3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $x = 0; $a = array(&$x); $b = $a; $x = 2; unset($x); echo $a[0], ' ', $b[0];
based on qNiGW
Output for 4.3.0 - 5.6.21, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
2 2