3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $foo = 0; $bar = function() use (&$foo) { return ++ $foo; }; var_dump($bar() ?? $bar() ?? $bar(), $foo );
based on kspD4
Output for 7.0.0 - 7.2.0
int(1) int(1)
Output for 5.3.20 - 5.6.21
Parse error: syntax error, unexpected '?' in /in/4qLPu on line 4
Process exited with code 255.