3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $first = Array(607,608,609,610); $second = Array(608,607,609); $arr = array_merge($first, $second); var_dump(array_diff($arr, array_diff_assoc($arr, array_unique($arr))));
based on Z1vpe
Output for 5.6.0 - 5.6.30, hhvm-3.15.4, 7.0.0 - 7.2.6
array(1) { [3]=> int(610) }