JavaScript parseInt() Function
Complete Function Reference
Definition and Usage
The parseInt() function parses a string and returns an integer.
The radix parameter is used to specify which numeral system to be used, for
example, a radix of 16 (hexadecimal) indicates that the number in the string
should be parsed from a hexadecimal number to a decimal number.
If the radix parameter is omitted, JavaScript assumes the
following:
- If the string begins with "0x", the radix is 16 (hexadecimal)
- If the string begins with "0", the radix is 8 (octal). This
feature is deprecated
- If the string begins with any other value, the radix is 10 (decimal)
Syntax
| Parameter |
Description |
| string |
Required. The string to be parsed |
| radix |
Optional. A number (from 2 to 36) that represents the
numeral system to be used |
Tips and Notes
Note: Only the first number in the string is returned!
Note: Leading and trailing spaces are allowed.
Note: If the first character cannot be converted to a number,
parseInt() returns NaN.
Example
In this example we will use parseInt() to parse different strings:
<script type="text/javascript">
document.write(parseInt("10") + "<br />");
document.write(parseInt("10.00") + "<br />");
document.write(parseInt("10.33") + "<br />");
document.write(parseInt("34 45 66") + "<br />");
document.write(parseInt(" 60 ") + "<br />");
document.write(parseInt("40 years") + "<br />");
document.write(parseInt("He was 40") + "<br />");
document.write("<br />");
document.write(parseInt("10")+ "<br />");
document.write(parseInt("10",10)+ "<br />");
document.write(parseInt("010")+ "<br />");
document.write(parseInt("10",8)+ "<br />");
document.write(parseInt("0x10")+ "<br />");
document.write(parseInt("10",16)+ "<br />");
</script>
|
The output of the code above will be:
10
10
10
34
60
40
NaN
10
10
8
8
16
16
|
Try it yourself »
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