Online PHP editor | refs for A68VA

<?php $arr = array ( 0 => array ( 0 => array ( 'userid' => '1610', ), 1 => array ( 'userid' => '1614', ), 2 => array ( 'userid' => '1616', ), ), 1 => array ( 0 => array ( 'userid' => '1610', ), 1 => array ( 'userid' => '1614', ), 2 => array ( 'userid' => '1616', ), 3 => array ( 'userid' => '1618', ), ), ); foreach($arr as $sub){ $res[][key($sub[0]) . "s"] = array_column($sub, 'userid'); } var_dump($res);