Online PHP editor | refs for C5642

<?php $array = [ ['brand' => 'ABC', 'model' => 'xyz', 'size' => 13], ['brand' => 'QWE', 'model' => 'poi', 'size' => 23], ['brand' => 'ABC', 'model' => 'xyz', 'size' => 18] ]; var_export( array_values( array_reduce( $array, function ($carry, $row) { $compositeKey = $row['brand'] . '_' . $row['model']; if (!isset($carry[$compositeKey])) { $carry[$compositeKey] = $row; } else { $carry[$compositeKey]['size'] = array_merge( (array)$carry[$compositeKey]['size'], [$row['size']] ); } return $carry; } ) ) );