3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $i = 0; $a = array(); $a[$i] = ++$i + $i++; var_dump($a);
Output for 5.1.0 - 7.1.0
array(1) { [2]=> int(2) }
Output for 4.3.0 - 5.0.5
array(1) { [0]=> int(2) }