簡介:英文資料翻譯英文資料翻譯系別軟件與服務外包學院專業(yè)軟件技術班級0904姓名李欣學號100090590指導教師高振棟2012年4月2HTMLPAGECOULDNTDOOHSURE,IGAVEASLIGHTLYMOREINTERESTINGEXAMPLETHATDISPLAYEDTHECURRENTSERVERTIME,BUTTOBEREALLYUSEFULASCRIPTNEEDSTOPERFORMSOMEFORMOFCALCULATION,ORMANIPULATEDYNAMICINFORMATIONTOPRESENTITINSOMEINTERESTINGWAYTHELANGUAGEUSEDFORWRITINGMOSTASPPROGRAMS,ANDWHICHILLBEUSINGTHROUGHOUTTHISSERIES,ISCALLEDVBSCRIPTLIKEMOSTPROGRAMMINGLANGUAGES,VBSCRIPTLETSYOUSTOREDATAINVARIABLESAVARIABLEMAYBETHOUGHTOFSIMPLYASANAMEDLOCATIONINMEMORYWHEREDATAMAYBESTOREDVBSCRIPTISWHATISKNOWNASALOOSELYTYPEDLANGUAGE,WHICHMEANSTHATAPARTICULARVARIABLEMAYSTOREANYKINDOFINFORMATION,BEITANUMBER,APIECEOFTEXT,ADATE,ORSOMEMORECOMPLICATEDCHUNKOFDATAASOPPOSEDTOSTRICTLYTYPEDLANGUAGESWHEREYOUCANONLYSTOREONEKINDOFINFORMATIONINEACHVARIABLEBEFOREYOUCANUSEAVARIABLE,THOUGH,YOUMUSTDECLAREITTHATIS,YOUMUSTLETASPKNOWTHATYOUWANTTOCREATEAVARIABLEWITHAPARTICULARNAMELETSLOOKATABASICEXAMPLETOHELPSOLIDIFYTHESECONCEPTSINYOURMINDSAYYOUWEREWRITINGAWEBPAGETHATPERFORMEDCONVERSIONSBETWEENCELSIUSANDFAHRENHEITTEMPERATURESINCOUNTRIESWHERECELSIUSISUSED,20CISCOMMONLYACCEPTEDASTHEVALUEFORROOMTEMPERATURETHEFOLLOWINGCODECREATESAVARIABLECALLEDINTROOMTEMPC,ANDTHENASSIGNSITAVALUEOF20NEWREVISED2NDEDITIONOUTNOW“BUILDYOUROWNDATABASEDRIVENWEBSITEUSINGPHPMYSQL“FULLYUPDATEDFORPHP43INSTALLATIONINSTRUCTIONSFORMACOSXFULLINDEXPROVIDEDNEWWIDERBOOKSIZEENHANCEDFONTSNEWCOVERDESIGNLAYFLATSPINEALLCONTENTREVISITEDDOWNLOADTHEFIRST4CHAPTERSFREE
下載積分: 10 賞幣
上傳時間:2024-03-16
頁數(shù): 13
大?。?0.07(MB)
子文件數(shù):
簡介:C語言可變參數(shù)研究作者來源ZZ發(fā)表時間20061116瀏覽次數(shù)364字號大中小一.何謂可變參數(shù)INTPRINTFCONSTCHARFORMAT,這是使用過C語言的人所再熟悉不過的PRINTF函數(shù)原型,它的參數(shù)中就有固定參數(shù)FORMAT和可變參數(shù)(用””表示)而我們又可以用各種方式來調用PRINTF,如PRINTF“D“,VALUEPRINTF“S“,STRPRINTF“THENUMBERISD,STRINGISS“,VALUE,STR二實現(xiàn)原理C語言用宏來處理這些可變參數(shù)。這些宏看起來很復雜,其實原理挺簡單,就是根據參數(shù)入棧的特點從最靠近第一個可變參數(shù)的固定參數(shù)開始,依次獲取每個可變參數(shù)的地址。下面我們來分析這些宏。在VC中的STDARGH頭文件中,針對不同平臺有不同的宏定義,我們選取X86平臺下的宏定義TYPEDEFCHARVA_LIST/把VA_LIST被定義成CHAR,這是因為在我們目前所用的PC機上,字符指針類型可以用來存儲內存單元地址。而在有的機器上VA_LIST是被定義成VOID的/DEFINE_INTSIZEOFNSIZEOFNSIZEOFINT1使AP不再指向堆棧,而是跟NULL一樣有些直接定義為VOID0,這樣編譯器不會為VA_END產生代碼,例如GCC在LINUX的X86平臺就是這樣定義的在這里大家要注意一個問題由于參數(shù)的地址用于VA_START宏,所以參數(shù)不能聲明為寄存器變量或作為函數(shù)或數(shù)組類型/以下再用圖來表示PUTCHARC//照原樣輸出字符}ELSE{//按格式字符輸出數(shù)據SWITCHFMT{CASEDPRINTF“D“,INTPARGBREAKCASEXPRINTF“X“,INTPARGBREAKDEFAULTBREAK}PARGSIZEOFINT//等價于原來的VA_ARG}FMT}WHILEFMT\0PARGNULL//等價于VA_ENDRETURN}INTMAININTARGC,CHARARGV{INTI1234INTJ5678MYPRINTF“THEFIRSTTESTID“,I,JMYPRINTF“THESECENDTESTIDXJD“,I,0XABCD,JSYSTEM“PAUSE“RETURN0}在INTELWIN2KVC6的機器執(zhí)行結果如下THEFIRSTTESTI1234THESECENDTESTI12340XABCDJ5678四應用求最大值INCLUDE//不定數(shù)目參數(shù)需要的宏INTMAXINTN,INTNUM,{
下載積分: 5 賞幣
上傳時間:2024-03-16
頁數(shù): 4
大?。?0.04(MB)
子文件數(shù):