3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = 'x'; $a++; echo $a;
Output for 4.3.0 - 5.6.30, hhvm-3.11.1 - 3.17.3, 7.0.0 - 7.1.7
y
Output for hhvm-3.10.1

Process exited with code 137.