3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = 10; $a ^= $b; echo $a;
Output for 5.6.0 - 5.6.30, hhvm-3.15.4, 7.0.0 - 7.3.0rc3
Notice: Undefined variable: b in /in/X47Op on line 4 10