3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php error_reporting(-1); function foo (&$x) { $x = 2; } foo($xizzy); echo $xizzy;
based on HDDP0
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
2