JavaScript对象创建的九种方式

1、标准创建对象模式

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

2、字面量模式

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

3、工厂模式

 function createPerson(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 person1 = createPerson("Nicholas", 29, "Software Engineer");
 var person2 = createPerson("Greg", 27, "Doctor");

4、构造函数模式

 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");

5、原型模式

 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

6、组合构造函数和原型模式

 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

7、动态原型模式（这里只在 sayName()方法不存在的情况下，才会将它添加到原型中。）

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

8、寄生构造函数模式（除了使用 new 操作符并把使用的包装函数叫做构造函数之外，这个模式跟工厂模式其实是一模一样的。）

 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"

9、稳妥构造函数模式（一是新创建对象的实例方法不引用 this；二是不使用 new 操作符调用构造函数）

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