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  1. Web
  2. JavaScript
  3. Reference
  4. Standard built-in objects
  5. Number
  6. valueOf()

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.

ThevalueOf() method ofNumber 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: 42console.log(typeof num);// Expected output: "number"

Syntax

js
valueOf()

Parameters

None.

Return value

A number representing the primitive value of the specifiedNumber 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); // objectconst num = numObj.valueOf();console.log(num); // 10console.log(typeof num); // number

Specifications

Specification
ECMAScript® 2026 Language Specification
# sec-number.prototype.valueof

Browser compatibility

See also

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