Как соединить массивы? (БЕЗ НУМЕРАЦИИ)

Помогите: Возврощаяет

Array
(
[id] => 5
[count] => 1
)
Array
(
[id] => 10
[count] => 1
)
Array
(
[id] => 3
[count] => 1
)
Array
(
[id] => 8
[count] => 1
)

Нужно:

[0](
[id] => 5
[count] => 1
)
[1](
[id] => 10
[count] => 1
)
[2](
[id] => 3
[count] => 1
)
[3](
[id] => 8
[count] => 1
)

Мой код:

foreach ($in_cart as $key => $val) {
          $new_array = [];
          $new_array['id'] = $val['id'];
          $new_array['count'] = $val['count'];
          if($val['id'] == $id){
              $new_array['count'] = $new_array[$key]['count'] + 1;
          }
          print_r($new_array);
      }

Вот что содержит $in_card:

Array
(
[0] => Array
    (
        [id] => 5
        [count] => 1
    )

[1] => Array
    (
        [id] => 10
        [count] => 1
    )

[2] => Array
    (
        [id] => 3
        [count] => 1
    )

[3] => Array
    (
        [id] => 8
        [count] => 1
    )

И ОБЯЗАТЕЛЬНО чтобы count + 1