Php/docs/function.is-nan
From Get docs
is_nan
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
is_nan — Finds whether a value is not a number
Description
is_nan
( float $val
) : bool
Checks whether val is 'not a number',
like the result of acos(1.01).
Parameters
val- The value to check
Return Values
Returns TRUE if val is 'not a number',
else FALSE.
Examples
Example #1 is_nan() example
<?php// Invalid calculation, will return a // NaN value$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
