Qhov Tseem Ceeb Qhov txawv - qhov kawg vs thaum kawg vs qhov kawg hauv Java
Qhov kawg, kawg thiab kawg yog cov ntsiab lus siv hauv Java programming. Qhov kawg yog lo lus tseem ceeb. Nws tuaj yeem siv rau kev hloov pauv, txoj hauv kev lossis cov chav kawm. Cov kev hloov pauv tau tshaj tawm tias qhov kawg yuav tsum tau pib ib zaug xwb. Lawv hloov tsis tau. Raws li Java yog ib hom lus uas txhawb nqa Object Oriented Programming, nws tso cai rau tsim cov chav kawm los ntawm cov chav kawm uas twb muaj lawm los txhim kho code reusability. Qee zaum, nws yuav tsim nyog kom tsis txhob siv cov chav kawm uas twb muaj lawm. Rau qhov ntawd, zaum kawg siv tau. Hauv programming, tuaj yeem ua yuam kev, thiab nws yog ib qho tseem ceeb uas yuav tsum tau tswj lawv kom ua tiav qhov program kom raug. Qhov kawg yog ib txoj kev hu ua los ntawm tus neeg khaws khib nyiab. Yog li tag nrho cov lus no muaj lub ntsiab lus sib txawv raws li. Qhov kawg yog lo lus tseem ceeb uas tiv thaiv kev hloov pauv hloov, zam txoj kev overriding thiab tsis txhob ncua cov chav kawm. Qhov kawg yog ib qho thaiv hauv kev zam kev tuav, uas yuav ua tiav txawm tias qhov kev zam raug pov los yog tsis. Qhov kawg yog ib txoj hauv kev, hu ua los ntawm cov khoom khib nyiab ua ntej nws rhuav tshem cov khoom tag nrho. Qhov ntawd yog qhov sib txawv tseem ceeb kawg thaum kawg thiab ua tiav hauv Java.
Java kawg yog dab tsi?
Qhov kawg yog lo lus tseem ceeb hauv Java. Raws li Java txhawb nqa Object Oriented programming, cov subclasses tuaj yeem siv qhov sib txawv thiab cov qauv ntawm cov chav kawm uas twb muaj lawm. Cov chav kawm uas twb muaj lawm yog cov superclass thaum cov chav kawm tshiab yog cov subclass. Yog tias tus programmer xav tiv thaiv qhov sib txawv tuaj yeem nkag tau los ntawm lwm chav kawm, nws tuaj yeem tshaj tawm qhov sib txawv li 'qhov kawg'. Piv txwv li, xav tias muaj qhov sib txawv li p. Nws tau tshaj tawm tias qhov kawg thiab pib ua tus nqi 10.e.g. kawg int p=10. Yog tias tus nqi p hloov dua siab tshiab rau 20, nws yuav ua rau lub sijhawm ua yuam kev. Lo lus tseem ceeb kawg txwv tsis pub hloov tus nqi ntawm qhov sib txawv.
Ib chav kawm siv tau ib txoj hauv kev uas twb muaj nyob rau hauv chav kawm uas twb muaj lawm. Xav tias muaj ib chav kawm hu ua B uas muaj cov qauv qhia (). Cov chav kawm tshiab yog C, thiab nws txuas mus rau chav kawm B. Yog tias chav kawm C tseem muaj ib txoj hauv kev hu ua display(), ces tus thawj chav kawm B zaub() txoj kev yog overridden. Yog tias tus programmer xav kom tsis txhob muaj txoj hauv kev los ntawm overriding, ces nws tuaj yeem siv lo lus tseem ceeb thaum kawg. e.g. zaum kawg void display(){ }. Ua ib txoj hauv kev kawg ua kom paub meej tias txoj haujlwm ntawm txoj kev yuav tsis raug hloov pauv.
Daim duab 01: kawg, kawg thiab kawg
Nws tseem tuaj yeem siv lo lus kawg rau hauv chav kawm. Cov chav kawm tshiab tsis tuaj yeem tau txais qhov hloov pauv thiab cov txheej txheem ntawm chav kawm kawg. Qhov no yuav pab tau kom muaj kev ruaj ntseg. Raws li cov chav kawm raug txwv los ntawm kev siv los ntawm subclasses, cov ntaub ntawv raug tiv thaiv.
kawg hauv Java yog dab tsi?
Hauv kev ua haujlwm, tuaj yeem ua yuam kev. Qhov yuam kev tuaj yeem ua rau cov khoom tsis raug lossis txiav tawm qhov kev ua tiav ntawm qhov program. Nws yog ib qho tseem ceeb uas yuav tsum tau siv qee yam txheej txheem los tiv thaiv cov txiaj ntsig tsis tau xav txog. Qhov yuam kev tuaj yeem yog ob hom. Lawv yog compiled lub sij hawm yuam kev thiab runtime yuam kev. Compile lub sij hawm yuam kev tshwm sim vim syntactical yuam kev. Qee qhov kev sib sau ua ke-lub sij hawm yuam kev yog ploj lawm cov semicolon, ploj lawm curly braces, mis spelling identifiers, keywords thiab undeclared variables. Lub compiler yuav tsis tsim cov ntaub ntawv.class kom txog thaum cov kev ua yuam kev no raug kho.
Qee zaum yuav muaj cov kev pab cuam uas suav tau zoo tab sis muab cov khoom tawm tsis raug. Lawv hu ua runtime yuam kev. Qee qhov yuam kev runtime feem ntau yog dhia tus lej los ntawm xoom thiab nkag mus rau lub ntsiab lus uas tsis muaj kev cia siab ntawm ib qho array. Cov kev ua yuam kev no yuav tsis ua rau muaj kev ua yuam kev ntawm lub sijhawm sau, tab sis cov zis tsis raug. Ib qho kev zam yog ib qho mob uas tshwm sim los ntawm kev ua haujlwm yuam kev hauv qhov program.
