bool empty ( mixed $var )
Determine whether a variable is considered to be empty.
Returns FALSE if var has a non-empty and non-zero value. The following things are considered to be empty: "" (an empty string) 0 (0 as an integer) 0.0 (0 as a float) "0" (0 as a string) NULL FALSE array() (an empty array) var $var; (a variable declared, but without a value in a class)