empty
Description
bool empty ( mixed var)empty() returns FALSE if var has a non-empty or non-zero value. In otherwords, "", 0, "0", NULL , FALSE , array(), var $var;, and objects with empty properties, are all considered empty. TRUE is returned if var is empty.
empty() 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.
Example 1. A simple empty() / isset() comparison.
<?php
$var = 0;
// Evaluates to true because $var is empty
if (empty($var)) {
echo '$var is either 0, empty, or not set at all';
}
// Evaluates as true because $var is set
if (isset($var)) {
echo '$var is set even though it is empty';
}
?>
Note: Because this is a language construct and not a function, it cannot be called using variable functions
Note: empty() only checks variables as anything else will result in a parse error. In otherwords, the following will not work: empty(addslashes($name)).
See also isset(), unset(), array_key_exists(), count(), strlen(), and the type comparison tables.
