Class vs ID
Cascading Style Sheets (CSS) yog ib hom lus uas piav txog qhov zoo thiab kev tsim ntawm cov ntaub ntawv uas siv cov lus cim. CSS yog dav siv los tsim cov nplooj ntawv web sau hauv HTML. CSS tso cai qhia koj tus kheej cov neeg xaiv cov style ntxiv rau kev siv cov qauv rau HTML ntsiab lus. Qhov no yog ua tiav siv tus ID thiab cov chav xaiv xaiv. Thaum qhia txog tus qauv rau ib lub cim tshwj xeeb, tus ID xaiv tau siv. Thaum qhia txog tus qauv rau ib pawg ntawm cov ntsiab lus, tus xaiv chav kawm yog siv.
Hnub yog dab tsi?
Nyob hauv CSS, Class selector siv tau los siv koj tus kheej style rau ib pawg ntawm cov ntsiab lus. Cov chav xaiv xaiv yog siv los siv cov qauv tshwj xeeb rau cov txheej txheem nrog tib chav kawm. Hauv CSS, tus xaiv chav kawm raug txheeb xyuas los ntawm qhov nres tag nrho (.). Hauv qab no yog ib qho piv txwv ntawm tus xaiv chav kawm uas tau teev tseg hauv CSS.
.my_class {
xim: xiav;
font-yuag: bold;
}
HTML tuaj yeem xa mus rau cov chav kawm uas tau teev tseg hauv CSS los ntawm kev siv chav kawm tus cwj pwm raws li qhia hauv qab no.
No yog kuv formatting
No yog kuv formatting dua
Raws li tau qhia saum toj no, tib chav kawm yuav siv tau rau ntau lub ntsiab lus thiab ib lub caij tuaj yeem siv ntau chav kawm. Thaum ntau chav kawm siv nyob rau hauv tib lub caij, cov chav kawm tau muab tso rau hauv chav kawm tus cwj pwm delimited los ntawm qhov chaw raws li qhia hauv qab no.
No yog kuv formatting siv ob chav kawm
Dab tsi yog tus ID?
Hauv CSS, tus neeg xaiv ID tuaj yeem siv los siv koj tus kheej style rau ib qho tshwj xeeb. Hauv CSS, tus neeg xaiv ID raug txheeb xyuas los ntawm hash (). Hauv qab no yog ib qho piv txwv ntawm tus neeg xaiv ID uas tau teev tseg hauv CSS.
my_ID {
xim: liab;
text-align:right;
}
HTML tuaj yeem xa mus rau tus ID xaiv tau teev tseg hauv CSS los ntawm kev siv tus cwj pwm id raws li qhia hauv qab no.
No yog kuv formatting daim ntawv xaiv tus ID
IDs yog qhov tshwj xeeb. Yog li txhua lub caij tsuas muaj ib tus ID xwb thiab txhua nplooj ntawv tuaj yeem muaj tib lub ntsiab lus nrog tus ID tshwj xeeb. IDs muaj cov yam ntxwv tseem ceeb uas tuaj yeem siv nrog browser. Yog tias nplooj ntawv URL muaj tus nqi hash (piv txwv li https://myweb.commy_id) tus browser yuav sim nrhiav qhov chaw nrog tus ID “my_id” thiab scroll lub vev xaib kom pom cov khoom ntawd. Qhov no yog ib qho laj thawj vim li cas nplooj ntawv yuav tsum muaj ib lub ntsiab lus nrog tus ID tshwj xeeb, kom tus browser tuaj yeem nrhiav cov khoom ntawd.
Qhov txawv ntawm Chav Kawm thiab ID yog dab tsi?
Txawm hais tias ob qho tib si Class selector thiab ID selector tuaj yeem siv los siv koj tus kheej style rau cov ntsiab lus hauv nplooj ntawv web, lawv muaj qee qhov sib txawv tseem ceeb. Class selector siv tau los siv koj tus kheej style rau ib pawg ntawm cov ntsiab lus, thaum tus ID selector yog siv los siv cov style rau ib qho, tshwj xeeb. Thaum siv IDs, txhua lub caij tsuas muaj ib tus ID xwb thiab txhua nplooj ntawv tuaj yeem muaj tib lub ntsiab lus nrog tus ID tshwj xeeb, tab sis Chav kawm tuaj yeem siv rau ntau lub ntsiab lus thiab ib lub ntsiab lus tuaj yeem siv ntau Chav. Tsis tas li ntawd, ID tuaj yeem siv los rub ib nplooj ntawv tuaj yeem tso saib cov khoom nrog tus ID, tab sis qhov no tsis tuaj yeem ua tau nrog tus xaiv chav kawm.
