text: function Person(name,sex,age,address){
      this.name= name,
      this.sex = sex,
      this.age =age,
      this.address = address,
      this.sayName=function(){
          console.log(this.name)
      }
  }
  
  Person.prototype.sayName2 = function(){
      console.log("this is say name 2")
  }
  
  
  var p1 = new Person("张三",'男',20,"南昌市")
  console.log(p1);
  console.log(p1.__proto__);
  p1.sayName()
  p1.sayName2()