From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- .../global_objects/number/valueof/index.html | 122 +++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html (limited to 'files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html') diff --git a/files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html b/files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html new file mode 100644 index 0000000000..81168e6ea0 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html @@ -0,0 +1,122 @@ +--- +title: Number.prototype.valueOf() +slug: Web/JavaScript/Reference/Global_Objects/Number/valueOf +tags: + - JavaScript + - Method + - Number + - valueOf() +translation_of: Web/JavaScript/Reference/Global_Objects/Number/valueOf +--- +
{{JSRef("Global_Objects", "Number")}}
+ +

概述

+ +

valueOf() 方法返回一个被 {{jsxref("Global_Objects/Number", "Number")}} 对象包装的原始值。

+ +

语法

+ +
numObj.valueOf()
+ +

返回值

+ +

表示指定 {{jsxref("Number")}} 对象的原始值的数字

+ +

描述

+ +

该方法通常是由 JavaScript 引擎在内部隐式调用的,而不是由用户在代码中显式调用的。

+ +

示例

+ +
var numObj = new Number(10);
+console.log(typeof numObj); // object
+
+var num = numObj.valueOf();
+console.log(num);           // 10
+console.log(typeof num);    // number
+
+ +

规范

+ + + + + + + + + + + + + + + + + + + + + + + + +
规范名称规范状态备注
ECMAScript 1st Edition.Standard 
{{SpecName('ES5.1', '#sec-15.7.4.4', 'Number.prototype.valueOf')}}{{Spec2('ES5.1')}} 
{{SpecName('ES6', '#sec-number.prototype.valueof', 'Number.prototype.valueOf')}}{{Spec2('ES6')}} 
+ +

浏览器兼容性

+ +
{{CompatibilityTable}}
+ +
+ + + + + + + + + + + + + + + + + + + +
FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}
+
+ +
+ + + + + + + + + + + + + + + + + + + + + +
FeatureAndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}
+
+ +

相关链接

+ + -- cgit v1.2.3-54-g00ecf