<?php
//array_walk_recursive a user function recursively to every member of an array

$sweet = array('a' => 'apple', 'b' => 'banana');
$fruits = array('sweet' => $sweet, 'sour' => 'lemon');

function test_print($item, $key)
{
echo "$key holds $item\n";
}

array_walk_recursive($fruits, 'test_print');

//You may notice that the key 'sweet' is never displayed. Any key that holds an array will not be passed to the function.
?>