It is a process control, just like lazyMan, you can see this http://www.cnblogs.com/Upton/...

I guess what you want is this. Here is a principle. The code structure is very simple

When there is an execution queuejobs调用before的时候把内容加到队列头部 调用getup, add the content to the end

The basic principle is to use the functions insetTimeout时间设置为0setTimeoutto be executed after everything in the current operating environment has been run

So I’m wondering if the third line of the question’s third example is output again嘘嘘Is it a typo

But even if it’s not a clerical error, it’s okay. According to this principle, you can change it however you want. It’s not a problem to call it multiple times

function person(name){ var self = {}; self.jobs = ["hi " + name]; self.before = function(s){ self.jobs.unshift(name + " " + s); return this; } self.getup = function (s){ self.jobs.push("getup and " + s); return this; } setTimeout(function(){console.log(self.jobs)}, 0) return self; }

function person(name){ setTimeout(() => console.log(`hi ${name}`)); this.name = name; this.before = before_todo => { this.before_todo = before_todo; console.log(`${this.name} ${before_todo}`); return this; } this.getup = getup_todo => { setTimeout(() => { var str = this.name; if (this.before_todo) str += ' ' + this.before_todo; str += (' getup and ' + getup_todo); console.log(str); }); return this; } return this; }

Refer to the promise implementation process