- var_dump: documentation ( source)
<?php
$arr = array(1);
$a =& $arr[0]; //$a and $arr[0] are in the same reference set
$arr2 = $arr; //not an assignment-by-reference!
var_dump($arr2);
$arr2[0]++;
var_dump($arr2);
var_dmp($a);
$arr[0]++;
var_dump($arr2);
var_dump($arr);
var_dmp($a);