array_walk_recursive() Function in PHP 8.2, PHP 8.3 & PHP 8.4
The `array_walk_recursive()` function in PHP applies a user-defined function to every element of a multidimensional array. It works recursively, meaning it will process nested arrays as well.
Syntax:-
array_walk_recursive(array &$array, callable $callback, mixed $userdata = null): bool
`$array`: The input array (passed by reference).
`$callback`: A user-defined function to apply to each element.
`$userdata` (optional): Additional data to pass to the callback function.
Example:-
<?php
function modifyValues(&$value, $key, $prefix) {
$value = $prefix . $value;
}
$arr = [
"name" => "John",
"details" => [
"age" => 30,
"city" => "New York"
]
];
array_walk_recursive($arr, "modifyValues", "PHP-");
print_r($arr);
?>
Output:
Array ( [name] => PHP-John [details] => Array ( [age] => PHP-30 [city] => PHP-New York ) )