我想根据id覆盖cookie值

Question

在此代码中，我想根据id覆盖cookie值。一旦你将一个值添加到id = 55的cookie中，并且如果我从相同的id添加新值，则使用相同id的新值更新的cookie值不会添加。
这是我的代码

<form method='post'>
<input type="text" hidden="hidden" value="<?php echo $prdctid;?>" name="id">
<input type="number" name="name" value="1" min="1" max="10" />
<input type="submit" id="submit" name="submit" value="Add" />
</form>

if(isset($_POST['submit'])){

    $qtyprid = $_POST['id'];

    $qtyval = $_POST['name'];



    $cart_qty=array();

    $cart_qty[$qtyval]=$qtyprid;

    $cookie = $_COOKIE['qty_items_cookie'];

    $cookie = stripslashes($cookie);

    $saved_cart_qty = json_decode($cookie, true);

    if(!$saved_cart_qty){

        $saved_cart_qty=array(); 

    }

    if(count($saved_cart_qty)>0){

        foreach($saved_cart_qty as $key=>$value){

            $cart_qty[$key]=$value;

        }

    }

    $json = json_encode($cart_qty, true);

    setcookie('qty_items_cookie', $json);
}