PHP is_nan () function
Examples
Determine whether a non-numeric value:
<?php
echo is_nan(200) . "<br>";
echo is_nan(acos(1.01));
?>
echo is_nan(200) . "<br>";
echo is_nan(acos(1.01));
?>
Running instance »
Definition and Usage
is_nan () function to determine whether a non-numeric value.
If the value of non-designated value, the function returns true (1). Otherwise, it returns false / nothing.
grammar
is_nan( value );
参数 | 描述 |
---|---|
value | 必需。规定要检查的值。 |
technical details
return value: | If a non-numeric value, it returns TRUE. Otherwise, it returns FALSE. |
---|---|
Return type: | Boolean |
PHP version: | 4.2+ |
PHP Math Reference