快速入门：使用Go语言函数实现简单的电子商务购物车功能

type Product struct {
    ID       int
    Name     string
    Price    float64
    Quantity int
}

type ShoppingCart struct {
    Products []Product
}

func (s *ShoppingCart) AddProduct(p Product) {
    s.Products = append(s.Products, p)
}

func main() {
    cart := &ShoppingCart{}
    
    product := Product{
        ID:       1,
        Name:     "商品1",
        Price:    10.00,
        Quantity: 1,
    }
    
    cart.AddProduct(product)
}

func (s *ShoppingCart) GetProducts() []Product {
    return s.Products
}

func main() {
    cart := &ShoppingCart{}
    
    products := cart.GetProducts()
    
    for _, p := range products {
        fmt.Println(p.Name)
        fmt.Println(p.Price)
    }
}

func (s *ShoppingCart) UpdateQuantity(productID int, quantity int) {
    for i, p := range s.Products {
        if p.ID == productID {
            s.Products[i].Quantity = quantity
        }
    }
}

func main() {
    cart := &ShoppingCart{}
    
    cart.UpdateQuantity(1, 2)
}

func (s *ShoppingCart) RemoveProduct(productID int) {
    for i, p := range s.Products {
        if p.ID == productID {
            s.Products = append(s.Products[:i], s.Products[i+1:]...)
        }
    }
}

func main() {
    cart := &ShoppingCart{}
    
    cart.RemoveProduct(1)
}

func (s *ShoppingCart) Clear() {
    s.Products = nil
}

func main() {
    cart := &ShoppingCart{}
    
    cart.Clear()
}