run code in 200+ php & hhvm versions
Bugs & Features
<?php $array = array("foo", "bar"); var_dump($array); foreach (&$array as &$value) { if ($value == "foo") unset($value); } var_dump($array); unset($array[1]); var_dump($array);

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)