- var_dump: documentation ( source)
- array_walk_recursive: documentation ( source)
<?php
$a = ['a', ['b', ['c']]];
function cb($i){ $i = 'z'; }
function cb2(&$i) { $i = 'z'; }
array_walk_recursive($a, 'cb' );
var_dump($a);
array_walk_recursive($a, 'cb2' );
var_dump($a);