public static void AddNewProducts(Store store, Product product) { Console.WriteLine("Enter product id:"); int product_id = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter product name:"); string product_name = Console.ReadLine(); Console.WriteLine("Enter product price:"); int product_price = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter product category:"); string product_category = Console.ReadLine(); Console.WriteLine("Enter brand name:"); string brand_name = Console.ReadLine(); Product p = new Product(product_id, product_name, product_price, product_category); int check = p.AddNewProduct(brand_name, store); if (check == 1) { Console.WriteLine("Product is added successfully"); } else if (check == -1) { Console.WriteLine("This brand does not exist !!!"); } if (check == 0) { Console.WriteLine("Product id already exists !!!"); } }