2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cov parseDouble () txoj kev Java Ob chav kawm yog ib txoj hauv kev ua hauv Java uas rov los tshiab ob npaug pib rau tus nqi sawv cev los ntawm txoj hlua uas tau teev tseg, raws li ua los ntawm tus nqi ntawm txoj kev ntawm chav kawm Ob npaug . Rov qab hom: Nws rov e ob npaug tus nqi sawv cev los ntawm txoj hlua sib cav.
Ib yam li ntawd, tib neeg nug, ob txhais li cas hauv Java?
ob npaug : Cov ob npaug hom ntaub ntawv yog a ob npaug -precision 64-ntsis IEEE 754 ntab taw tes. Nws qhov ntau ntawm qhov muaj nuj nqis yog dhau ntawm qhov kev sib tham no, tab sis yog tau teev nyob rau hauv Floating-Point Hom, Hom, thiab Qhov Tseem Ceeb ntawm ntu Java Lus Specification. Rau tus lej lej, hom ntaub ntawv no yog feem ntau yog qhov kev xaiv ua ntej.
Ib yam li ntawd, dab tsi yog ob qho zoo infinity hauv Java? Txawm hais tias nws yog tsis yooj yim sua rau lub computer kom cia sawv cev tus nqi ntawm tsis kawg hauv nco, lub Java " ob npaug "thiab "float" data-type reserves ob lub qhov nyob hauv nws qhov chaw nyob uas nkag siab los ntawm lub computer xa mus rau zoo thiab tsis zoo tsis kawg.
Kuj Paub, dab tsi yog ob npaug Min_value hauv Java?
Ob npaug . MIN_VALUE sawv cev rau tus nqi 2−1074. Qhov no yog tus nqi subnormal, thiab nws yog tag nrho cov nqi tsawg tshaj plaws uas a ob npaug tuaj yeem sawv cev. Tus nqi subnormal muaj 0 ua ntej lub ntsiab lus binary: 0.
Yuav ua li cas hloov ib txoj hlua mus rau ob zaug hauv Java?
Muaj peb txoj hauv kev hloov a Txoj hlua rau ob npaug tus nqi hauv Java , Ob npaug . parseDouble() txoj kev, Ob npaug . valueOf() txoj kev thiab los ntawm kev siv tshiab Ob npaug () constructor thiab tom qab ntawd khaws cov khoom tshwm sim rau hauv ib qho qub ob npaug teb, autoboxing hauv Java yuav hloov a Ob npaug ob leeg rau ob npaug primitive nyob rau hauv tsis muaj sij hawm.
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