PHP is_nan() Function

Definition and Usage

is_nan() determines whether it is a valid number.

Syntax

is_nan(x)
Parameter Description
x Required. Specifies the value to be checked.

Description

If x Returns true for 'non-numeric', such as the result of acos(1.01).

Example

<?php
echo is_nan(200);
echo is_nan(acos(1.01));
?>

Output:

1