is_nan
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
is_nan — Finds whether a value is not a number
Description
bool is_nan ( mixed $val ) 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
← is_infinite
lcg_value →
? 1997–2017 The PHP Documentation GroupLicensed under the Creative Commons Attribution License v3.0 or later.
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