Number.parseInt()
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 Number.parseInt()
static method parses a string argument and returns an integer of the specified radix or base.
Try it
function roughScale(x, base) { const parsed = Number.parseInt(x, base); if (Number.isNaN(parsed)) { return 0; } return parsed * 100; } console.log(roughScale(" 0xF", 16)); // Expected output: 1500 console.log(roughScale("321", 2)); // Expected output: 0
Syntax
Number.parseInt(string) Number.parseInt(string, radix)
Parameters
string
The value to parse, coerced to a string. Leading whitespace in this argument is ignored.
radix
OptionalAn integer between
2
and36
that represents the radix (the base in mathematical numeral systems) of thestring
.If
radix
is undefined or0
, it is assumed to be10
except when the number begins with the code unit pairs0x
or0X
, in which case a radix of16
is assumed.
Return value
An integer parsed from the given string
.
If the radix
is smaller than 2
or bigger than 36
, or the first non-whitespace character cannot be converted to a number, NaN
is returned.
Examples
Number.parseInt vs. parseInt
This method has the same functionality as the global parseInt()
function:
Number.parseInt === parseInt; // true
Its purpose is modularization of globals. Please see parseInt()
for more detail and examples.
Specifications
Specification |
---|
ECMAScript® 2026 Language Specification # sec-number.parseint |