Sens
Charactersincludeletters, numéros, arithmeticsymbols, punctuationmarksandothersymbols, aswellassomefunctionalsymbols.Thecharactersarestoredinthecomputer, andthecorrespondingbinarycodesrepresentingthecharactersshouldbespecified.Theselectionofthecodeshouldbeconsistentwiththespecificationsoftherelevantperipheralequipment.Theseperipheraldevicesincludetheinputandoutputofthekeyboardconsole, theoutputoftheprinter, andsoon.Whenacharacterisinput, itmustbeautomaticallyconvertedintoabinarycodeandstoredinthemachine; whenoutput, thebinarycodeinthecomputerisautomaticallyconvertedintoacharacter, andtheconversionbetweenthetwoisrealizedbyperipheralequipment.Characteristhesmallestdataaccessunitinthedatastructure.Acharacterisusuallyrepresentedby8binarybits (abyte), buttherearealsoafewcomputersystemsthatuse6binarycharacterrepresentations.Thesizeofthecharactersetinasystemiscompletelydeterminedbythesystemitself.Thenumberofcharactersavailableforthecomputerisgenerally128to256 (excludingChinesecharacters) .Aftereachcharacter entre dans l'ordinateur, il sera converti en un nombre binaire de 8 bits. Différents systèmes informatiques et différentes langues ont des plages de caractères différentes.
InASCIIencoding, anEnglishalphabetcharacterneeds1bytetostore.InGB2312encodingorGBKencoding, 2bytesareneededtostoreaChinesecharactercharacter.InUTF-8encoding, anEnglishalphabetcharacterneeds1bytetostore, andaChinesecharactercharacterneeds3to4bytestostore.InUTF-16encoding, storageofanEnglishalphabetcharacteroraChinesecharactercharacterrequires2bytes (someChinesecharactersintheUnicodeextensionarearequire4bytestostore) .InUTF-32encoding, thestorageofanycharacterintheworldrequires4bytes.
Expression
Les caractères sont des entités abstraites qui peuvent être représentées à l'aide d'une variété de différents schémas de caractères ou de pages de codes.
Rôle
L'application prenant en charge le Microsoft CommonLanguage Runtime utilise le codage pour mapper la représentation des caractères à partir du schéma de caractères natifs vers d'autres schémas.
Computersandcommunicationequipmentwillusecharacterencodingtoexpresscharacters.Itmeansassigningacharactertosomething.Traditionally, itrepresentsanentirenumberofbitsequences.Inthisway, itcanbetransmittedthroughthenetworkandisalsoeasytostore.TwocommonexamplesareASCIIandUTF-8forUnicode.AccordingtoGoogle'sstatistics, UTF-8isthemostcommonlyusedencodingmethodforwebpages.Comparedwithmostcharacterencodingsthatcorrespondtoanumberorbitstring, Morsecipherusesasequenceofelectronicpulsesofindefinitelengthtorepresentcharacters.