1 // 1) 调用方式
2 new People('whr').sleep(3).eat('apple').sleep(5).eat('durian');
3
4 // 2) 打印结果
5 'hello, whr' -(等待3s)--> 'whr eat apple' -(等待5s)--> 'whr eat durian'
6
7 // 3) 以下是代码实现
8 class People {
9 constructor(name) {
10 this.name = name;
11 this.sayHello();
12 this.queue = Promise.resolve();
13 }
14 sayHello() {
15 console.log(`hello, ${this.name}`);
16 }
17 sleep(time) {
18 this.queue = this.queue.then(() => {
19 return new Promise(res => {
20 setTimeout(() => {
21 res();
22 }, time * 1000)
23 })
24 })
25 return this;
26 }
27 eat(food) {
28 this.queue = this.queue.then(() => {
29 console.log(`${this.name} eat ${food}`);
30 })
31 return this;
32 }
33 }
