Javascript作為弱類型語言，和Java、php等服務(wù)端語言相比，擁有極強(qiáng)的靈活性。webjavascript時，可以選擇面向過程的方式編程，顯得高效；但要，Javascript原生語法中沒有提供表述面向?qū)ο笳Z言特性的關(guān)鍵字和語法（如extends、implement都將帶來一些額外的內(nèi)存開銷，有些可以忽略不計(jì)，有些則是得不償失，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;}}}}

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