Online PHP editor | refs for MY6Xu

<?php $data = [ [ 'id' => 1331, 'label' => 'PMI', 'cost' => 98.25, 'cid' => 22, 'product_id' => 133, ], [ 'id' => 1341, 'label' => 'PMI', 'cost' => 98.25, 'cid' => 22, 'product_id' => 134, ], ]; $output = []; foreach ($data as $item) { if (!isset($output[$item['cid']])) { $output[$item['cid']] = [ 'label' => $item['label'], 'cost' => 0, 'cid' => $item['cid'], ]; } $output[$item['cid']]['cost'] += $item['cost']; } print_r($output);