JavaScript面向对象三大特性案例

1.封装性

/**
 -  利用函数创建的作用域达到数据封装的目的。
 - @type {{getName, setName}}
  */
 
  var obj=(function () {
var _name="gcy";
return {
    getName:function () {
        return _name;
    },
    setName:function (val) {
        _name=val;
    }
 
};
 })();
 obj._name;  //undefined
 obj.getName(); //gcy

2.继承性

/**
 * 简单的es5原型继承
 * @constructor
 */
var A=function () {
}
A.prototype={name:"gcy"};
 
var B=function () {
};
B.prototype=new A();
 
var b=new B();
console.log(b.name);
/**
 * e6继承实现demo
 */
class People{
    constructor(name){
        this.name=name;
    }
    getName(){
        return www.90168.org 
this.name;
    }
}
 
class Black extends People{
    constructor(name){
        super(name);
    }
    speak(){
        return " i am black";
    }
}
var peo=new Black("gcy");
 
console.log(peo.getName()+' says '+peo.speak());

3.多态性

 /**
     * 多态的实现案例
     * @param animal
     */
    var makeSound=function (animal) {
        animal.sound();
    }
    var Cat=function () {
    }
    var Dog=function () {
    }
    Cat.prototype.sound=function () {
        console.log("喵喵喵")
    }
    Dog.prototype.sound=function () {
        console.log("旺旺旺")
    }
    makeSound(new Cat());
    makeSound(new Dog());