注: empty() is a language construct.
This is the opposite of (boolean)
var, except that no
warning is generated when the variable is not set. See
converting to boolean for more information.
$var = 0; if (empty($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.