//普通用户
function Price(){
this.discount = 1
}
Price.prototype.getPrice = function(price){
return price * this.discount
}
//vip用户
function VipPrice(){
this.discount = 0.5
}
VipPrice.prototype.getPrice = function(price){
return price * this.discount
}
//超级VIP用户
function SuperVipPrice(){
this.discount = 0.3
}
SuperVipPrice.prototype.getPrice = function(price){
return price * this.discount
}
//上下文
function Context(){
this.name=""
this.strategy=null
this.price=0
}
Context.prototype.set=function(name,strategy,price){
this.name=name
this.strategy=strategy
this.price=price
}
Context.prototype.getResult=function(){
console.log(this.name+"的价格是:"+this.strategy.getPrice(this.price))
}
let context = new Context()
let price = new Price()
context.set("普通用户",price,200)
context.getResult()
let vipPrice = new VipPrice()
context.set("vip用户",vipPrice,200)
context.getResult()
let superVipPrice = new SuperVipPrice()
context.set("超级vip用户",superVipPrice,200)
context.getResult()