Thaum muaj qhov yuam kev runtime, Java tsim ib qho khoom tshwj xeeb thiab pov nws. Yog tias qhov kev zam tsis raug ntes tau zoo, nws yuav tso tawm cov lus yuam kev thiab yuav txiav qhov program. Yog hais tias tus programmer xav mus txuas ntxiv qhov kev ua tiav ntawm qhov kev pab cuam nrog rau qhov seem ntawm cov cai, nws yuav tsum ntes cov khoom tshwj xeeb thiab tso saib cov lus tsim nyog rau kev kho. Cov txheej txheem no hu ua kev tuav pov hwm kev zam.
Hauv Java, sim yog siv rau tus lej uas yuav ua rau muaj qhov yuam kev thiab pov qhov kev zam. Kev ntes yog siv los tswj qhov kev zam pov tseg los ntawm kev sim thaiv. Nws tuaj yeem muaj ntau cov lus qhia. Cov nqe lus kawg tuaj yeem siv los daws qhov kev zam uas tsis raug ntes los ntawm ib qho ntawm cov lus ntes yav dhau los. Qhov kawg thaiv yuav raug txiav txim seb qhov kev zam raug pov los yog tsis. Xa mus rau qhov piv txwv.
int p=10, q=5, r=5;
int answer;
try{
answer=p / (q – r);
}
catch (ArithmeticException e){
System.out.println("Div los ntawm xoom");
}
kawg{
System.out.println("Thaum kawg thaiv tau ua tiav");
}
Raws li cov piv txwv saum toj no, tus nqi p muab faib los ntawm xoom, thiab nws yuav ua rau muaj kev zam. Yog li ntawd, nws yog ntes tau los ntawm catch nqe lus. Nws yuav luam cov lus, faib los ntawm xoom. Qhov kawg thaiv yuav raug txiav txim seb qhov kev zam tshwm sim los yog tsis. Tom qab Muab faib los ntawm xoom cov lus, cov lus hauv qhov kawg thaiv yuav tso tawm. Yog li ntawd, thaum kawg yog ib qho thaiv siv nyob rau hauv kev zam tuav.
Dab tsi yog qhov kawg hauv Java?
Hauv OOP, cov khoom raug tsim siv cov chav kawm. Tus txheej txheem constructor tuaj yeem pib qhov khoom thaum nws tshaj tawm. Cov txheej txheem hu ua initialization. Java kuj muaj lub tswv yim hu ua finalization. Java runtime yog ib qho khoom siv khib nyiab tsis siv neeg. Nws cia li tso tawm cov peev txheej nco tau siv los ntawm cov khoom. Tus neeg khaws khib nyiab hu txoj kev no ua ntej rhuav tshem cov khoom.
Qee yam khoom yuav tuav tsis yog khoom siv. Ib qho piv txwv yog ib daim ntawv piav qhia. Hauv cov xwm txheej no, tus neeg khaws khib nyiab hu rau txoj kev ua tiav. e.g. ua kom tiav (). Txoj kev no ua kom huv si ua ntej cov khoom khib nyiab sau.
Dab tsi yog qhov Zoo sib xws Ntawm qhov kawg kawg thiab qhov kawg hauv Java?
Txhua qhov kawg, kawg thiab kawg hauv Java yog siv hauv Java programming
Qhov txawv ntawm qhov kawg kawg thiab qhov kawg hauv Java yog dab tsi?
kawg vs kawg vs kawg |
|
| kawg | Qhov kawg yog lo lus tseem ceeb hauv Java uas tiv thaiv kev hloov pauv hloov pauv, zam txoj kev hla dhau thiab tsis txhob ncua cov chav kawm. |
| kawg | Thaum kawg yog qhov thaiv hauv Java kev zam kev tuav, uas yuav ua tiav txawm tias qhov kev zam raug pov tseg lossis tsis ua. |
| finalize | Qhov kawg yog ib txoj hauv kev hauv Java, hu ua los ntawm tus neeg khaws khib nyiab ua ntej nws rhuav tshem cov khoom tag nrho. |
| kawg | Qhov kawg yog muaj feem xyuam rau qhov sib txawv, txoj hauv kev thiab cov chav kawm. |
| kawg | Thaum kawg yog siv tau nrog sim thiab ntes cov blocks. |
| finalize | Qhov kawg siv tau rau cov khoom. |
Summary – kawg vs thaum kawg vs finalize hauv Java
Qhov kawg, kawg thiab kawg yog cov ntsiab lus siv hauv Java Programming. Lawv cov lus zoo ib yam, tab sis lawv muaj qhov sib txawv. Qhov kawg yog lo lus tseem ceeb uas tiv thaiv kev hloov pauv hloov pauv, zam txoj kev overriding thiab tsis txhob ncua cov chav kawm. Qhov kawg yog ib qho thaiv hauv kev zam kev tuav, uas yuav ua tiav txawm tias qhov kev zam raug pov los yog tsis. Qhov kawg yog ib txoj hauv kev, hu ua los ntawm cov khoom khib nyiab ua ntej nws rhuav tshem cov khoom kom tiav. Qhov ntawd yog qhov txawv ntawm qhov kawg, kawg thiab kawg hauv Java Programming.
Download the PDF of final vs kawg vs finalize in Java
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