3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php echo abs(x);
based on UmtYc
Output for 7.2.0
Warning: Use of undefined constant x - assumed 'x' (this will throw an Error in a future version of PHP) in /in/r21EJ on line 3 0
Output for 5.3.20 - 7.1.10
Notice: Use of undefined constant x - assumed 'x' in /in/r21EJ on line 3 0