files/zh-cn/web/javascript/reference/global_objects/number/isinteger/index.html


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---
title: Number.isInteger()
slug: Web/JavaScript/Reference/Global_Objects/Number/isInteger
tags:
  - JavaScript
  - Method
  - Number
  - Reference
  - 方法
translation_of: Web/JavaScript/Reference/Global_Objects/Number/isInteger
---
<div>{{JSRef}}</div>

<p><strong><code>Number.isInteger()</code></strong> 方法用来判断给定的参数是否为整数。</p>

<p>{{EmbedInteractiveExample("pages/js/number-isinteger.html")}}</p>

<h2 id="Syntax" name="Syntax">语法</h2>

<pre class="syntaxbox"><code>Number.isInteger(v<var>alue</var>)</code></pre>

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

<dl>
 <dt><code>value</code></dt>
 <dd>要判断此参数是否为整数</dd>
</dl>

<h3 id="返回值">返回值</h3>

<p>判断给定值是否是整数的 {{jsxref("Boolean")}} 值。</p>

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

<p>如果被检测的值是整数，则返回 <code>true</code>，否则返回 <code>false</code>。注意 {{jsxref("Global_Objects/NaN", "NaN")}} 和正负 {{jsxref("Global_Objects/Infinity", "Infinity")}} 不是整数。</p>

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

<pre class="brush: js">Number.isInteger(0);         // true
Number.isInteger(1);         // true
Number.isInteger(-100000);   // true

Number.isInteger(0.1);       // false
Number.isInteger(Math.PI);   // false

Number.isInteger(Infinity);  // false
Number.isInteger(-Infinity); // false
Number.isInteger("10");      // false
Number.isInteger(true);      // false
Number.isInteger(false);     // false
Number.isInteger([1]);       // false</pre>

<h2 id="Polyfill" name="Polyfill">Polyfill</h2>

<pre class="brush: js">Number.isInteger = Number.isInteger || function(value) {
    return typeof value === "number" &amp;&amp;
           isFinite(value) &amp;&amp;
           Math.floor(value) === value;
};
</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>{{SpecName('ES6', '#sec-number.isinteger', 'Number.isInteger')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td>Initial definition.</td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-number.isinteger', 'Number.isInteger')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td></td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility" name="Browser_compatibility">浏览器兼容性</h2>

<p>{{Compat("javascript.builtins.Number.isInteger")}}</p>

<h2 id="See_also" name="See_also">相关链接</h2>

<ul>
 <li>{{jsxref("Global_Objects/Number", "Number")}}</li>
</ul>