(PHP 4 >= 4.0.4)

is_null --  Finds whether a variable is NULL


bool is_null ( mixed var)

Returns TRUE if var is null, FALSE otherwise.

See the NULL type when a variable is considered to be NULL and when not.

See also NULL, is_bool(), is_numeric(), is_float(), is_int(), is_string(), is_object(), is_array(), is_integer(), and is_real().