Variable handling Functions
PHP Manual

is_null

(PHP 4 >= 4.0.4, PHP 5)

is_null Finds whether a variable is NULL

Description

bool is_null ( mixed $var )

Finds whether the given variable is NULL.

Parameters

var

The variable being evaluated.

Return Values

Returns TRUE if var is null , FALSE otherwise.

Examples

Example #1 is_null() example

<?php

error_reporting
(E_ALL);

$foo NULL;
var_dump(is_null($inexistent), is_null($foo));

?>
Notice: Undefined variable: inexistent in ...
bool(true)
bool(true)

See Also


Variable handling Functions
PHP Manual