function Person(name, age){
  this.name = name;
  this.age = age;
  this.sayHello = function(){
    return "Hello "+ this.name;
  }
}

var person = new Person("dahan",18);
person.sayHello();
//Hello dahan

//类的定义
class Person {
  //ES6中新型构造器
  constructor(name) {
    this.name = name;
  }
  //实例方法
  sayName() {
    console.log("我的名字叫"+ this.name);
  }
}
//类的继承
class Programmer extends Person {
  constructor(name) {
    //直接调用父类构造器进行初始化
    super(name);
  }
  program() {
    cosnole.log("这是我的地盘");
  }
}
//运行测试
var person = new Person('lingxiao');
var coder = new Programmer('coder');

person.sayName();
//我的名字叫lingxiao
coder.sayName();
//我的名字叫coder
coder.program();
//这是我的地盘

class Person {
  constructor(){
    var ob = new Object();
    return Ob;
  }
  sayHello(){
    return "Hello World"
  }
}
var person = new Person();
person.sayHello();
//Uncaught TypeError: person.sayHello is not a function

class Person {
  constructor(name){
    this.name = name;
  }
};
var person = Person("dahan");
//Uncaught TypeError: Class constructor Person4 cannot be invoked without 'new'

class Person{
  constructor(name){
    this.name = name;
  }
  sayHello() {
    return "Hello "+this.name
  }
}
var person = new Person("dahan");
var sayHello = person.sayHello;
sayHello();
//Uncaught TypeError: Cannot read property 'name' of undefined

class Person{
  constructor(name){
    this.name = name;
    this.sayHello = this.sayHello.call(this);
  }
  sayHello() {
    return "Hello "+this.name
  }
}

//类的继承
class Programmer extends Person {
  constructor(name,age) {
    this.age = age;//报错
    //直接调用父类构造器进行初始化
    super(name);
  }
  program() {
    cosnole.log("这是我的地盘");
  }
}