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empty

Description

The empty of Variable Handling for PHP 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. This also applies to nested structures, such as a multidimensional array or chained properties.

Return

Returns true if var does not exist or has a value that is empty or equal to zero, aka falsey, otherwise returns false.

ValueDescription
null
false
""an empty string
array()an empty array
00 as an integer
0.00 as a float
"0"0 as a string

Examples

1 · does not exist

<?

$return = empty($var);

var_export($return);

true

2 · null

<?

$var = null;

$return = empty($var);

var_export($return);

true

3 · false

<?

$var = false;

$return = empty($var);

var_export($return);

true

4 · empty · string

<?

$var = "";

$return = empty($var);

var_export($return);

true

5 · empty · array

<?

$var = [];

$return = empty($var);

var_export($return);

true

6 · 0 · integer

<?

$var = 0;

$return = empty($var);

var_export($return);

true

7 · 0 · float

<?

$var = 0.0;

$return = empty($var);

var_export($return);

true

8 · 0 · string

<?

$var = "0";

$return = empty($var);

var_export($return);

true

9 · string offset

<?

$string = "string";

var_dump(empty($string[0]));
var_dump(empty($string[0.0]));
var_dump(empty($string["0"]));
var_dump(empty($string[6]));
var_dump(empty($string[6.0]));
var_dump(empty($string["6"]));
var_dump(empty($string["0.0"]));
var_dump(empty($string["6.0"]));
var_dump(empty($string["0 string"]));
var_dump(empty($string["string"]));

bool(false)
bool(false)
bool(false)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

10 · multidimensional array

<?

$array =
[
    "key1" =>
    [
        "key2" =>
        [
            "key3" => "value"
        ]
    ]
];

var_dump(empty($array));
var_dump(empty($array["key1"]));
var_dump(empty($array["key1"]["key2"]));
var_dump(empty($array["key1"]["key2"]["key3"]));
var_dump(empty($array[""]));
var_dump(empty($array["key1"][""]));
var_dump(empty($array["key1"]["key2"][""]));

bool(false)
bool(false)
bool(false)
bool(false)
bool(true)
bool(true)
bool(true)