Determine whether a variable is empty
Syntax
empty ( mixed $var ) : bool
Parameters
var
Variable to be checked
No warning is generated if the variable does not exist. That means empty() is essentially the concise equivalent to !isset($var) || $var == false.
Return
Returns FALSE if var exists and has a non-empty, non-zero value. Otherwise returns TRUE.
The following values 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)
Examples
1
<? $var = 0; $return = empty($var); echo $return; ?>
1
2
<? // $var does not exist $return = empty($var); echo $return; ?>
1
3
<?
echo empty("") . PHP_EOL;
echo empty(0) . PHP_EOL;
echo empty(0.0) . PHP_EOL;
echo empty("0") . PHP_EOL;
echo empty(null) . PHP_EOL;
echo empty(false) . PHP_EOL;
echo empty(array());
?>
1 1 1 1 1 1 1
4
<? $expected_array_got_string = "abc"; var_dump(empty($expected_array_got_string[0])); var_dump(empty($expected_array_got_string[0.0])); var_dump(empty($expected_array_got_string["0"])); var_dump(empty($expected_array_got_string["0.0"])); var_dump(empty($expected_array_got_string["0 abc"])); var_dump(empty($expected_array_got_string["abc"])); ?>
bool(false) bool(false) bool(false) bool(true) bool(true) bool(true)
