Kev hloov pauv yog ib lub ntsiab lus tseem ceeb tshaj plaws hauv kev siv computer. Lawv khaws cov ntaub ntawv xws li ntawv, tus lej, lo lus, kab lus, muaj tseeb/tsis tseeb, thiab ntau ntxiv. Qhov no yuav muab koj cov lus qhia rau hauv kev siv hloov pauv hauv Java. Nws tsis yog lub hom phiaj ua tiav cov lus qhia, tab sis yog lub pob zeb mus rau hauv lub ntiaj teb ntawm lub khoos phis tawj programmer.
Cov kauj ruam
Kauj Ruam 1. Tsim qhov program Java yooj yim
Piv txwv tau muab hu ua Hello.java:
pej xeem chav Nyob Zoo {pej xeem zoo li qub tsis muaj dab tsi tseem ceeb (Txoj hlua args) {System.out.println ("Nyob Zoo Ntiaj Teb!");
Kauj Ruam 2. Scroll mus rau qhov chaw uas koj xav ntxig qhov sib txawv
Nco ntsoov: Yog tias koj tso qhov sib txawv hauv chav kawm tseem ceeb, koj tuaj yeem siv nws nyob txhua qhov chaw. Xaiv hom kev hloov pauv uas koj xav tau.
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Cov ntaub ntawv cov lej: Siv los khaws cov lej sib xws xws li 3, 4, -34 thiab lwm yam
- byte ib
- luv
- int ib
- ntev
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Floating Point cov ntaub ntawv hom: Siv los khaws cov lej uas muaj feem me me ib yam li 3.479
- ntab
- ob npaug
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Cov ntaub ntawv tus yam ntxwv: Siv los khaws cov cim zoo li 's', 'r', 'g', 'f' thiab lwm yam
char
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Hom ntaub ntawv Boolean: tuaj yeem khaws ob qho ntawm ob qhov tseem ceeb: muaj tseeb thiab tsis tseeb
boolean
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Hom ntaub ntawv siv: Siv los khaws cov neeg ua pov thawj rau cov khoom
- Hom Array
- Hom hom zoo li txoj hlua
Kauj Ruam 3. Tsim kom muaj qhov sib txawv
Nov yog cov piv txwv ntawm kev tsim thiab muab tus nqi rau txhua hom.
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int someNumber = 0;
3184483 ib -
ob qho tib siDouble = 635.29;
3184483 ib -
ntab someDecimal = 4.43f;
3184483 ib -
boolean trueFalse = muaj tseeb;
3184483 ib -
String someSentence = "Kuv tus dev noj cov khoom ua si";
3184483b 5 -
char someChar = 'f';
3184483 ib
Kauj Ruam 4. Nkag siab tias qhov no ua haujlwm li cas
Nws yog qhov pib "hom npe = tus nqi".
Kauj Ruam 5. Tiv thaiv qhov hloov pauv los ntawm kev kho tom qab, xaiv tau, los ntawm kev ntxiv "hom kawg lub npe" nruab nrab ntawm kab lus nyob hauv kab thib ob ntawm koj cov cai (pej xeem zoo li qub tsis muaj dab tsi tseem ceeb)
kawg int someNumber = 35; Ntxiv qhov 'kawg' ntawm no txhais tau tias qhov sib txawv 'someNumber' tsis tuaj yeem hloov pauv tom qab
Lub tswv yim
- Txhua qhov sib txawv hauv qhov kev zov me nyuam yuav tsum muaj lub npe tshwj xeeb lossis koj yuav tsoo qhov yuam kev.
- Hauv Java, txhua kab lus qhia yuav tsum xaus rau hauv;
- Cov sib txawv sib txawv tuaj yeem muaj tib lub npe hauv qee qhov xwm txheej. Piv txwv li: Qhov sib txawv hauv txoj hauv kev tuaj yeem muaj lub npe zoo ib yam li qhov piv txwv piv txwv.
