String.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 String values returns this string value.

Try it

const stringObj = new String("foo");
console.log(stringObj);
// Expected output: String { "foo" }
console.log(stringObj.valueOf());
// Expected output: "foo"

Syntax

js
valueOf()

Parameters

None.

Return value

A string representing the primitive value of a given String object.

Description

The valueOf() method of String returns the primitive value of a String object as a string data type. This value is equivalent to String.prototype.toString().

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

Examples

Using valueOf()

js
const x = new String("Hello world");
console.log(x.valueOf()); // 'Hello world'

Specifications

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

Browser compatibility

See also