JS中的phototypeJS中的phototype

People.sleep = function(){console.log('I Am Sleeping ...')}
People.sleep()

People.prototype.constructor.sleep
ƒ (){console.log('I Am Sleeping ...')}

People.prototype.constructor.sleep()
I Am Sleeping ...

var p = new People('Jack')

p.__proto__.constructor.sleep()

I Am Sleeping ...

function People(name){
    this.name = name;
    this.hello = function(){
        console.log('Hello,World')
    }} 

var p = new People('Jack')

p: People {name: "Jack", hello: ƒ}

p.hello
ƒ (){
        console.log('Hello,World')
    }

typeof p.hello   =  "function"

p.hello()  输出  Hello,World
p.name 输出  "Jack"

p.__proto__

p.__proto__
{constructor: ƒ}

p.__proto__.constructor

ƒ People(name){
    this.name = name;
    this.hello = function(){
        console.log('Hello,World')
    }}

function employee(name,job,born){
  this.name=name;
  this.job=job;
  this.born=born;
}
var bill=new employee("Bill Gates","Engineer",1985);
employee.prototype.salary=null;
bill.salary=20000;
console.log(bill.salary);