Endless for (Java) umjikelezo

Ngo-Java, njengase cishe kunoma iyiphi ulimi lokwakha izinhlelo, kukhona amathuluzi iphindaphindwe multiple of ingxenye ethize yalokho ikhodi, noma, njengoba zibizwa kanjalo, imijikelezo. Izihibe Java amelwa opharetha, njengoba i-kuyilapho, kanye nezinhlobonhlobo zazo. Ngokuvamile, imijikelezo asetshenziselwa ukudlula afanayo eyodwa-ntathu multi-ntathu iterable izakhiwo idatha (kuhlanganise namaqoqo) ukuthola izinto ezithile kanye nemisebenzi eminye nabo. Nokho, lokhu akukhona indlela kuphela usebenzisa ithuluzi ezifana umjikelezo we-Java. Izibonelo ukusetshenziswa yayiyobizwa actuated njengoba bacabangela.

Loop The ngenkathi Java: incazelo nezibonelo

Inqubomgomo ebalulekile umjikelezo opharetha Java isikhashana. Amazwibela wekhodi ebiyelwe emzimbeni wakhe, ukuze ziphindwe nje inkulumo ethi isimo, ebiyelwe kubakaki ngemva kwalo, wanelise inani elingqondo TRUE. Ifomu jikelele isitatimende lapho simi ngale ndlela:

kuyilapho (isimo) {

// iluphu umzimba

}

Uma ukubaluleka kwezimiso okunengqondo ayeka ukuba khona kweqiniso, mina siboshwa kumjikelezo ikhodi umzimba ngeke usaba kwenziwe nokulawula ezizophasiswa ngokushesha emva kokufinyelela umugqa. Uma wazi ukuthi okuvalelwe opharetha eyodwa kuphela, besokunxele kungenziwa ukhishwa inyumbazana, kodwa kubhekwa ifomu enhle, uma ngaso sonke isikhathi. Isibalo ngaphezulu sibonisa ukugeleza idayagramu ukusebenza kwe-opharetha.

Ngokucaca, ake sibheke isibonelo, kuboniswe kulo mdwebo ongezansi:

Wamemezela count variable ekuqaleni kusethelwe ku- 1. Ngokulandelayo, sibona inkulumo okunengqondo ebiyelwe abakaki emva igama lika-opharetha. Kuyiqiniso, okungukuthi, ubuyele ukubaluleka kweqiniso, inqobo nje ukubaluleka ukubala variable kuncane noma elilingana 10. loop nge pass ngamunye (kuphindelelwa) ukubaluleka variable is abaqhubeke-1 futhi uboniswa esikrinini console. Qaphela ukuthi uma inani le-variable ifinyelele 11, umjikelezo kuyekile ukusebenza.

Uma ukubaluleka count ekuqaleni elilingana 11, isimo iluphu kungaba amanga, futhi lolu hlelo ngeke, bebadzimate emzimbeni wakhe.

Kuyaphawuleka ukuthi i-syntax Java evumela ukusetshenziswa isitatimende ngesikhathi ngaphandle komzimba. Nasi isibonelo. Ake sithi sinalo eziguquguqukayo ezimbili i = 100 j = 200, sibhekene umsebenzi isofthiwe ukubala isilinganiso sabo - ungasebenzisa "eziyize» ngenkathi:

kuyilapho (++ i <- j);

Ngenxa yalokho, ukubaluleka yimiphi eziguquguqukayo ezimbili kuyoba ulingana isilinganiso namagugu abo kokuqala. Njengoba ubona, umjikelezo wasebenza kahle ngaphandle komzimba, futhi kwenziwe zonke izenzo ezidingekayo kule isisho esinombandela.

Umjikelezo do-ngenkathi

Esikhathini esidlule, uma isisho esinombandela ekuqaleni wabuya zamanga, bese isimiso bayinake umzimba loop futhi waqhubeka. Nokho, ngokuvamile kuba khona izimo lapho kubulawa ikhodi eziqukethwe umzimba loop, qiniseka okungenani esisodwa, kungakhathaliseki ukuthi iqiniso esinombandela. Ngamanye amazwi, kwenzeka ukuthi uhlole ubuqiniso isisho esinombandela ayidingekile ekuqaleni kanye ekupheleni umjikelezo. Lokhu kusebenza anganikeza uhlobo iluphu ngenkathi ebizwa do-isikhashana. It has ifomu elilandelayo:

ukwenza {
// iluphu umzimba

} Lapho (isimo);

Njengoba singabona, wokuqala, umjikelezo ukubulawa umzimba, bese kuphela ihlolwe isimo kuyiqiniso - nokunye kuphindelelwa ngamunye.

