is_nan
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
is_nan — Finds whether a value is not a number
Description
is_nan(float $num): bool
Checks whether num is 'not a number', like the result of acos(1.01).
Parameters
-
num -
The value to check
Return Values
Returns true if num is 'not a number', else false.
Examples
Example #1 is_nan() example
<?php // Invalid calculation, will return a // NaN value $nan = acos(8); var_dump($nan, is_nan($nan)); ?>
The above example will output:
float(NAN) bool(true)
See Also
- is_finite() - Finds whether a value is a legal finite number
- is_infinite() - Finds whether a value is infinite
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.is-nan.php
