3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a = "var a = {$_SERVER['HTTP_REFERER']};";
Output for 5.5.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Notice: Undefined index: HTTP_REFERER in /in/WQmfG on line 3
Output for 4.3.0 - 5.4.45