Introduction
InternalcodereferstothebinarycharactercodeusedinthecomputerChinesecharactersystem.Itistheexchangecodebetweenthecommunicationinput,outputandthesystemplatform.TheinternalcodecanachieveuniversalandhighThepurposeofefficienttransmissionoftext.Forexample,whatisstoredandcalledinMSWordisinternalcodeinsteadofgraphictext.EnglishASCIIcharactersarerepresentedbyaone-byteinternalcode.Chinesecharacterssuchasthenationalstandardcharacterset,GB2312,GB12345,andGB13000allusedouble-byteinternalcodes,GB18030(27,533Chinesecharacters)double-byteinternalcodeChinesecharactersare20,902,andtheremaining6,631Chinesecharactersuseafour-byteinternalcode.
Classification
Characterencoding:Thecharacterencodingisthebinarynumbercorrespondingtothecharactersofthecharacterset.ThemostcommonlyusedcharactersetisANSI,andthebinaryencodingcorrespondingtotheANSIcharactersetisCalledANSIcode,DOSandWindowssystemsbothuseANSIcode,butthecharactercodeusedinthesystemmustundergobinaryconversion,whichiscalledsysteminternalcode.
Chinesecharacterinternalcode:ANSIcodeisasinglebyte(8-bitbinarynumber)encodingset,whichcanonlyrepresent256charactersatmost,andcannotrepresentmanyChinesecharacters.TheANSIcodeofvariouscountriesandregionsOnthebasisofthis,avarietyofdifferentChinesecharacterencodingsetsaredesignedtobeabletohandlealargenumberofChinesecharacters.ThesecodesusesinglebytetorepresentANSIEnglishcharacters(thatis,compatiblewithANSIcode),andusedoublebytestorepresentChinesecharacters.SincetherecanonlybeoneChinesecharacterinternalcodeinasystem,thecharactersofotherChinesecharacterinternalcodescannotberecognized,whichcausescommunicationinconvenience.
GBcode:GBcodeisasimplifiedChinesecharactercodingschemeannouncedbythecountryin1980,andiswidelyusedinmainlandChinaandSingapore,alsoknownasthenationalstandardcode.Thenationalstandardcodeencodes6763Chinesecharactersets,coveringmostoftheChinesecharactersinuse.
GBKcode:GBKcodeisanextendedcharacterencodingofGBcode,whichencodesmorethan20,000simplifiedandtraditionalChinesecharacters.SimplifiedversionsofWin95andWin98bothuseGBKassysteminternalcode.
BIG5code:BIG5codeisaChinesecharacterencodingfortraditionalChinesecharacters,whichiscommonlyusedincomputersystemsinTaiwanandHongKong.
HZ-koodi:HZ-koodi on kiinalainen merkkikoodi, jota käytetään laajasti Internetissä.
ISO-2022CJKcode:ISO-2022isacodingstandardestablishedbytheInternationalStandardsOrganization(ISO)forvariouslanguagecharacters.Two-byteencodingisadopted,inwhichtheChineseencodingiscalledISO-2022CN,andtheJapaneseandKoreanencodingsarecalledJPandKRrespectively.Generally,thethreearecollectivelyreferredtoastheCJKcode.TheCJKcodeismainlyusedintheInternetnetwork.
Unicodecode:Unicodecodeisalsoaninternationalstandardcode,whichusestwo-byteencodingandisnotcompatiblewithANSIcode.Itisusedinthenetwork,Windowssystemandmanylarge-scalesoftware.
Internalcodeconversion
Duetohistoricalandregionalreasons,sometimesmultipleencodingschemesappearinonetext,especiallyChinesecharacters.Sincecharactersdifferentfromthesysteminternalcodecannotbedisplayednormallyinthesystem,theinternalcodeconversionofthecharactersmustbecarriedout,thatis,thecharactersthatarenotthesysteminternalcodeareconvertedintotheinternalcodecharactersthatcanberecognizedbythesystem.NJStarissuchanexcellentsoftware.OtherssuchasSitongLifang,MagicWin98,Cross-StraitCommunication,ChineseCharacterCommunication,etc.areallsuchinternalcodeconversiontools.
Keskivuoroinen muuntaminen
Sijaintikoodin, kansallisen standardikoodin ja koneen sisäisen koodin muunnossuhde:
(1)Thelocationcodeisfirstconvertedintohexadecimalnumberrepresentation
(2)(Sijaintikoodin heksadesimaaliesitys)+2020H=kansallinen standardikoodi;
(3)kansallinen standardikoodi+8080H=koneensisäinen koodi
Esimerkki:Kiinalainen merkki"大"esimerkiksi,"大"-aluekoodi on 2083
Ratkaisu: 1. Aluekoodi on20 ja bittinumero on83
2.Thelocationnumber2083isconvertedtohexadecimalandexpressedas1453H
3 1453H+2020H=3473H, hanki kansallinen standardikoodi 3473H
4,3473H+8080H=B4F3H, hanki sisäinen koodi B4F3H
Yhteenveto:Merkkikoodauksen kaksi esitystapaa: ASCII (merkkien esitys);GB2312 (kansallinen standardikoodi, kiinalainen merkkikoodaus)
Aiheeseen liittyvät erot
1.Ulkoinen koodi on ulkomaailmasta syöttämäsi merkki.Tämän merkin syöttämisen jälkeen tuleevastaava sijaintikoodi (eli 94*94-ruudukko),kiinalainen merkki,syötetyt rivi+onsaa
2,thelocationcodecanbeconvertedintothenationalstandardcodeafterconversion(sothelocationcode→nationalstandardcodestepjustmeansconversion),
3,Thenationalstandardcodecanbeconvertedintotheinternalcode(usuallyrepresentedbyahexadecimalnumber)afterconversion.