3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php echo $a ?? 'a';
Output for hhvm-3.11.1 - 3.17.3, 7.0.0 - 7.2.0
a
Output for hhvm-3.10.1
Fatal error: syntax error, unexpected '?' in /in/Qb1p6 on line 3
Process exited with code 255.
Output for 5.5.0 - 5.6.30
Parse error: syntax error, unexpected '?' in /in/Qb1p6 on line 3
Process exited with code 255.