3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $x = 0; $a = array(&$x); $c =& $a; $b = $a; $x = 2; unset($x); $b[0]++; $b[0]++; echo $a[0], ' ', $b[0];
based on 1h6fJ
Output for 7.0.0 - 7.1.0
2 4
Output for 4.3.0 - 5.6.28
4 4