JavaScript對象創建的九種方式

1、標准創建對象模式

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、工廠模式

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、構造函數模式

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、組合構造函數和原型模式

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、動態原型模式（這里只在 sayName()方法不存在的情況下，才會將它添加到原型中。）

function Person(name, age, job){
    this.name = name;
    this.age = age;
    this.job = job;
    if (typeof this.sayName != "function"){  6         Person.prototype.sayName = function(){alert(this.name);};  7  }  8 }
var friend = new Person("Nicholas", 29, "Software Engineer");
friend.sayName(); 

 

8、寄生構造函數模式（除了使用 new 操作符並把使用的包裝函數叫做構造函數之外，這個模式跟工廠模式其實是一模一樣的。）

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、穩妥構造函數模式（一是新創建對象的實例方法不引用 this；二是不使用 new 操作符調用構造函數）

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"