(function(){    function _$(els){        //...    }    _$.prototype={        each:function(fn){            for(var i=0,len=this.elements.length;i<len;++i){                fn.call(this,this.elements[i]);            }            return this;        },        setStyle:function(prop,val){            this.each(function(el){                el.style[prop]=val;            });            return this;        },        show:function(){            var that=this;            this.each(function(el){                that.setStyle(‘display‘,‘block‘);            });            return this;        },        addEvent:function(type,fn){            var add=function(el){                if(window.addEventListener){                    el.addEventListener(type,fn,false);                }                else if(window.attachEvent){                    el.attachEvent(‘on‘+type,fn);                }            };            this.each(function(el){                add(el);            });            return this;        }    };    window.$=function(){        return new _$(arguments);    };})();

window.API=window.API||function(){    var name=‘Hello World‘;    this.setName=function(newName){        name=newName;        return this;    };    this.getName=function(callback){        callback.call(this,name);        return this;    };};var o2=new API;o2.getName(console.log).setName(‘Meow‘).getName(console.log);

var BicycleShop=function(){};BicycleShop.prototype={    sellBicycle:function(model){        var bicycle;        switch(model){            case‘The Speedster‘:            bicycle=new Speedster();            break;            case‘The Lowrider‘:            bicycle=new Lowrider();            break;            case‘The Comfort Cruiser‘:            default:            bicycle=new ComfortCruiser();        }        interface.ensureImplements(bicycle,Bicycle);        bicycle.assemble();        bicycle.wash();        return bicycle;    }};

var BicycleFactory={    createBicycle:function(model){        var bicycle;        switch(model){            case‘The Speedster‘:            bicycle=new Speedster();            break;            case‘The Lowrider‘:            bicycle=new Lowrider();            break;            case‘The Flatlander‘:            bicycle=new Flatlander();            break;            case‘The Comfort Cruiser‘:            default:            bicycle=new ComfortCruiser();        }        Interface.ensureImplements(bicycle,Bicycle);    }};

var BicycleShop=function(){};BicycleShop.prototype={    sellBicycle:function(model){        var bicycle=this.createBicycle(model);        bicycle.assemble();        bicycle.wash();        return bicycle;    },    createBicycle:function(model){        throw new Error(‘...‘)//抽象类，声明这个方法，但不实现这个方法，直接调用会报错    }};

var AcmeBicycleShop=function(){};extend(AcmeBicycleShop,BicycleShop);AcmeBicycleShop.prototype.createBicycle=function(model){    var bicycle;    switch(model){        case‘The Speedster‘:        bicycle=new AcmeSpeedster();        break;        case‘The Lowrider‘:        bicycle=new AcmeLowrider();        break;        case‘The Comfort Cruiser‘:        default:        bicycle=new AcmeComfortCruiser();    }    Interface.ensureImplements(bicycle,Bicycle);    return bicycle;};var GeneralProductsBicycleShop=function(){};extend(GeneralProductsBicycleShop,BicycleShop);GeneralProductsBicycleShop.prototype.createBicycle=function(model){    var bicycle;    switch(model){        case‘The Speedster‘:        bicycle=new GeneralProductsSpeedster();        break;        case‘The Lowrider‘:        bicycle=new GeneralProductsLowrider();        break;        case‘The Comfort Cruiser‘:        default:        bicycle=new GeneralProductsComfortCruiser();    }    Interface.ensureImplements(bicycle,Bicycle);    return bicycle;};//需要时任意调用即可//var bobCruisers=new GeneralProductsBicycleShop();//var yourSecondNewBike=bobCruisers.sellBicycle(‘The Lowrider‘);