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+---
+title: Number.NEGATIVE_INFINITY
+slug: Web/JavaScript/Reference/Global_Objects/Number/NEGATIVE_INFINITY
+translation_of: Web/JavaScript/Reference/Global_Objects/Number/NEGATIVE_INFINITY
+---
+<div>
+ {{JSRef("Global_Objects", "Number")}}</div>
+<h2 id="Summary" name="Summary">概述</h2>
+<p><code><strong>Number.NEGATIVE_INFINITY</strong></code> 属性表示负无穷大。</p>
+<p>不用创建一个 {{jsxref("Global_Objects/Number", "Number")}} 实例,使用 <code>Number.NEGATIVE_INFINITY</code> 来访问该静态属性。</p>
+<p>{{js_property_attributes(0,0,0)}}</p>
+<h2 id="Description" name="Description">描述</h2>
+<p><code>Number.NEGATIVE_INFINITY</code> 的值和全局对象的 {{jsxref("Global_Objects/Infinity", "Infinity")}} 属性的负值相同。</p>
+<p>该值的行为同数学上的无穷大(infinity)有一点儿不同:</p>
+<ul>
+ <li>任何正值,包括 <code>POSITIVE_INFINITY,</code>乘以 <code>NEGATIVE_INFINITY</code> 为 <code>NEGATIVE_INFINITY</code>。</li>
+ <li>任何负值,包括 <code>NEGATIVE_INFINITY</code>,乘以 <code>NEGATIVE_INFINITY</code> 为 <code>POSITIVE_INFINITY</code>。</li>
+ <li>0 乘以 <code>NEGATIVE_INFINITY</code> 为 <code>NaN</code>.</li>
+ <li>NaN 乘以 <code>NEGATIVE_INFINITY</code> 为<code> NaN</code>.</li>
+ <li><code>NEGATIVE_INFINITY</code> 除以任何负值(除了 <code>NEGATIVE_INFINITY)</code>为 <code>POSITIVE_INFINITY</code>。</li>
+ <li><code>NEGATIVE_INFINITY</code> 除以任何正值(除了 <code>POSITIVE_INFINITY</code>)为 <code>NEGATIVE_INFINITY</code>。</li>
+ <li><code>NEGATIVE_INFINITY</code> 除以 <code>NEGATIVE_INFINITY</code> 或 <code>POSITIVE_INFINITY</code> 是 <code>NaN</code>。</li>
+ <li>任何数除以 <code>NEGATIVE_INFINITY</code> 为 0。</li>
+</ul>
+<p>为了成功返回一个有限值,你可能会使用 <code>Number.NEGATIVE_INFINITY</code> 属性来判断是否显示一个条件错误 。然而 {{jsxref("Global_Objects/isFinite", "isFinite")}} 方法更适合这种情况。</p>
+<h2 id="Example" name="Example">示例</h2>
+<p>下例中,赋值给变量 <code>smallNumber</code> 一个明显小于 JavaScript 中的最小值的值。当 <code>if</code> 语句执行时,<code>smallNumber</code> 值为 "<code>-Infinity</code>",因此在继续执行代码前,<code>smallNumber</code> 被设为一个更容易管理的值。</p>
+<pre class="brush:js">var smallNumber = (-Number.MAX_VALUE) * 2
+
+if (smallNumber == Number.NEGATIVE_INFINITY) {
+ smallNumber = returnFinite();
+}
+</pre>
+<h2 id="规范">规范</h2>
+<table class="standard-table">
+ <tbody>
+ <tr>
+ <th scope="col">Specification</th>
+ <th scope="col">Status</th>
+ <th scope="col">Comment</th>
+ </tr>
+ <tr>
+ <td>ECMAScript 1st Edition. Implemented in JavaScript 1.1</td>
+ <td>Standard</td>
+ <td>Initial definition.</td>
+ </tr>
+ <tr>
+ <td>{{SpecName('ES5.1', '#sec-15.7.3.5', 'Number.NEGATIVE_INFINITY')}}</td>
+ <td>{{Spec2('ES5.1')}}</td>
+ <td> </td>
+ </tr>
+ <tr>
+ <td>{{SpecName('ES6', '#sec-number.negative_infinity', 'Number.NEGATIVE_INFINITY')}}</td>
+ <td>{{Spec2('ES6')}}</td>
+ <td> </td>
+ </tr>
+ </tbody>
+</table>
+<h2 id="浏览器规范">浏览器规范</h2>
+<p>{{ CompatibilityTable() }}</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>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</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>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ <td>{{ CompatVersionUnknown() }}</td>
+ </tr>
+ </tbody>
+ </table>
+</div>
+<h2 id="See_also" name="See_also">相关链接</h2>
+<ul>
+ <li>{{jsxref("Number.POSITIVE_INFINITY")}}</li>
+ <li>{{jsxref("Global_Objects/Infinity", "Infinity")}}</li>
+ <li>{{jsxref("Global_Objects/isFinite", "isFinite")}}</li>
+</ul>