Online PHP editor | refs for Doo0R

<?php $yourarray = [ 'ABC123-A', 'BG231-B', 'ABC123-A', 'BG231-E', 'BG231-F', 'BG231-G', 'BG231-H', 'ABC123-A', 'BG231-J', 'BG231-K', 'ABC123-A' ]; $duplicated=null; foreach($yourarray as $k => $v){ foreach($yourarray as $k2 => $v2){ if($v == $v2 && $k2 != $k){ $duplicated[$k]=$v; break; } } } var_export($duplicated);