- array_walk: documentation ( source)
<?php
$array = array(1,2,3,4,5,6,7,8,9);
function soma_1($chave, $valor){
$array[$chave][$valor] = $valor + 1;
}
function echo_array($chave, $valor){
echo "$chave \n";
}
array_walk($array,'soma_1');
array_walk($array,'echo_array');