Boolean.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 Boolean values returns the primitive value of a Boolean object.

Try it

const x = new Boolean();

console.log(x.valueOf());
// Expected output: false

const y = new Boolean("Mozilla");

console.log(y.valueOf());
// Expected output: true

Syntax

valueOf()

Parameters

None.

Return value

The primitive value of the given Boolean object.

Description

The valueOf() method of Boolean returns the primitive value of a Boolean object or literal Boolean as a Boolean data type.

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

Examples

Using valueOf()

js
const x = new Boolean();
const myVar = x.valueOf(); // assigns false to myVar

Specifications

Specification

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

Browser compatibility

Enable JavaScript to view this browser compatibility table.

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This page was last modified on Jul 10, 2025 by MDN contributors.

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Standard built-in objects
Boolean
Constructor
1. Boolean()
Instance methods
1. toString()
2. valueOf()
Inheritance
Object/Function
Static methods
Static properties
Instance methods
Instance properties
1. __proto__
2. constructor