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The valueOf() method returns the wrapped primitive value of a Number object.

Syntax

numObj.valueOf()

Return value

A number representing the primitive value of the specified Number object.

Description

This method is usually called internally by JavaScript and not explicitly in web code.

Examples

Using valueOf

var numObj = new Number(10);
console.log(typeof numObj); // object

var num = numObj.valueOf();
console.log(num);           // 10
console.log(typeof num);    // number

Specifications

Specification Status Comment
ECMAScript 1st Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.1.
ECMAScript 5.1 (ECMA-262)
The definition of 'Number.prototype.valueOf' in that specification.
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Number.prototype.valueOf' in that specification.
Standard  
ECMAScript Latest Draft (ECMA-262)
The definition of 'Number.prototype.valueOf' in that specification.
Draft  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes1 Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes4 Yes Yes Yes

See also

Document Tags and Contributors

Những người đóng góp cho trang này: wbamberg, fscholz, jameshkramer, eduardoboucas, ziyunfei, Mingun, ethertank, Sheppy, evilpie, Waldo, Potappo, Mgjbot
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