1.最简单的创建对象方法
var person = new Object();
person.name = "sam wu";
person.age = 25;
person.job = "frontend engineer";
person.sayName = function(){
alert(this.name);
}; person.sayName();
2.工厂模式创建对象
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("sam", 29, "frontend Engineer");
var person2 = createPerson("rendy", 27, "Python");
person1.sayName(); //"sam"
person2.sayName(); //"rendy"
3.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("sam", 29, "frontend Engineer");
var person2 = new Person("rendy", 27, "Python");
person1.sayName(); //"sam"
person2.sayName(); //"rendy"
alert(person1 instanceof Object); //true
alert(person1 instanceof Person); //true
alert(person2 instanceof Object); //true
alert(person2 instanceof Person); //true
alert(person1.constructor == Person); //true
alert(person2.constructor == Person); //true
alert(person1.sayName == person2.sayName); //false
4.原型模式
可以让多个实例，共享属性和方法。
function Person(){
}
Person.prototype.name = "sam";
Person.prototype.age = 25;
Person.prototype.job = "Software Engineer";
Person.prototype.sayName = function(){
alert(this.name);
};
var person1 = new Person();
person1.sayName(); //"sam"
var person2 = new Person();
person2.sayName(); //"sam"
alert(person1.sayName == person2.sayName); //true
alert(Person.prototype.isPrototypeOf(person1)); //true
alert(Person.prototype.isPrototypeOf(person2)); //true
//only works if Object.getPrototypeOf() is available.ECMA5支持
if (Object.getPrototypeOf){
alert(Object.getPrototypeOf(person1) == Person.prototype); //true
alert(Object.getPrototypeOf(person1).name); //"sam"
}
4.1 实例对象属性和原型属性的优先级
function Person(){
}
Person.prototype.name = "sam";
Person.prototype.age = 29;
Person.prototype.job = "Software Engineer";
Person.prototype.sayName = function(){
alert(this.name);
};
var person1 = new Person();
var person2 = new Person();
person1.name = "Rendy";
alert(person1.name); //"Rendy" – from instance 来自对象
alert(person2.name); //"sam" – from prototype 来自原型属性
4.2 同名，只是屏蔽，非覆盖
function Person(){
}
Person.prototype.name = "sam";
Person.prototype.age = 29;
Person.prototype.job = "Software Engineer";
Person.prototype.sayName = function(){
alert(this.name);
};
var person1 = new Person();
var person2 = new Person();
person1.name = "rendy";
alert(person1.name); //"rendy" – from instance
alert(person2.name); //"sam" – from prototype
delete person1.name;
alert(person1.name); //"sam" - from the prototype
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("sam", 29, "Frontend Engineer");
var person2 = new Person("rendy", 27, "Python");
person1.friends.push("christ");
alert(person1.friends); //"Shelby,Court,christ"
alert(person2.friends); //"Shelby,Court"
alert(person1.friends === person2.friends); //false
alert(person1.sayName === person2.sayName); //true
6.寄生构造函数函数模式
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;
}
// 这里用了new关键字，但是Person函数的内容是返回一个对象。这样就不会生成一个新的实例。而是跟工厂模式效果一样。
var friend = new Person("sam", 25, "Front Engineer");
friend.sayName(); //"sam"
以上内容来自《JavaScript高级程序设计第三版》