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126 lines
5.1 KiB
HTML
126 lines
5.1 KiB
HTML
<article id="wikiArticle">
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<div>
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</div>
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<h2 id="Summary" name="Summary">概述</h2>
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<p><code><strong>Number.MIN_VALUE</strong></code> 属性表示在 JavaScript 中所能表示的最小的正值。</p>
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<p></p><table class="standard-table">
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<thead>
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<tr>
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<th class="header" colspan="2"><code>Number.MIN_VALUE</code> 属性的属性特性：</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>writable</td>
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<td>false</td>
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</tr>
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<tr>
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<td>enumerable</td>
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<td>false</td>
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</tr>
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<tr>
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<td>configurable</td>
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<td>false</td>
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</tr>
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</tbody>
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</table><p></p>
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<h2 id="Description" name="Description">描述</h2>
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<p><code>MIN_VALUE</code> 属性是 JavaScript 里最接近 0 的正值，而不是最小的负值。</p>
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<p><code>MIN_VALUE</code> 的值约为 5e-324。小于 <code>MIN_VALUE</code> ("underflow values") 的值将会转换为 0。</p>
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<p>因为 <code>MIN_VALUE</code> 是 <code>Number</code> 的一个静态属性，因此应该直接使用： <code>Number.MIN_VALUE，</code> 而不是作为一个创建的 <code>Number</code> 实例的属性。</p>
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<h2 id="Examples" name="Examples">示例</h2>
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<h3 id="Example:_Using_MIN_VALUE" name="Example:_Using_MIN_VALUE">例子：使用 <code>MIN_VALUE</code></h3>
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<p>下面的代码里两个数值相除。如果结果大于或等于 <code>MIN_VALUE</code>，则调用 <code>func1</code> 函数；否则，调用 <code>func2</code> 函数。</p>
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<pre><code class="language-js">if (num1 / num2 >= Number.MIN_VALUE) {
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func1();
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} else {
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func2();
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}</code></pre>
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<h2 id="规范">规范</h2>
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<table class="standard-table">
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<tbody>
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<tr>
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<th scope="col">规范版本</th>
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<th scope="col">规范状态</th>
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<th scope="col">注解</th>
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</tr>
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<tr>
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<td>ECMAScript 1st Edition. Implemented in JavaScript 1.1</td>
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<td>Standard</td>
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<td>Initial definition.</td>
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</tr>
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<tr>
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<td><a class="external" href="https://www.ecma-international.org/ecma-262/5.1/#sec-15.7.3.3" hreflang="en" lang="en" rel="noopener">ECMAScript 5.1 (ECMA-262)<br/><small lang="zh-CN">Number.MIN_VALUE</small></a></td>
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<td><span class="spec-Standard">Standard</span></td>
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<td> </td>
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</tr>
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<tr>
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<td><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-number.min_value" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Number.MIN_VALUE</small></a></td>
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<td><span class="spec-Standard">Standard</span></td>
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<td> </td>
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</tr>
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</tbody>
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</table>
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<h2 id="浏览器兼容性">浏览器兼容性</h2>
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<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>.
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This compatibility table still uses the old format,
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because we haven't yet converted the data it contains.
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<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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<div class="htab">
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<a id="AutoCompatibilityTable" name="AutoCompatibilityTable"></a>
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<ul>
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<li class="selected"><a>Desktop</a></li>
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<li><a>Mobile</a></li>
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</ul>
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</div><p></p>
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<div id="compat-desktop">
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<table class="compat-table">
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<tbody>
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<tr>
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<th>Feature</th>
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<th>Chrome</th>
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<th>Firefox (Gecko)</th>
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<th>Internet Explorer</th>
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<th>Opera</th>
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<th>Safari</th>
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</tr>
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<tr>
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<td>Basic support</td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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</tr>
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</tbody>
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</table>
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</div>
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<div id="compat-mobile">
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<table class="compat-table">
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<tbody>
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<tr>
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<th>Feature</th>
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<th>Android</th>
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<th>Chrome for Android</th>
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<th>Firefox Mobile (Gecko)</th>
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<th>IE Mobile</th>
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<th>Opera Mobile</th>
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<th>Safari Mobile</th>
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</tr>
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<tr>
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<td>Basic support</td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
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</tr>
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</tbody>
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</table>
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</div>
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<h2 id="See_also" name="See_also">相关链接</h2>
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<ul>
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<li><a href="Reference/Global_Objects/Number/MAX_VALUE" title="Number.MAX_VALUE 属性表示在 JavaScript 里所能表示的最大数值。"><code>Number.MAX_VALUE</code></a></li>
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</ul>
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</article> |