Let's continue with Xiaoming's example
Last time, when it came to Xiaoming's buying back everything, the college gentleman looked at the bill: ￥ 4386
Although I think the money costs a little more, I still need to give Xiao Ming to do the purchase this time
I'll give you a bill, Xiao Ming. You have to write down the bill for every item you buy and ask the boss to sign it
class Order {
constructor() {
this.goodList = [];
this.total = 0;
}
add(good) {
this.goodList.push(good);
this.total += good.price;
}
}
Order.getOrder = (function() { //Using closures ensures that an order object is maintained
let order;
return function() {
if(!order) {
order = new Order();
}
return order;
}
})();
class Good {
constructor(name, price) {
this.name = name;
this.price = price;
}
showInfo() {
console.log(`Trade name: ${this.name} Price:￥${this.price}`);
}
}
class Shop {
constructor() {
this.order = Order.getOrder();
}
sell(good) {
this.order.add(good);
}
}
class ToyShop extends Shop{
constructor() {
super();
}
sell(name) {
switch(name) {
case 'Lego': super.sell(new Good('Lego', 3600));
case 'Building blocks': super.sell(new Good('Building blocks', 288));
}
}
}
class SportShop extends Shop{
constructor() {
super();
}
sell(name) {
switch(name) {
case 'Football': super.sell(new Good('Football', 80));
case 'Basketball': super.sell(new Good('Basketball', 65));
}
}
}
class Student {
constructor(name) {
this.name = name;
this.order = Order.getOrder();
}
getTotal() {
console.log(`Total purchase price:￥${this.order.total}`);
}
}
Xiaoming is walking on the street
let xiaoming = new Student('Xiao Ming');
Xiaoming goes into the football shop and buys football and basketball
let sportShop = new SportShop();
sportShop.sell('Football');
sportShop.sell('Basketball');
Xiaoming enters the stationery store and buys Lego and building blocks
let toyShop = new ToyShop();
toyShop.sell('Lego');
toyShop.sell('Building blocks');
Xiaoming finished purchasing
xiaoming.getTotal();
Mr. Zhang gets the bill and has a look: Oh, how expensive is LEGO? Next time, I won't buy LEGO