code></h3>
<pre><code class="language-js">Math.exp(-1); // 0.36787944117144233
Math.exp(0); // 1
Math.exp(1); // 2.718281828459045</code></pre>
<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>ECMAScript 1st Edition. Implemented in JavaScript 1.0</td>
<td>Standard</td>
<td>Initial definition.</td>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/ecma-262/5.1/#sec-15.8.2.8" hreflang="en" lang="en" rel="noopener">ECMAScript 5.1 (ECMA-262)<br/><small lang="zh-CN">Math.exp</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.exp" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Math.exp</small></a></td>
<td><span class="spec-Standard">Standard</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>The <a href="Reference/Global_Objects/Math" title="Math 是一个内置对象 它具有数学常数和函数的属性和方法。不是一个函数对象。"><code>Math</code></a> object it belongs to.</li>
<li><a href="Reference/Global_Objects/Math/E" title="Math.E 属性表示自然对数的底数或称为基数e约等于 2.718。"><code>Math.E</code></a></li>
<li><a href="Reference/Global_Objects/Math/log" title="Math.log() 函数返回一个数的自然对数,即:"><code>Math.log()</code></a></li>
<li><a href="Reference/Global_Objects/Math/pow" title="Math.pow() 函数返回基数base的指数exponent次幂 baseexponent。"><code>Math.pow()</code></a></li>
</ul>
</article>