目录

JavaScript Number.parseInt()

Examples

Number.parseInt("10");
Number.parseInt("10.00");
Number.parseInt("10.33");
Number.parseInt("34 45 66");
Number.parseInt(" 60 ");
Number.parseInt("40 years");
Number.parseInt("He was 40");
Try it Yourself »
Number.parseInt("10", 10);
Number.parseInt("010");
Number.parseInt("10", 8);
Number.parseInt("0x10");
Number.parseInt("10", 16);
Try it Yourself »

Description

The Number.parseInt method parses a value as a string and returns the first integer.

A radix parameter specifies the number system to use:

2 = binary, 8 = octal, 10 = decimal, 16 = hexadecimal.

If radix is omitted, JavaScript assumes radix 10. If the value begins with "0x", JavaScript assumes radix 16.

Notes

If the first character cannot be converted, NaN is returned.

Leading and trailing spaces are ignored.

Only the first integer found is returned.


Syntax

Number.parseInt( string, radix)

Parameters

Parameter Description
value Required.
The value to be parsed.
radix Optional. Default is 10.
A number (2 to 36) specifying the number system.

Return Value

Type Description
Number NaN if no integer is found.


Browser Support

Number.parseInt() is an ECMAScript6 (ES6) feature.

ES6 (JavaScript 2015) is supported in all modern browsers:

Chrome Edge Firefox Safari Opera
Yes Yes Yes Yes Yes

Number.parseInt() is not supported in Internet Explorer 11 (or earlier).