Framwork/Assets/Scripts/Runtime/UI/Data/ShoppingCart.cs

using System.Collections.Generic;

namespace Runtime.UI.Data
{
    public class ShoppingCart
    {
        public string userName = string.Empty;
        public string userModie = string.Empty;
        public string userEmail = string.Empty;
        public List<ShoppingCartData> datas = new List<ShoppingCartData>();
        public string totalQuantity = "0";
        public string itemsSubTotal = "0";
        public string discount = "0";
        public string totalAmount = "0";

        public void AddData(ShoppingCartData data)
        {
            datas.Add(data);
            UpdateDatas();
        }

        public void UpdateDatas()
        {
            totalQuantity = datas.Count.ToString();
            itemsSubTotal = string.Empty;
            discount = string.Empty;
            totalAmount = string.Empty;

            int i = 0, d = 0, t = 0;
            foreach (var shoppingCartData in datas)
            {
                i += shoppingCartData.bookAmount * shoppingCartData.count;
                d += shoppingCartData.bookDiscount * shoppingCartData.count;
                t += shoppingCartData.bookAmount * shoppingCartData.count;
            }

            itemsSubTotal = i.ToString();
            discount = d.ToString();
            totalAmount = t.ToString();
        }
    }

    public class ShoppingCartData
    {
        public string bookName;
        public int bookAmount;
        public int bookDiscount;
        public int count;
        public byte[] previewImage;
        public byte[] tifImage;
    }
}