Number.parseInt()

The Number.parseInt() method parses a string argument and returns an integer of the specified radix or base.

Syntax

JavaScript
Number.parseInt(<var>string</var>[, <var>radix</var>])

Parameters

string
The value to parse. If string is not a string, then it is converted to a string (using the ToString abstract operation). Leading whitespace in the string is ignored.
radix
An integer between 2 and 36 that represents the radix (the base in mathematical numeral systems) of the above mentioned string. Specify 10 for the decimal numeral system commonly used by humans. Always specify this parameter to eliminate reader confusion and to guarantee predictable behavior. Different implementations produce different results when a radix is not specified, usually defaulting the value to 10.

Return value

An integer number parsed from the given string. If the first character cannot be converted to a number, NaN is returned.

Description

This method has the same functionality as the global parseInt() function:

JavaScript
Number.parseInt === parseInt; // true

and is part of ECMAScript 2015 (its purpose is modularization of globals). Please see parseInt() for more details and examples.

Polyfill

JavaScript
Number.parseInt = parseInt;

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Number.parseInt' in that specification.
Standard Initial definition.
ECMAScript 2017 Draft (ECMA-262)
The definition of 'Number.parseInt' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 25 (25) No support (Yes) No support
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support 25 (25) No support No support No support

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/number/parseint

ECMAScript6 JavaScript Method Number