javascript面向对象特性实现封装继承

Javascript作为弱类型语言，和Java、php等服务端语言相比，拥有极强的灵活性。webjavascript时，可以选择面向过程的方式编程，显得高效；但要，Javascript原生语法中没有提供表述面向对象语言特性的关键字和语法（如extends、implement都将带来一些额外的内存开销，有些可以忽略不计，有些则是得不偿失，需要注意。varbook=varCOUNT=functioncheckISBN(isbn){returntrue;}varctor=function(id,name,isbn){var_id,_name,_isbn}this.getId=function(){return_id;}this.setName=_name=}this.getName=function(){returnname;}this.setIsbn=_isbn=}this.getIsbn=function(){returnisbn;}}}}

returnCOUNT;book.buyCount=function(count){returncount;}totype={}}varb=newbook();*varInterface=function(name,method){if(arguments.length<2){thrownew}=name;this.method=[];for(vari=if(typeofmethod[i]!=='string'){thrownewError("xxx");}}}//publicstaticInterface.ensureImplement=function(object){for(vari=0;i<arguments.length;i++){varinterface=thrownewError("xxx";)}for(varj=0;j<ingerface.method.length;j++){varmethod=interface.method[j];if(!object[method]||typeofobject[method]!==='function'){thrownewError("xxx");}}}}functiontestInterface=function(mapInstance){}functionMap(name){=name;this.getData=function(){};this.getResults=}varmapInstance=newMap("test");*//function(name){=}functionthis.book=book;}extend(Dtotype.getBooks=function(){returnthis.book;}vard=newDesign("tim","test");functionextend(superclass,subclass){varF=function(){};totype=newF();totype.constructor=superclass;}}//functionclone(superclass){varF=function(){};returnnewF();}var=getName:function(){;}varDesion=clone(Desion.books写给大家看的设计书"];Desion.getBooks=function(){return}//varMimin=function(){};Mtotype={name:getName:function(){returnthi