uTools-Manuals/docs/javascript/Reference/Global_Objects/Number/MAX_VALUE.html

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<h2 id="Summary" name="Summary">概述</h2>
<p><code><strong>Number.MAX_VALUE</strong></code> 属性表示在 JavaScript 里所能表示的最大数值。</p>
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<th class="header" colspan="2"><code>Number.MAX_VALUE</code> 属性的属性特性：</th>
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<td>writable</td>
<td>false</td>
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<td>enumerable</td>
<td>false</td>
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<td>configurable</td>
<td>false</td>
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<h2 id="Description" name="Description">描述</h2>
<p><code>MAX_VALUE</code> 属性值接近于 <code>1.79E+308</code>。大于 <code>MAX_VALUE</code> 的值代表 "<code>Infinity</code>"。</p>
<p>因为 <code>MAX_VALUE</code> 是 <code>Number</code> 对象的一个静态属性，所以你应该直接使用<code>Number.MAX_VALUE</code> ，而不是作为一个创建的 <code>Number</code> 实例的属性。</p>
<h2 id="Examples" name="Examples">示例</h2>
<h3 id="Example:_Using_MAX_VALUE" name="Example:_Using_MAX_VALUE">例子：使用 <code>MAX_VALUE</code></h3>
<p>下面的代码求两个数值的乘积。如果结果小于等于 <code>MAX_VALUE</code>，则调用 <code>func1</code> 函数；否则，调用 <code>func2</code> 函数。</p>
<pre><code  class="language-javascript">if (num1 * num2 &lt;= Number.MAX_VALUE) {
   func1();
} else {
   func2();
}</code></pre>
<h2 id="规范">规范</h2>
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<th scope="col">规范版本</th>
<th scope="col">规范状态</th>
<th scope="col">注解</th>
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<td>ECMAScript 1st Edition. Implemented in JavaScript 1.1</td>
<td>Standard</td>
<td>Initial definition.</td>
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<td><a class="external" href="https://www.ecma-international.org/ecma-262/5.1/#sec-15.7.3.2" hreflang="en" lang="en" rel="noopener">ECMAScript 5.1 (ECMA-262)<br/><small lang="zh-CN">Number.MAX_VALUE</small></a></td>
<td><span class="spec-Standard">Standard</span></td>
<td> </td>
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<td><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-number.max_value" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Number.MAX_VALUE</small></a></td>
<td><span class="spec-Standard">Standard</span></td>
<td> </td>
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<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>
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<a id="AutoCompatibilityTable" name="AutoCompatibilityTable"></a>
<ul>
<li class="selected"><a>Desktop</a></li>
<li><a>Mobile</a></li>
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<th>Feature</th>
<th>Chrome</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
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<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>
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<div id="compat-mobile">
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<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>
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<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>
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<h2 id="See_also" name="See_also">相关链接</h2>
<ul>
<li><a href="Reference/Global_Objects/Number/MIN_VALUE" title="Number.MIN_VALUE 属性表示在 JavaScript 中所能表示的最小的正值。"><code>Number.MIN_VALUE</code></a></li>
</ul>
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