3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = null; $x = $a ?? "butts"; echo $x;
Output for hhvm-3.15.4, 7.0.0 - 7.3.0rc3
butts
Output for 5.6.0 - 5.6.30
Parse error: syntax error, unexpected '?' in /in/AO4TA on line 5
Process exited with code 255.