实现一个LazyMan，可以按照以下方式调用:
LazyMan(“Hank”)输出:
Hi! This is Hank!
LazyMan(“Hank”).sleep(10).eat(“dinner”)输出
Hi! This is Hank!
//等待10秒..
Wake up after 10
Eat dinner~
LazyMan(“Hank”).eat(“dinner”).eat(“supper”)输出
Hi This is Hank!
Eat dinner~
Eat supper~
LazyMan(“Hank”).sleepFirst(5).eat(“supper”)输出
//等待5秒
Wake up after 5
Hi This is Hank!
Eat supper
以此类推。
题目解析：看起来是链式调用并且有流程控制其中sleepFisrt要在所有函数之前执行。大致的思路是创建一个任务队列，将每一项任务（输出名字、吃饭、睡觉）都放进队列里按顺序执行。代码如下：
function LazyMan(name){
let _lazyMan = {
sayHi : function () {
queue.push(() => {
console.log('Hi! This is'+name)
this.next();
})
},
eat : function (food) {
queue.push(() => {
console.log('Eat '+food)
this.next();
})
return this;
},
sleep : function (second) {
queue.push(() => {
setTimeout(() => {
console.log("wake up after "+ second + "秒")
this.next();
},second * 1000)
})
return this;
},
sleepFirst : function (second) {
queue.unshift(() => {
setTimeout(() => {
console.log("wake up after "+ second + "秒")
this.next();
},second * 1000)
})
return this;
},
next : function () {//函数依次执行
let fn = queue.shift();
fn && fn();
}
}
let queue = [];//存放函数的任务队列
_lazyMan.sayHi();//将打招呼放进队列
setTimeout(function () {//开始执行任务队列的里的函数
_lazyMan.next();
})
return _lazyMan;
}
// LazyMan("kakao")
// LazyMan("kakao").eat("apple").eat("banana")
// LazyMan("kakao").sleep(3).eat("apple")
// LazyMan("kakao").sleepFirst(3).eat("apple")
