PHP: is_nan function

Description

The is_nan() function is used to find whether a value is not a number.

Version

(PHP 4 and above)

Syntax:

is_nan (num)

Parameter:

Return value:

TRUE if val is not a number otherwise FALSE.

Value Type : Boolean.

Pictorial Presentation:

Example:

<?php
$nval1=10.21;
$nval2=acos(1.02);
$nval3=500;
$zisf1=is_nan($nval1);
$zisf2=is_nan($nval2);
$zisf3=is_nan($nval3);
echo "$nval1 is is_nan : $zisf1<br />";
echo "$nval2 is is_nan : $zisf2<br />";
echo "$nval3 is is_nan : $zisf3<br />";
?>

Output:

10.21 is is_nan :
NAN is is_nan : 1
500 is is_nan : 

View the example in the browser

See also

PHP Function Reference

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