/**  * @param {String} className  * @param {String/Function} superCls  * @param {Function} classImp  */ function $class(className, superCls, classImp){     if(superCls === '') superCls = Object;     function clazz(){         if(typeof this.init == "function"){             this.init.apply(this, arguments);         }     }     var p = clazz.prototype = new superCls();     var _super = superCls.prototype;     window[className] = clazz;     classImp.apply(p, [_super]); }

/**  * 父类 Person  */ $class('Person','',function(){     // 私有属性age     var age;     this.init = function(n, a){         // 公有属性name         this.name = n;         // 私有属性初始化         age = a;     };     this.getName = function(){         return this.name;     };     this.setName = function(name){         this.name = name;     }     this.getAge = function(){         return age;     };     this.setAge = function(a){         age = a;     }; });

$class("Man",Person, function(supr){     var school;     this.init = function(n, a, s){         supr.init.apply(this, [n,a]);         school = s;     }     this.getSchool = function(){         return school;     };     this.setSchool = function(s){         school = s;     }; });

var m = new Man('tom', 25, 'pku'); console.log(m.name); // tom 继承父类的共有属性name可以直接使用点操作符获取 console.log(m.age);  // undefined 父类的私有属性age不能直接使用点操作符获取 console.log(m.getAge()); // 25 可通过父类的共有方法getAge获取私有属性age console.log(m.school); // undefined Man自己的私有属性仍然不能通过点操作符获取 console.log(m.getSchool()); // pku 通过getSchool()方法获取私有属性school