Ikhodi ngenhla, uyazigcwalisa cishe okufanayo njengoba kwenzeka nge ngenkathi ezivamile. Nokho, uma senza i-value of ukubala 11, umzimba iluphu namanje ukuhlangabezana kanye, ngaphambi opharetha ungaqinisekisa iqiniso okuvela kuyo le nkulumo.

Incazelo kanye izibonelo - Java umjikelezo

Ukuze umjikelezo kuyindlela okudingeka bashintshashintshe ngayo futhi esebenza kahle ngokolimi eJava. Kuze version wesihlanu Java SDK kwaba ifomu elilodwa kuphela yendabuko ngoba amazwi, futhi ngemva entsha - ngayinye. Kule ngxenye, sizokwenza ukuhlola ngendlela evamile opharetha. I-Java iluphu simiswe ngalendlela lelandzelako:

Ngaphambi ikhodi control kuzodluliselwa kumjikelezo wokuqala initializes i variable, silokhu sikhonza njengamaphayona esikhathi counter. Ngaphezu kwalokho, isisho esinombandela ihloliwe, lapho counter uqhathaniswa inani elithile, futhi uma ubuyela kweqiniso, umzimba uyabulawa. Khona-ke, inani ukubala sishintshwe isinyathelo elinqunyiwe, futhi futhi ihlolwe isisho esinombandela nokunye kuze isimo kungamanga. Block umdwebo ngezansi sibonisa zonke izigaba umjikelezo.

Ukuze uthole ukuqonda kangcono sikunikeza isibonelo sendlela umjikelezo-Java:

Siyabona ukuthi ngefonti loopVal lisetshenziswa njengedivaysi esiphikisayo. Ngemva kuphindelelwa ngamunye, inani walo luyokhula-1, futhi ngeke kwenzeke kuze kube yilesi sikhathi, aze afinyelele 11. Qaphela ukuthi variable control kungenziwa limenyezelwe ngaphandle ngoba amazwi, kodwa uma ungafuni ukusebenzisa lolu variable kuphi ngaphandle emjikelezweni, kungcono kuthiwe ngqo esitatimendeni. Khumbula ukuthi kwenombolo limenyezelwe isitatimende has a ububanzi ngaphakathi kulo mjikelezo efanayo.

Kunezikhathi lapho ufuna ukumemezela amaningi ukulawula iluphu onhlobonhlobo. Ukuze Java iluphu ikuvumela ukuba ucacise eziguquguqukayo ezimbili noma ngaphezulu, kuhlukaniswe ukhefane, futhi ukwenza kanjalo kokubili Ukuqalisa zabo, futhi ngesikhathi kuphindelelwa. Leyo opharetha kuyoba okulandelayo:

ngoba (int i = 1, int j = 10; i

Ngezinye kuphindelelwa ngamunye, ukubaluleka variable i is abaqhubeke-1 futhi ukubaluleka j variable is decremented by 1. okushiwoyo eziyokhishwa inqobo nje i mkhulu noma elilingana j.

Izici isicelo isitatimende

ngoba umjikelezo design batjhuguluka lula, ngoba zonke izingxenye ezintathu (Ukuqalisa, isimo, kanye isengezo / onciphile) ayikwazi ukusetshenziswa inhloso yazo. Ngokwesibonelo, esikhundleni isisho esinombandela ne variable control kungaba ithathe yimuphi variable eziphusile.

ephumayo eziphusile = amanga;

ngoba (int i = 0 ;! ophumayo; ++ i) {

ephumayo = kweqiniso;

}

Kusibonelo esingaphezulu singabona kanjani umjikelezo umsebenzi izimele ngokuphelele kusukela variable control i futhi inani iterations lithembela ngokuphelele yisiphi isikhathi ophumayo variable azosethwa ukuthi true. Ngaphezu kwalokho i-variable control kungenziwa ngokuphelele asuswe umjikelezo, futhi ngeke kuthinte umsebenzi wakhe, ngoba (; ophumayo ;!) {}. Nakuba akusiyo indlela enengqondo kakhulu ehlelweni, kwesinye isikhathi ibe wusizo. Into esemqoka - ukuhlinzekela isimo lapho variable kuzothatha ilungelo ukuphuma ukubaluleka umjikelezo, ukuze singathwesi uvule ngawo engapheli.

