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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

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

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® 2026 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`	1	12	1	4	1	18	4	10.1	1	1.0	4.4	1	1.0.0	1.0	0.10.0