3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $heading = 'h2'; echo ++$heading; system('id');
based on VXLuc
Output for 4.3.0, 5.4.42 - 7.1.7
h3
Output for 4.3.1 - 5.4.41
h3sh: 1: id: not found