Ukuze Java umjikelezo kungenzeka wamemezela futhi ngale ndlela: I-(;;) {}. Lena Isibonelo esingokoqobo an loop elingapheli nemibandela ekhethekile ka kokuphazamiseka. Mayelana kwalokho, indlela owenza lolu hlobo imijikelezo uphazamisa, sizoxoxa ngemva kwesikhashana.

Cycle ngesitayela ngayinye

Foreach Java umjikelezo njalo osetshenziselwa ekuhlungeni ezilandelanayo ngamakhono ahlukahlukene izakhi noma yimuphi izakhiwo idatha futhi enze kubo imisebenzi ethile okuphindayo. Isibonelo unikezwa yamafomu opharetha ethulwa ngezansi:

Njengoba i kuphindelelwa variable igama limenyezelwe, ngaphambilini limenyezelwe amagama afanayo emigqeni opharetha wenza i-agumenti yesibili. Igama variable ngeke yanjalo ukuthatha amagugu elementi afanayo ngamunye kuze zonke izakhi zawo ezikhishwe. Kufanele kuqashelwe ukuthi uhlobo variable kufanele kube iyahambisana uhlobo izakhi egcinwe ku array. Futhi, igama variable iyatholakala kuphela lokufunda umzamo ukushintsha ngeke kuholele ushintsho kwalesi sakhi array.

Opharetha umjikelezo kokuphazamiseka

Kunezinhlobo ezintathu umjikelezo opharetha uyangenela: ikhefu, ukubuya futhi uqhubeke. Okokuqala okubili bayakwazi uphazamisa umjikelezo umsebenzi ngokuphelele, futhi bayaqhubeka besebenza onqamuka kuphindelelwa zamanje kuphela. Uma usebenzisa ikhodi yakho ngenhloso umjikelezo engapheli Java, laba basebenzi kumele abe khona kuwo. Cabangela isibonelo okulula usebenzisa ikhefu:

Nakuba lesi sitatimende inikezelwe okushiwoyo 11, ababulawa 8 kuphela ngoba, lapho i counter ilingana 7, isimo emsebenzini lapho umzimba has isitatimende ikhefu.

ukubuya opharetha usebenza ngendlela efanayo ne umehluko ukuthi akagcini ngokunikeza i umjikelezo okukhipha Java, kodwa futhi kusukela indlela, okuyinto ibekwe kule mjikelezo.

Ukusebenzisa ikhefu njengoba goto

Kumele kukhunjulwe ukuthi ikhefu iphazamisa kuphela umjikelezo, umzimba elithize abengumsunguli ngqo, okungukuthi, uma ulisebenzisa ku-loop isichazi, loop yangaphandle ngeke ayeke umsebenzi walo. Ukuze wenze lokhu, isitatimende ikhefu ingasetshenziswa njengendlela ifomu eziphucuzekile goto.

Kulesi samuntu, opharetha isetshenziswa ngesikhathi esifanayo ne ilebula, okuvumela ukuba ahlele hhayi kuphela okukhiphayo lomjikelezo, kodwa futhi kusuka kunoma iyiphi block ikhodi. Ilebuli is ngokufanele ngokuthi isihlonzi nge ikholoni ngemva kwalo. Ilebuli kuthiwa ekuqaleni block ikhodi ephawulwe. Ukuze ukuphazamisa ukukhishwa block alebuliwe, endaweni efanele kufanele athi: ikhefu imya_metki. Cabanga isibonelo ngezansi:

Esikhathini ikhodi, yamemezela amagama amabhlogo ezintathu ngamalebula Omunye, amabili amathathu ngokulandelana. Isitatimende ikhefu enelebuli ababili linamathele zonke amabhlogo ezintathu, kodwa senziwa uhlelo aphume amabhlogo ezintathu futhi ababili futhi sizoqhubeka ukusebenza Omunye Unit. okungukuthi ku-console sizobona imilayezo emibili: Three One.

isiphetho

Singabantu ujwayelene inkolelo yokungafi imijikelezo Java, ngenkathi futhi imisebenzi emikhulu, kanye namafomu kwabo do-isikhathi eside futhi ngayinye, ngokulandelana. Ukuze uthole ukuqonda kangcono sincoma ukwenza umzimba ukusetshenziswa kwalezi opharetha ezihlukahlukene, kanye izindlela ezahlukene uphazamisa kubo futhi bahamba ngezinyawo besuka kwenye block kwenye.