3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a=array('a'=>array(1,2,3), 'b'=>array(4,5,6), 'c'=>array(7,8,9)); $_a=&$a['a']; $_a['x']='aaaaaaa'; print_r($a); $_a=&$a['b']; $_a['x']='bbbbbb'; print_r($a);

preferences:
221.84 ms | 402 KiB | 5 Q