JavaScript Global method: parseInt()
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The JavaScript
Global
parseInt() method parses a
string returns an integer where practical. If the first available non-space
character of x is not numerical then the method returns NaN. Only the first of multiple
numbers will be returned.
It
has the following syntax with the following parameters:
parseInt(x, radix)
|
Parameter
|
Required / Optional
|
Description
|
|
x
|
Required
|
String corresponding to
the input number
|
|
radix
|
Optional
|
An integer between 2
and 36 specifying the radix, i.e. number base, used in forming the integer
from the strong. See below if omitted
|
Users are recommended to
include a radix as the results can otherwise vary by browser. Usually, if the
radix is omitted and x begins with “0x” (maybe “Ox”) then the radix
(number base) is taken to be 16. If it begins with “0” (maybe “O”) then the
radix is base 8 (this option is depreciated), otherwise usually the radix is
defaulted to base 10 (i.e. decimal). The method finds the first character in x
after leading spaces, works out if this is one that can appear in a number and
then continues parsing the string until it reaches the end of any part that is
interpretable as a number, returning that number as a number value, not a
string.
EXAMPLE:
HTML USED IN THIS EXAMPLE:
<!DOCTYPE html>
<html> <!-- Copyright (c) Nematrian Limited 2018 -->
<head>
<style>
table,th,tr,td {border: 1px solid black; border-collapse :collapse;}
</style>
</head>
<body>
<table>
<tr>
<th>Example</th>
<th>Resulting value of <code>x</code></th>
</tr>
<tr>
<td><code id="Example"></code></td>
<td><code id="Result"></code></td>
</tr>
<tr>
<td><code id="Example2"></code></td>
<td><code id="Result2"></code></td>
</tr>
</table>
<script>
document.getElementById("Example").innerHTML =
'var x = parseInt(" 3, 4");';
document.getElementById("Result").innerHTML =
parseFloat(" 3, 4");
document.getElementById("Example2").innerHTML =
'var x2 = parseFloat(" a3, 4");';
document.getElementById("Result2").innerHTML =
parseFloat(" a3, 4");
</script>
</body>
</html>
|
FUNCTION THAT MAY ASSIST IN TESTING WHETHER FEATURE IS SUPPORTED:
function isSupportedJavaScriptMethodGlobalParseInt() {
return (parseInt("3") == 3);
} |
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