Uhlelo lokuqala ku-Java - Hello World

Endaweni yentuthuko ekutadisheni ulimi wenza isicelo zayo zokuqala ukubingelela wonke. Kungakhathaliseki indawo yakho eqondile, ibinzana etholakala ngenxa uhlelo Sawubona mhlaba, kuyinto esigabeni sokuqala nentuthuko. Ukulandela isibonelo isicelo esilula Java.

Lungiselela ukwakha uhlelo lwakho lokuqala

Ngaphambi ukudala Sawubona yakho Umhlaba Java, udinga ukulanda futhi ufake isofthiwe. Into yokuqala uzodinga, - JDK. Lena iqoqo amathuluzi kanjiniyela. Kuyinto efiselekayo ukulanda kusuka website esemthethweni inkampani Oracle. Inguqulo yakamuva ye-Java namuhla - 8. Unjiniyela Toolkit etholakalayo thwebula futhi ukufakwa ezisekelweni cishe zonke ezaziwayo.

Khona-ke kukhona ithuba lokusebenzisa nanoma ikuphi ukuthuthukisa IDE, okungukuthi, imvelo nokuthuthukiswa, isibonelo, Eclipse kanye NetBeans, noma ukubhala ikhodi nganoma iyiphi sombhalo. Ukuze kube lula, isihloko izosebenzisa indlela elula - usebenzisa incwajana.

Hello World Java usebenzisa sombhalo elula

Kusolwa ukuthi uhlelo ifakiwe JDK. Manje udinga ukusebenzisa notebook abavamile kakhulu Windows noma gedit noma nano-Linux. Kungenzeka ukuba ulondoloze, igama ifayela, isibonelo HelloWorld.java. Khona-ke, esikhaleni sombhalo, ufake imigqa ezilula ezimbalwa ikhodi:

ekilasini HelloWorld {

}

Nangu eza kwamagama ekilasini. I-Java nezidingo ulimi, kumele abizwe iyafana ifayela ngokwayo, okuyinto. Okulandelayo kufike besokunxele, Java-syntax izakhi ekhombisa lapho ikilasi iqala kanye imikhawulo. Ngaphakathi manje kudingekile ukuchaza indlela ukuthi kuyoba yinto ukwenza:

ekilasini HelloWorld {

main (String [] args) umphakathi static uyize {

}

}

Kuyinto indlela eyinhloko iza kwethulwa yiluphi uhlelo Java. Elingukhiye yomphakathi - ukufinyelela lwewashi ukuze ukhombise ukuthi umphakathi futhi ingasetshenziswa kuphi. Ukuze ufunde ukuthi siphathwa kanjani, kungatholakala imibhalo esemthethweni ulimi.

Okulandelayo static, okusho ukuthi indlela static, ukuthi ayidaliwe zixhunywe ngekholi, futhi ekuqaleni kohlelo. Isikhala elisemqoka ibonisa ukuthi main ngeke ubuyise noma iyiphi idatha, kodwa nje into ukwenza.

String nezimpawu kubakaki [] zibonisa ukuthi indlela kungathatha kumanani ethile yokufaka, isib, ukuze kusebenziswe okwalandela. A variable igama args kunikeza ithuba ukusebenzisa ukuze idatha ngaphakathi indlela. Kuyaphawuleka ukuthi main, njengoba ikilasi, lufrenyiwe ngu besokunxele, okubonisa indawo "yabo".

Awu, manje-ke uhlala ukuze ungeze indlela ukubonisa imiphumela Uhlelo umsebenzi:

ekilasini HelloWorld {

main (String [] args) umphakathi static uyize {

System.out.println ( «! Sawubona Mhlaba»);

}

}

Lo myalo umane ubonisa string kubakaki esikrinini. Ekupheleni isitatimende isetshenziswa isemikholoni. Ngakho ngo-Java okhombisa ukuphela kwe isisho noma umugqa yekhodi. Inani okuphumayo ngenxa icashunwa.

Running nokuhlolwa isicelo sokuqala

Ukuze uqalise okuholela Hello World e-Java, udinga ukuya console. Ngo-Windows, ibizwa ngokuthi umugqa wemiyalo, futhi Linux - esigungwini. Kwake kwathi ngo-console, udinga ukuthola ifayela HelloWorld.java olulondoloziwe. Ngokwesibonelo, e-Windows, kungaba indlela C: \ Java \ Sawubona. Khona vele ufake console umyalo CD C: \ Java \ Sawubona. Zula kufolda nge ifayela hlelo, kuzomele uqale ukuguqula it bytecode. Ukuze wenze lokhu, sebenzisa isakhiwo ezilandelayo:

javac HelloWorld.java

Ngemva kwalokho kudingeka ukusebenzisa isigaba okuholela ekufeni. Ngenxa yalesi, futhi, kukhona iqembu ahlukene:

java HelloWorld.

Esikrinini console kumele kuvele umphumela Hello World ku-Java - ukubingelela wonke.

isiphetho

UHlelo Java - umsebenzi ezithakazelisayo kakhulu futhi ewusizo. Isiteji uyakwazi ukusebenzisa ku ezihlukahlukene Amadivayisi - kusukela amafoni elula mobile eziteshini iseva ezinkulu. Abaningi ezinkulu inthanethi Inthanethi njengendlela yesikhulumi main Java isetshenziswa ukucubungula izicelo iseva. Njengoba kulotshiwe ikhodi, futhi kuze kube manje ethandwa uhlelo lokusebenza Android. Futhi lo mkhuba yentuthuko, njengaye, e-Java has a ikusasa okukhulu.