Description
bool
empty ( mixed var)
empty() returns FALSE if
var has a non-empty and 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 '$var is set even though it is empty';
}
?>
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Note: Because this is a
language construct and not a function, it cannot be called using
variable functions
Note:
empty() only checks variables as anything else will
result in a parse error. In otherwords, the following will not work:
empty(addslashes($name)).
See also isset(),
unset(),
array_key_exists(),
count(),
strlen(), and
the type comparison tables.
