run code in 200+ php & hhvm versions
Bugs & Features
<?php function event($n, $h = null) { static $e = []; return $h ? $e[$n][] = $h : (isset($e[$n]) ? array_walk($e[$n], function($e) {$e();}) : 0); } event('hello', function () { echo 'hello!'; }); echo event('hello') ? 'true!' : 'false!'; echo event('world') ? 'true!' : 'false!';
based on AVjXY

Here you find the average performance (time & memory) of each version. A grayed out version indicates it didn't complete successfully (based on exit-code).
Note: hhvm uses a JIT which only kicks in after a few runs. Since we run scripts only once, hhvm always runs slower.

VersionSystem time (s)User time (s)Memory (MiB)