run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = 1; $b =& (true) ? $a : ''; $b = 2; var_dump($a); //$b = (true) ? $b : '';

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)