Number.prototype.valueOf()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The valueOf() method of Number values returns the value of this number.

Try it

const numObj = new Number(42);
console.log(typeof numObj);
// Expected output: "object"

const num = numObj.valueOf();
console.log(num);
// Expected output: 42

console.log(typeof num);
// Expected output: "number"

Syntax

js
valueOf()

Parameters

None.

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

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

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

Specifications

Specification
ECMAScript® 2027 Language Specification
# sec-number.prototype.valueof

Browser compatibility

desktop mobile server
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Bun
Deno
Node.js
valueOf
Chrome – Full support
Chrome 1 (Release date: 2008-12-11)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 1 (Release date: 2004-11-09)
footnote Full support
Opera – Full support
Opera 4 (Release date: 2000-06-28)
footnote Full support
Safari – Full support
Safari 1 (Release date: 2003-06-23)
footnote Full support
Chrome Android – Full support
Chrome Android 18 (Release date: 2012-06-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 4 (Release date: 2011-03-29)
footnote Full support
Opera Android – Full support
Opera Android 10.1 (Release date: 2010-11-09)
footnote Full support
Safari on iOS – Full support
Safari on iOS 1 (Release date: 2007-06-29)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1 (Release date: 2013-04-27)
footnote Full support
WebView Android – Full support
WebView Android 4.4 (Release date: 2013-12-09)
footnote Full support
WebView on iOS – Full support
WebView on iOS 1 (Release date: 2007-06-29)
footnote Full support
Bun – Full support
Bun 1 (Release date: 2023-09-08)
footnote Full support
Deno – Full support
Deno 1 (Release date: 2020-05-13)
footnote Full support
Node.js – Full support
Node.js 0.10 (Release date: 2013-03-11)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also