HomeMenu
Jesus · Bible · HTML · CSS · JS · PHP · SVG · Applications

array_key_exists

Description

The array_key_exists of Array for PHP checks if the given key or index exists in the array.

Syntax

array_key_exists(
    string|int|float|bool|resource|null $key,
    array $array
): bool

Parameters

key

Value to check.

array

An array with keys to check.

Return

Returns true on success or false on failure.

Examples

1 · key · null · array

<?

$key = null;
$array =
[
    null => 0,
    null => 1
];

$return = array_key_exists($key, $array);

var_export($return);

true

2 · key · bool · array

<?

$key = false;
$array =
[
    false => 0,
    true => 1
];

$return = array_key_exists($key, $array);

var_export($return);

true

3 · key · int · array

<?

$key = 0;
$array =
[
    0,
    1
];

$return = array_key_exists($key, $array);

var_export($return);

true

4 · key · float · array

<?

$key = 0.1;
$array =
[
    0.1 => 0,
    0.2 => 1
];

$return = array_key_exists($key, $array);

var_export($return);

true

5 · key · string · array

<?

$key = "a";
$array =
[
    "a" => 0,
    "b" => 1
];

$return = array_key_exists($key, $array);

var_export($return);

true

6 · key · resource · array

<?

$filename = $_SERVER["DOCUMENT_ROOT"] . "/assets/txt/1.txt";
$mode = "r";

$resource = fopen($filename, $mode);

$key = get_resource_type($resource);
$array =
[
    "stream" => 0,
    "stream" => 1
];

$return = array_key_exists($key, $array);

var_export($return);

true