javascript 创建对象的几种方式

1、通过new Object创建

创建自定义对象的最简单方式就是创建一个Object 的实例，然后再为它添加属性和方法，如下所示。

var person = new Object();
person.name = "Nicholas";
person.age = 29;
person.job = "Software Engineer";
person.sayName = function(){
alert(this.name);
};

2、通过对象字面量创建对象

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

3、通过构造函数模式创建

    function Person(name, age, job){
        this.name = name;
        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");

4、通过原型模式创建

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

5、组合使用构造函数模式和原型模式

  function Person(name, age, job){
        this.name = name;
        this.age = age;
        this.job = job;
        this.friends = ["Shelby", "Court"];
    }
    Person.prototype = {
        constructor : Person,
        sayName : function(){
            alert(this.name);
        }
    }
    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

6、动态原型模式

 function Person(name, age, job){
        //属性
        this.name = name;
        this.age = age;
        this.job = job;
        //方法
        if (typeof this.sayName != "function"){
            Person.prototype.sayName = function(){
                alert(this.name);
            };
        }
    }
    var friend = new Person("Nicholas", 29, "Software Engineer");
    friend.sayName();

7、寄生构造函数模式　　

    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"

8、稳妥构造函数模式

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