javascript prototype 实现类似OOP继承

这里要说明的是，公有属性（使用this.修饰符）可以被覆盖，私有属性(使用var 修饰符)不能被覆盖

子类不能访问父类的私有属性，父类的方法正常访问父类的私有变量。

function Vegetable(){ this.taste='delicious'; var a = 'I\'m Vegetable\'a!' this.fun1 = function(){ alert('Vegetable fun1 doing...'); } this.fun3 = function(){ alert(a); } } function Celery(){ var a = 'I\'m Celery\' a'; this.color = 'green'; this.taste = 'bad'; this.fun1a = function(){ alert('Celeryfun1 doing...'); } this.fun2 = function(){ alert('Celery fun2 doing...'); } this.fun4 = function(){ alert(a); } } Celery.prototype = new Vegetable(); var stick = new Celery(); var polymorphed = stick.taste; //alert(polymorphed); //alert(stick.color); //stick.fun1(); //stick.fun2(); //stick.fun3(); stick.fun4();