static void Main(string[] args) { // Create an instance of Interface InterfaceSKU SKU = new SKU(); List <ProductDetails> products = new List <ProductDetails>(); Console.WriteLine("total number of items in the order"); int a = Convert.ToInt32(Console.ReadLine()); while (a > 0) { Console.WriteLine("enter the type of product:A,B,C or D"); string type = Console.ReadLine(); Console.WriteLine("enter the quantity of the product type"); int count = Convert.ToInt32(Console.ReadLine()); ProductDetails product = new ProductDetails(); product.ProductType = type; product.ProductQuantity = count; product.ProductPrice = SKU.GetPriceByType(product); products.Add(product); a = a - count; } int totalPrice = SKU.GetTotal(products); Console.WriteLine(totalPrice); Console.ReadLine(); }