Video: Lub npe chav kawm hauv Java yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Java muab ib chav kawm nrog npe Class hauv java ua . lang pob. Piv txwv ntawm cov chav kawm sawv cev chav kawm thiab interfaces nyob rau hauv ib tug khiav Java daim ntawv thov. Cov txheej txheem hauv ib qho chav kawm hauv java ua uas rov zoo li qub chav kawm yam khoom tseem hu ua Hoobkas txoj kev.
Kuj paub, dab tsi yog chav kawm hauv Java?
Cov chav kawm thiab Objects hauv Java . Cov chav kawm thiab Objects yog cov ntsiab lus tseem ceeb ntawm Object Oriented Programming uas tig mus ncig lub neej tiag tiag. Chav kawm . A chav kawm yog ib tug neeg siv daim ntawv qhia los yog tus qauv los ntawm cov khoom uas raug tsim. Nws sawv cev rau cov txheej txheem lossis cov txheej txheem uas muaj rau txhua yam khoom ntawm ib qho
vim li cas cov chav kawm lub npe tib yam li filename hauv Java? Yog tsis muaj pej xeem chav kawm ces npe file tej zaum yuav txawv ntawm cov npe hauv Java . Yog muaj pej xeem chav kawm ces nws yog yuam kom cov npe file yog ib yam raws li pej xeem chav kawm . Muaj cov tib lub npe raws li npe yog li cas JVM yuav paub qhov twg chav kawm mus thauj khoom thiab qhov twg los nrhiav qhov chaw nkag (tus qauv tseem ceeb).
Yog li ntawd, Java lub npe yog dab tsi?
Hauv Java , Siv cov chav kawm ua ntej npe raws li Class los yog Variable npe tso cai. Txawm li cas los xij, Raws li Java Cov Lus Qhia Tshwj Xeeb (§ 3.9) cov cai yooj yim rau kev sau npe hauv Java yog tias koj tsis tuaj yeem siv lo lus tseem ceeb li npe ntawm chav kawm, npe ntawm ib tug variable los yog npe ntawm ib daim nplaub tshev siv rau pob.
Puas yog cov npe hauv chav kawm sau npe Java?
Cov chav kawm npe conventions In Java , cov npe feem ntau yuav tsum yog cov npe, nyob rau hauv lub npe- rooj plaub nrog thawj tsab ntawv ntawm txhua lo lus cais peev . e.g.
Pom zoo:
Dab tsi yog qhov txawv ntawm chav kawm sab hauv thiab cov chav nested?
Cov chav kawm uas tau tshaj tawm yam tsis siv qhov zoo li qub yog hu ua chav kawm sab hauv lossis chav kawm tsis zoo li qub. Cov chav kawm Staticnested yog chav kawm zoo li lwm cov tswv cuab zoo li qub ntawm cov chav kawm sab nrauv. Txawm li cas los xij, cov chav kawm sab hauv yog khi toinstance thiab nws tuaj yeem nkag mus rau cov tswv cuab ntawm pawg enclosingclass
Dab tsi yog txheej txheem ntawm kev txhais ob lossis ntau txoj hauv kev hauv tib chav kawm uas muaj tib lub npe tab sis sib txawv tsis tshaj tawm?
Method overloading Tus kos npe ntawm ib txoj kev tsis suav nrog nws cov khoom xa rov qab los yog nws qhov kev pom los yog qhov kev zam uas nws yuav pov. Kev xyaum ntawm kev txhais ob lossis ntau txoj hauv kev hauv tib chav kawm uas qhia tib lub npe tab sis muaj qhov sib txawv yog hu ua cov txheej txheem overloading
Dab tsi yog ob chav kawm tshwj xeeb hauv hierarchy ntawm Java zam chav kawm?
Chav Kawm Exception muaj ob lub ntsiab subclasses: IOException class thiab RuntimeException Class. Hauv qab no yog cov npe ntawm feem ntau kuaj xyuas thiab tsis tau txheeb xyuas Java's Built-in Exceptions
Peb puas tuaj yeem muaj ntau chav kawm pej xeem hauv chav kawm hauv Java?
Yog, nws ua tau. Txawm li cas los xij, muaj peev xwm tsuas yog ib pawg pej xeem ib. java cov ntaub ntawv, raws li publicclasses yuav tsum muaj tib lub npe raws li cov ntaub ntawv qhov chaw. OneJava cov ntaub ntawv tuaj yeem muaj ntau chav kawm nrog kev txwv uas tsuas yog ib qho ntawm lawv tuaj yeem ua pej xeem
Chav kawm piav qhia txog tus qauv ntawm chav kawm yog dab tsi?
Nyob rau hauv object-oriented programming, ib chav kawm yog ib tug template txhais ntawm txoj kev s thiab txawv txawv s nyob rau hauv ib tug tej yam khoom. Yog li, ib yam khoom yog ib qho piv txwv tshwj xeeb ntawm chav kawm; nws muaj cov txiaj ntsig tiag tiag tsis yog hloov pauv. Cov qauv ntawm ib chav kawm thiab nws cov subclasses yog hu ua chav kawm hierarchy