array_key_exists
PHP function
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(PHP 4 >= 4.0.7, PHP 5, PHP 7, PHP 8)
Checks if the given key or index exists in the array
Description
array_key_exists(string|int|float|bool|resource|null $key, array $array): bool
array_key_exists() returns true if the given key is set in the array. key can be any value possible for an array index.
Parameters
keyValue to check.
arrayAn array with keys to check.
Return Values
Success
Note
array_key_exists() will search for the keys in the first dimension only. Nested keys in multidimensional arrays will not be found.
Changelog
| Version | Description |
|---|---|
| 8.5.0 | Using null in the key parameter is deprecated, use an empty string instead. |
| 8.0.0 | The key parameter now accepts bool, float, int, null, resource, and string as arguments. |
| 8.0.0 | Passing an object to the array parameter is no longer supported. |
| 7.4.0 | Passing an object to the array parameter has been deprecated. Use property_exists() instead. |
Examples
array_key_exists() example
php
<?php
$searchArray = ['first' => 1, 'second' => 4];
var_dump(array_key_exists('first', $searchArray));
?>The above example will output:
output
bool(true)isset() does not return true for array keys that correspond to a null value, while array_key_exists() does.
php
<?php
$searchArray = ['first' => null, 'second' => 4];
var_dump(isset($searchArray['first']));
var_dump(array_key_exists('first', $searchArray));
?>The above example will output:
output
bool(false)
bool(true)