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<article id="wikiArticle">
<div></div>
<p><strong><code>Number.isFinite()</code></strong> 方法用来检测传入的参数是否是一个有穷数finite number</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre><code class="language-javascript"><code>Number.isFinite(v<var>alue</var>)</code></code></pre>
<h3 id="Parameters" name="Parameters">参数</h3>
<dl>
<dt><code>value</code></dt>
<dd>要被检测有穷性的值。</dd>
<dt>
<h3 id="返回值">返回值</h3>
<p>一个 <a href="Reference/Boolean" title="此页面仍未被本地化, 期待您的翻译!"><code>布尔值</code></a> 表示给定的值是否是一个有穷数。</p>
</dt>
</dl>
<h2 id="描述">描述</h2>
<p>和全局的 <a href="Reference/Global_Objects/isFinite" title="该全局 isFinite() 函数用来判断被传入的参数值是否为一个有限数值finite number。在必要情况下参数会首先转为一个数值。"><code>isFinite()</code></a> 函数相比这个方法不会强制将一个非数值的参数转换成数值这就意味着只有数值类型的值且是有穷的finite才返回 <code>true</code></p>
<h2 id="示例">示例</h2>
<pre><code class="language-javascript">Number.isFinite(Infinity); // false
Number.isFinite(NaN); // false
Number.isFinite(-Infinity); // false
Number.isFinite(0); // true
Number.isFinite(2e64); // true
Number.isFinite('0'); // false, 全局函数 isFinite('0') 会返回 true
</code></pre>
<h2 id="Polyfill">Polyfill</h2>
<pre><code class="language-javascript">Number.isFinite = Number.isFinite || function(value) {
    return typeof value === "number" &amp;&amp; isFinite(value);
}
</code></pre>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范名称</th>
<th scope="col">规范状态</th>
<th scope="col">备注</th>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-number.isfinite" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Number.isInteger</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-number.isfinite" hreflang="en" lang="en" rel="noopener">ECMAScript Latest Draft (ECMA-262)<br/><small lang="zh-CN">Number.isInteger</small></a></td>
<td><span class="spec-Draft">Draft</span></td>
<td> </td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility" name="Browser_compatibility">浏览器兼容性</h2>
<div><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></div>
<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>19</td>
<td><a href="/en-US/Firefox/Releases/16" title="Released on 2012-10-09.">16</a> (16)</td>
<td><span style="color: #f00;">未实现</span></td>
<td>15</td>
<td>9</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: rgb(255, 153, 0);" title="Compatibility unknown; please update this.">?</span></td>
<td><span style="color: rgb(255, 153, 0);" title="Compatibility unknown; please update this.">?</span></td>
<td>16.0 (16)</td>
<td><span style="color: rgb(255, 153, 0);" title="Compatibility unknown; please update this.">?</span></td>
<td><span style="color: rgb(255, 153, 0);" title="Compatibility unknown; please update this.">?</span></td>
<td><span style="color: rgb(255, 153, 0);" title="Compatibility unknown; please update this.">?</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/Number" title="JavaScript 的 Number 对象是经过封装的能让你处理数字值的对象。Number 对象由 Number() 构造器创建。"><code>Number</code></a></li>
</ul>
</article>