3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a='bill'; $$a = 'food'; $$$a='bar'; echo $foo;
Output for 5.0.4 - 5.6.28, hhvm-3.12.0, 7.0.0 - 7.1.0
Notice: Undefined variable: foo in /in/XVvS0 on line 6
Output for hhvm-3.10.0

Process exited with code 153.
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: foo in /in/XVvS0 on line 6