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"