3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump( $a ?? $b );
Output for 7.0.0 - 7.2.0
Notice: Undefined variable: b in /in/m0YnP on line 4 NULL
Output for 5.3.20 - 5.6.21
Parse error: syntax error, unexpected '?' in /in/m0YnP on line 4
Process exited with code 255.