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 September 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.
radixOptional-
An integer between
2and36that represents the radix (the base in mathematical numeral systems) of thestring.If
radixis undefined or0, it is assumed to be10except when the number begins with the code unit pairs0xor0X, in which case a radix of16is 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® 2027 Language Specification # sec-number.parseint |