//装饰者模式：就是在保证不改变原有对象的基础上，去扩展一些想要的方法或去求var CarInterface = new BH.Interface('CarInterface' , ['getPrice' , 'assemble']);var Car = function(car){ //也可以这样写类。//让子类都有这个属性this.car = car ; //检查接口BH.Interface.ensureImplements(this , CarInterface);};Car.prototype = {constructor :Car,getPrice:function(){return 200000 ; },assemble:function(){document.write('组装汽车...');}};var LightDecorator = function(o){ //函数调用的时候执行//继承属性并传值，this.car = car，此时传进来的car是上面的Car对象。LightDecorator.superClass.constructor.call(this , o);/*相当于复制代码：this.car = car ; BH.Interface.ensureImplements(this , CarInterface);*/};BH.extend(LightDecorator , Car);  //立即执行LightDecorator.prototype = {constructor:LightDecorator , getPrice:function(){return  this.car.getPrice() + 10000; },assemble:function(){document.write('组装车灯...');}                    };var IceBoxDecorator = function(o){//继承属性并传值，this.car = car，此时传进来的car是上面的LightDecorator对象。js没有多态概念，IceBoxDecorator.superClass.constructor.call(this , o);                    };BH.extend(IceBoxDecorator , Car);  //原型继承 IceBoxDecorator.prototype = {constructor:IceBoxDecorator , getPrice:function(){return  this.car.getPrice() + 20000; },assemble:function(){document.write('组装车载冰箱...');}                    };                var car  = new Car();alert(car.getPrice());car.assemble();var L = new LightDecorator(car);alert(L.getPrice());L.assemble();        var I = new IceBoxDecorator(L);alert(I.getPrice());I.assemble();        

//装饰者 不仅可以用在类上， 还可以用在函数上//返回一个当前时间的字符串表示形式function getDate(){return (new Date()).toString();};// 包装函数 (装饰者函数)function upperCaseDecorator(fn){return function(){return fn.apply(this, arguments).toUpperCase();}};alert(getDate());var getDecoratorDate = upperCaseDecorator(getDate);alert(getDecoratorDate());