3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $foo = function () { return $foo;}; var_dump($foo());
based on tOXSi
Output for 5.6.0 - 5.6.30, hhvm-3.18.5 - 3.21.3, 7.0.0 - 7.3.0rc2
Notice: Undefined variable: foo in /in/nilA0 on line 3 NULL
Output for hhvm-3.22.0
Notice: Undefined variable: foo in /in/nilA0 on line -1 NULL