Returns false if var is set and has a non-empty or non-zero value; true otherwise.
$var = 0; if (empty($var)) { // evaluates true echo '$var is either 0 or not set at all'; } if (!isset($var)) { // evaluates false echo '$var is not set at all'; } |
Note that this is meaningless when used on anything which isn't a variable; i.e. empty (addslashes ($name)) has no meaning since it would be checking whether something which isn't a variable is a variable with a false value.