String.prototype.valueOf()

The valueOf() method returns the primitive value of a String object.

Syntax

JavaScript
<var>str</var>.valueOf()

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()

JavaScript
var x = new String('Hello world');
console.log(x.valueOf()); // Displays 'Hello world'

Specifications

Specification Status Comment
ECMAScript 1st Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.1.
ECMAScript 5.1 (ECMA-262)
The definition of 'String.prototype.valueOf' in that specification.
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'String.prototype.valueOf' in that specification.
Standard  
ECMAScript 2017 Draft (ECMA-262)
The definition of 'String.prototype.valueOf' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/string/valueof

JavaScript Method Prototype Reference String