private static void addProduct(int productId, String color, String size, int quantity) { foreach (CartProduct cartProduct in cartProducts) { if (productId == cartProduct.getProductId() && color == cartProduct.getProductColor() && size == cartProduct.getProductSize()) { cartProduct.setQuantity(cartProduct.getQuantity() + quantity); return; } } CartProduct cp = new CartProduct(productId, color, size, quantity); Product p = ProductsManager.getProductById(productId); cp.setProductImages(p.getProductImages()); cp.setProductName(p.getProductName()); cp.setProductPrice(p.getProductPrice()); cartProducts.Add(cp); }