package strategy import "fmt" type Payment struct { context *PaymentContext strategy PaymentStrategy } type PaymentContext struct { Name, CardID string Money int } func NewPayment(name, cardid string, money int, strategy PaymentStrategy) *Payment { return &Payment{ context: &PaymentContext{ Name: name, CardID: cardid, Money: money, }, strategy: strategy, } } func (p *Payment) Pay() { p.strategy.Pay(p.context) } type PaymentStrategy interface { Pay(*PaymentContext) } type Cash struct{} func (*Cash) Pay(ctx *PaymentContext) { fmt.Printf("Pay $%d to %s by cash", ctx.Money, ctx.Name) } type Bank struct{} func (*Bank) Pay(ctx *PaymentContext) { fmt.Printf("Pay $%d to %s by bank account %s", ctx.Money, ctx.Name, ctx.CardID) }