array_key_first
PHP 7 >= 7.3.0, PHP 8
array_key_first - Gets the first key of an array
array_key_first(
array$array ): int|string|null
Get the first key of the given array without affecting the internal array pointer.
Parameters
- array
-
An array.
Return Values
Returns the first key of array if the array is not empty; null otherwise.
Notes
There are several ways to provide this functionality for versions prior to PHP 7.3.0. It is possible to use array_keys, but that may be rather inefficient. It is also possible to use reset and key, but that may change the internal array pointer. An efficient solution, which does not change the internal array pointer, written as polyfill:
<?php
if (!function_exists('array_key_first')) {
function array_key_first(array $arr) {
foreach($arr as $key => $unused) {
return $key;
}
return NULL;
}
}
?>