array_ampersand.php

<?php
$a = array(1,2,3);
$b = array(4,5,6);
foreach (array($a, &$b) as &$c) {
    foreach ($c as &$d) {
        $d *= 100;
    }
}
print_r($a);
print_r($b);
//Array
//(
//    [0] => 1
//    [1] => 2
//    [2] => 3
//)
//Array
//(
//    [0] => 400
//    [1] => 500
//    [2] => 600
//)