JavaScript Number parseInt() method

Definition and usage

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

radix The parameter specifies the numerical system to be used:

2 = Binary, 8 = Octal, 10 = Decimal, 16 = Hexadecimal.

If omitted radix, JavaScript assumes a base of 10. If the value starts with "0x", JavaScript assumes a base of 16.

Note:

If the first character cannot be converted to a number, it returns NaN.

Leading and trailing spaces will be ignored.

It only returns the first integer found.

Instance

Example 1

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

Example 2

Number.parseInt("10", 10);
Number.parseInt("010");
Number.parseInt("10", 8);
Number.parseInt("0x10");
Number.parseInt("10", 16);

Try it yourself

Syntax

Number.parseInt(string, radix)

Parameter

Parameter Description
value Required. The value to be parsed.
radix

Optional. The default is 10.

Specifies the numerical system of the value (2 to 36).

Return value

Type Description
Boolean value If an integer is not found, it returns NaN.

Browser support

Number.parseInt() It is ECMAScript6 (ES6) features.

All modern browsers support ES6 (JavaScript 2015):

Chrome Edge Firefox Safari Opera
Chrome Edge Firefox Safari Opera
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Internet Explorer 11 (eller tidigare versioner) stöder inte Number.parseInt().