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diff --git a/files/zh-cn/web/javascript/reference/global_objects/number/isfinite/index.html b/files/zh-cn/web/javascript/reference/global_objects/number/isfinite/index.html new file mode 100644 index 0000000000..aef163cfb6 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/global_objects/number/isfinite/index.html @@ -0,0 +1,89 @@ +--- +title: Number.isFinite() +slug: Web/JavaScript/Reference/Global_Objects/Number/isFinite +tags: + - Experimental + - JavaScript + - Method + - Number + - Reference +translation_of: Web/JavaScript/Reference/Global_Objects/Number/isFinite +--- +<div>{{JSRef}}</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。</p> + +<p>{{EmbedInteractiveExample("pages/js/number-isfinite.html")}}</p> + +<h2 id="Syntax" name="Syntax">语法</h2> + +<pre class="syntaxbox notranslate"><code>Number.isFinite(v<var>alue</var>)</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> +</dl> + +<h3 id="返回值">返回值</h3> + +<p>一个 {{jsxref("Boolean", "布尔值")}} 表示给定的值是否是一个有穷数。</p> + +<h2 id="描述">描述</h2> + +<p>和全局的 {{jsxref("Global_Objects/isFinite", "isFinite()")}} 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="Polyfill">Polyfill</h2> + +<pre class="brush: js notranslate">if (Number.isFinite === undefined) Number.isFinite = function(value) { + return typeof value === 'number' && isFinite(value); +}</pre> + +<h2 id="示例">示例</h2> + +<pre class="brush: js notranslate">Number.isFinite(Infinity); // false +Number.isFinite(NaN); // false +Number.isFinite(-Infinity); // false + +Number.isFinite(0); // true +Number.isFinite(2e64); // true + +Number.isFinite('0'); // false, would've been true with + // global isFinite('0') +Number.isFinite(null); // false, would've been true with + // global isFinite(null) +</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.isfinite', 'Number.isInteger')}}</td> + <td>{{Spec2('ES6')}}</td> + <td></td> + </tr> + <tr> + <td>{{SpecName('ESDraft', '#sec-number.isfinite', '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> + +<div>{{Compat("javascript.builtins.Number.isFinite")}}</div> + +<h2 id="See_also" name="See_also">相关链接</h2> + +<ul> + <li>The {{jsxref("Number")}} object it belongs to.</li> + <li>The global function {{jsxref("isFinite")}}.</li> +</ul> |
