PHP group by key value in multi array

PHP group by key value in multi array

        $arr = [
            [
                'itemId' => 1,
                'itemDescription' => 'ItemDescription',
                'product' => 'productA',
                'productDescription' => 'ProdADesc'
            ],
            [
                'itemId' => 1,
                'itemDescription' => 'ItemDescription',
                'product' => 'productB',
                'productDescription' => 'ProdBDesc'
            ],
            [
                'itemId' => 1,
                'itemDescription' => 'ItemDescription',
                'product' => 'productC',
                'productDescription' => 'ProdCDesc'

            ],
        ];

        foreach ($arr as $key => $val){
            $resultKey = array_search($val['itemId'], array_column($result, 'itemId'));
            if($resultKey === false){
                $result[$key]['itemId'] = $val['itemId'];
                $result[$key]['itemDescription'] = $val['itemDescription'];
                $result[$key]['products'][] = [
                    'product' => $val['product'],
                    'productDescription' => $val['productDescription']
                ];
            }else{
                $result[$resultKey]['products'][] = [
                    'product' => $val['product'],
                    'productDescription' => $val['productDescription']
                ];
            }
        }

/*********** Result array **********************

/var/www/zug/src/ApiBundle/Controller/ConversationsController.php:79:
array (size=1)
  0 => 
    array (size=3)
      'itemId' => int 1
      'itemDescription' => string 'ItemDescription' (length=15)
      'products' => 
        array (size=3)
          0 => 
            array (size=2)
              'product' => string 'productA' (length=8)
              'productDescription' => string 'ProdADesc' (length=9)
          1 => 
            array (size=2)
              'product' => string 'productB' (length=8)
              'productDescription' => string 'ProdBDesc' (length=9)
          2 => 
            array (size=2)
              'product' => string 'productC' (length=8)
              'productDescription' => string 'ProdCDesc' (length=9)

*/