Cov txheej txheem:
Video: Dab tsi yog assert tsis null?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cov assertNotNull () txoj kev txhais tau hais tias "ib qho kev hla dhau yuav tsum tsis yog ua null ": yog null ces qhov kev xeem tsis. Txoj kev assertNull() txhais tau tias "ib qho kev hla dhau yuav tsum yog null ": yog tsis null ces qhov kev xeem tsis.
Yog li ntawd, yuav ua li cas koj lees tias Equals?
Qhia . assertEquals () txoj kev kuaj xyuas tias ob yam khoom sib npaug lossis tsis. Yog tias lawv tsis yog, qhov AssertionError tsis muaj lus raug pov tseg. Incase yog tias ob qho tib si xav tau thiab qhov tseeb qhov tseem ceeb yog null, ces txoj kev no rov qab sib npaug.
Tom qab ntawd, lo lus nug yog, yuav ua li cas tshwm sim thaum lees paub tsis ua tiav hauv Java? Yog tias kev lees paub tau qhib rau hauv JVM (ntawm tus chij -ea), AssertionError yuav raug pov tseg thaum kev lees paub ua tsis tiav . Qhov no yuav tsum tsis txhob raug ntes, vim hais tias yog ib qho kev lees paub ua tsis tiav , nws yeej txhais tau tias ib qho ntawm koj qhov kev xav txog yuav ua li cas qhov kev zov me nyuam ua haujlwm tsis raug. Kev lees paub yuav tsum tau siv los txheeb xyuas cov programming yuam kev nkaus xwb.
Tsis tas li ntawd, koj yuav siv cov lus cuav li cas?
Hauv assertFalse ,koj yog kev lees paub uas ib qho kev qhia ntsuas rau cuav . Yog hais tias nws tsis yog, ces cov lus yog tso tawm kom pom thiab cov kev lees paub ua tsis tiav. assertTrue (lus, nqi == cuav ) == assertFalse (lus, nqi); Cov no yog qhov ua haujlwm zoo ib yam, tab sis yog tias koj xav tias yuav muaj txiaj ntsig cuav ces siv assertFalse.
Dab tsi yog txoj kev sib txawv ntawm kev lees paub?
Ntawm no yog ib daim ntawv teev cov txheej txheem assert:
- assertArrayEquals()
- hais tiasEquals()
- assertTrue() + assertFalse()
- assertNull() + assertNotNull()
- assertSame() + assertNotSame()
- hais tias()
Pom zoo:
Dab tsi yog qhov uas tsis yog recursive qhovntsej thiaj tsis mob parser?
Kev kwv yees parsing yog ib daim ntawv tshwj xeeb ntawm recursive qhovntsej thiaj tsis mob parsing, qhov twg tsis muaj backtracking, yog li qhov no tuaj yeem kwv yees qhov kev tsim khoom siv los hloov cov hlua nkag. Tsis-recursive kwv yees parsing los yog rooj-tsav kuj hu ua LL(1) parser. Qhov parser no ua raws li qhov kev sib txuas ntawm sab laug (LMD)
Dab tsi yog data mining thiab dab tsi tsis yog data mining?
Cov ntaub ntawv tsuas yog ua tiav yam tsis muaj kev xav ua ntej, yog li cov ntaub ntawv los ntawm cov ntaub ntawv tsis yog los teb cov lus nug tshwj xeeb ntawm lub koom haum. Tsis yog Cov Ntaub Ntawv Mining: Lub hom phiaj ntawm Cov Ntaub Ntawv Mining yog kev rho tawm cov qauv thiab kev paub los ntawm cov ntaub ntawv loj, tsis yog kev rho tawm (tsuas yog) ntawm cov ntaub ntawv nws tus kheej
Dab tsi yog null thiab tsis null hauv SQL?
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Dab tsi yog sparse kem Dab tsi yog qhov zoo thiab qhov tsis zoo?
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Dab tsi yog qhov tsis raug thaum TV tsis qhib?
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