JavaScript 创建自定义类型的 7 种模式与 ES6 Class 原理

function createPerson(name, age, job){
  var o = new Object();      // 创建对象
  o.name = name;         // 赋予对象细节
  o.age = age;          // 赋予对象细节
  o.job = job;          // 赋予对象细节
  o.sayName = function(){     // 赋予对象细节
    alert(this.name);
  };
  return o;            // 返回该对象
}
var person1 = createPerson("Nicholas", 29, "Software Engineer");
var person2 = createPerson("Greg", 27, "Doctor");

function Person(name, age, job){
  this.name = name;    // 对象的所有细节全部挂载在 this 对象下面
  this.age = age;
  this.job = job;
  this.sayName = function(){
    alert(this.name);
  };
}
var person1 = new Person("Nicholas", 29, "Software Engineer");
var person2 = new Person("Greg", 27, "Doctor");

function Person(){
}
Person.prototype.name = "Nicholas";
Person.prototype.age = 29;
Person.prototype.job = "Software Engineer";
Person.prototype.sayName = function(){
  alert(this.name);
};
var person1 = new Person();
person1.sayName();   //"Nicholas"
var person2 = new Person();
person2.sayName();   //"Nicholas"
alert(person1.sayName == person2.sayName);   //true

function Person(){
}
Person.prototype = {
  name : "Nicholas",
  age : 29,
  job: "Software Engineer",
  sayName : function () {
    alert(this.name);
  }
};

function Person(){
}
Person.prototype = {
  constructor : Person,
  name : "Nicholas",
  age : 29,
  job: "Software Engineer",
  sayName : function () {
    alert(this.name);
  }
};

function Person(){
}
Person.prototype = {
  name : "Nicholas",
  age : 29,
  job : "Software Engineer",
  sayName : function () {
    alert(this.name);
  }
};
//重设构造函数，只适用于 ECMAScript 5 兼容的浏览器
Object.defineProperty( Person.prototype, "constructor", {
  enumerable: false,
  value: Person
});

function Person(name, age, job){
  this.name = name;
  this.age = age;
  this.job = job;
  this.friends = ["Shelby", "Court"];
}
Person.prototype = {
  sayName : function(){
    alert(this.name);
  }
}
Object.defineProperty( Person.prototype, "constructor", {
  enumerable: false,
  value: Person
);
var person1 = new Person("Nicholas", 29, "Software Engineer");
var person2 = new Person("Greg", 27, "Doctor");
person1.friends.push("Van");
alert(person1.friends);  //"Shelby,Count,Van"
alert(person2.friends);  //"Shelby,Count"
alert(person1.friends === person2.friends);   //false
alert(person1.sayName === person2.sayName);   //true

function Person(name, age, job){
  //属性
  this.name = name;
  this.age = age;
  this.job = job;
  //方法
  if (typeof this.sayAge != "function"){   // 此处应该永远去判断新添加的属性和方法
    Person.prototype.sayName = function(){
      alert(this.name);
    };
    Person.prototype.sayAge = function(){
      alert(this.age);
    };
  }
}
var friend = new Person("Nicholas", 29, "Software Engineer");
friend.sayName();

function Person(name, age, job){
  var o = new Object();
  o.name = name;
  o.age = age;
  o.job = job;
  o.sayName = function(){
    alert(this.name);
  };
  return o;
}
var friend = new Person("Nicholas", 29, "Software Engineer");
friend.sayName();    //"Nicholas"

function Person(name, age, job){
  var o = new Object();    //创建要返回的对象
  //可以在这里定义私有变量和函数
  o.sayName = function(){   //添加方法
    alert(name);
  };
  return o;    //返回对象
}
var friend = Person("Nicholas", 29, "Software Engineer");
friend.sayName(); //"Nicholas"

class Parent {
  name = "qck";
  sex = "male";
  //实例变量
  sayHello(name){
    console.log('qck said Hello!',name);
  }
  constructor(location){
   this.location = location;
  }
}

var _createClass = function () {
  function defineProperties(target, props) {
    for (var i = 0; i < props.length; i++) {
      var descriptor = props[i];
      // 对属性进行数据特性设置
      descriptor.enumerable = descriptor.enumerable || false; // enumerable设置
      descriptor.configurable = true;             // configurable设置
      if ("value" in descriptor) descriptor.writable = true; // 如果有value，那么可写
      Object.defineProperty(target, descriptor.key, descriptor); // 调用defineProperty() 进行属性设置
    }
  }
  return function (Constructor, protoProps, staticProps) {
    // 设置到第一个 Constructor 的 prototype 中
    if (protoProps) defineProperties(Constructor.prototype, protoProps);
    // 设置 Constructor 的 static 类型属性
    if (staticProps) defineProperties(Constructor, staticProps);
    return Constructor;
  };
}();

var Parent = function () {   // 这里是自执行函数
  _createClass(Parent, [{   // Parent的实例方法，通过修改Parent.prototype来完成
    key: "sayHello",
    value: function sayHello(name) {
      console.log('qck say Hello!', name);
    }
  }]);
  function Parent(location) {   //在Parent构造函数中添加实例属性
    _classCallCheck(this, Parent);
    this.name = "qck";
    this.sex = "male";
    this.location = location;
  }
  return Parent;
}();
function _classCallCheck(instance, Constructor) {
  if (!(instance instanceof Constructor)) {
    throw new TypeError("Cannot call a class as a function");
  }
}