Number.parseInt

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

Syntax

Number.parseInt(string,[ radix ])

Parameters

string

The value to parse. If the string argument is not a string, then it is converted to a string (using the ToString abstract operation). Leading whitespace in the string argument 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:

Number.parseInt === parseInt; // true

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

Polyfill

if (Number.parseInt === undefined)
    Number.parseInt = window.parseInt;

Specifications

Browser compatibility

See also

• The Number object it belongs to.
• The global parseInt() method.