Video: Dab tsi yog qhov default access specifier ntawm chav kawm hauv Java?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cov default specifier nyob ntawm cov ntsiab lus. Rau chav kawm , thiab interface declarations, cov ua ntej yog pob khoom ntiag tug. Qhov no ntog ntawm kev tiv thaiv thiab ntiag tug, tso cai xwb chav kawm nyob rau hauv tib lub pob nkag mus . Rau interface cov tswv cuab (teb thiab cov txheej txheem), cov default access yog pej xeem.
Ib yam li ntawd, nws tau nug, dab tsi yog qhov default access specifier hauv java?
Java muab ib default specifier uas yog siv thaum tsis muaj nkag mus modifier tam sim no. Txhua chav kawm, teb, txoj kev lossis tus tsim tsim uas tsis tau tshaj tawm nkag mus modifier tsuas yog siv tau los ntawm cov chav kawm hauv tib lub pob. Cov ua ntej modifier tsis siv rau cov teb thiab cov txheej txheem hauv ib qho interface.
Dab tsi yog qhov hloov pauv nkag hauv Java? A Java access modifier qhia tau cov chav kawm twg nkag mus ib tug muab chav kawm thiab nws cov teb, constructors thiab txoj kev. Access modifiers muaj peev xwm raug teev cais rau ib chav kawm, nws cov constructors, teb thiab txoj kev. Cov chav kawm, teb, tus tsim thiab cov txheej txheem tuaj yeem muaj ib qho ntawm plaub qhov sib txawv Java access modifiers : private.
Ua li no, dab tsi yog qhov kev hloov pauv hloov pauv hauv Java hauv chav kawm?
Lub Default access modifier yog pob -private (i.e DEFAULT) thiab nws tsuas yog pom los ntawm tib yam pob . Default access modifier - Yog tias ib chav kawm tsis muaj kev hloov pauv (lub neej ntawd, tseem hu ua pob -private), nws pom tsuas yog hauv nws tus kheej pob (cov pob khoom muaj npe ntawm cov chav kawm muaj feem xyuam).
Dab tsi yog hom ntaub ntawv nyob hauv Java?
Nws tus nqi yam tsawg kawg nkaus yog - 2, 147, 483, 648 thiab tus nqi siab tshaj plaws yog 2, 147, 483, 647. Nws ua ntej tus nqi yog 0. Tus int hom ntaub ntawv feem ntau yog siv los ua ib qho hom ntaub ntawv default rau qhov tseem ceeb tshwj tsis yog tias tsis muaj teeb meem txog kev nco. Piv txwv li: int a = 100000, int b = -200000.
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 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
Dab tsi yog qhov tseem ceeb ntawm IT Essentials chav kawm muaj nyob hauv Cisco Academy cov ntaub ntawv kawm?
Dab tsi yog qhov tseem ceeb ntawm IT Essentials chav kawm muaj nyob hauv Cisco Academy cov ntaub ntawv kawm? Nws qhia cov neeg kawm paub txog cov hauv paus ntawm lub computer hardware thiab software. Lub zej zog IT twg yog kev sau cov peev txheej tsim los rau cov tib neeg uas xav tsim kev txawj ntse thiab ua raws li Cisco ntawv pov thawj?