Isonjululwe: qalisa uluhlu olunamaxabiso

Ngokuqinisekileyo, masiqale ukubhala inqaku.

Ukuqala uluhlu olunamaxabiso kwiJava lumsebenzi oqhele ukufunwa ngabaphuhlisi. Kuhlala kubonwa ukuba abadwelisi beenkqubo zeJava kufuneka bajongane nemisebenzi efana nokudala uluhlu, ukongeza amaxabiso kulo kwaye emva koko benze imisebenzi kuluhlu. Le nkqubo inokudinwa ukuba ayiphathwa ngokufanelekileyo. Ke ngoko, ukuqonda iindlela ezisebenzayo zokuqalisa uluhlu olunamaxabiso kunokulungelelanisa kakhulu imisebenzi yokucwangcisa.

Inqaku liza kunika ukuqonda malunga nendlela yokuqalisa uluhlu olunamaxabiso kwiJava usebenzisa iindlela ezahlukeneyo kunye namathala eencwadi.

Ukuqaliswa Ngqo

Eyona ndlela ithe ngqo yokuqalisa uluhlu olunamaxabiso kukusebenzisa Yongeza () indlela yoluhlu lweklasi. Le ndlela yongeza into ekupheleni koluhlu.

Makhe siqwalasele umzekelo:

List<String> list = new ArrayList<>();

list.add("Element1");
list.add("Element2");
list.add("Element3");

Uluhlu olutsha ngoku luqulethe izinto ezintathu i-Element1, i-Element2, kunye ne-Element3.

Nangona kunjalo, indlela ayisebenzi kakuhle xa inani elikhulu lezinto kufuneka zongezwe. Izisombululo ezisebenzayo zixoxwa ngezantsi.

Ukusebenzisa i-Arrays.asList()

Java ibonelela Iimpawu iklasi ukusuka kuyo iJava ipakethe. Iklasi iqulethe iindlela ezahlukeneyo zokulawula ii-arrays. I njengoLuhlu() Indlela yolu didi imile kwaye ibuyisela uluhlu olusisigxina oluxhaswa luluhlu oluchaziweyo.

Masiqonde ngomzekelo:

List<String> list = Arrays.asList("Element1", "Element2", "Element3");

Indlela iyasebenza kwaye iyasebenza, kodwa uluhlu olubuyisiweyo aluguquki. Ukuba uzama ukudibanisa okanye ukususa iziqalelo kuluhlu, iya kuphosa i-java.lang.UnsupportedOperationException Exception.

Ukusebenzisa Iingqokelela

Iqoqo iklasi ye iJava iphakheji ludidi oluluncedo oluneendlela ezimileyo zokwenza imisebenzi kwizinto zeeklasi eziphumeza isakhelo sokuQokelelwa. Kukho indlela iikopi (int n, Object obj) elibuyisela uluhlu olungenakuguqulwa oluqulathe inani elichaziweyo leekopi zento echaziweyo.

Umzekelo wokusetyenziswa kwendlela:

List<String> list = Collections.nCopies(3, "Element");

Ngale ndlela, zonke izinto zoluhlu ziqaliswa kwinto ekhankanyiweyo, ngaloo ndlela zonke izinto zoluhlu ziyafana.

Ukusebenzisa iJava 8 Stream

IJava 8 yazisa entsha Ukusakaza API enokusetyenziselwa ukuqalisa uluhlu olunamaxabiso kwimigca embalwa yekhowudi.

List<String> list = Stream.of("Element1", "Element2", "Element3")
                          .collect(Collectors.toList());

Kule khowudi, Stream.of() indlela ibuyisela ulandelelwano olucwangcisiweyo lomjelo elineziqalelo ezingamaxabiso akhankanyiweyo. Ukuqokelela () indlela yokusebenza kwetheminali eqokelela isiphumo kwizakhiwo ezahlukeneyo zedatha kwaye apha iqokelela izinto zomjelo kuLuhlu.

isiphelo

Ke ezi ziindlela ezimbalwa zokuqalisa uluhlu olunamaxabiso kwiJava. Ngelixa ujongana noluhlu kwiJava, abasebenzisi baneendlela ezahlukeneyo zokukhetha ngokuxhomekeke kwiimfuno zomxholo wabo. Umzekelo, ukwenza uluhlu lobungakanani obusisigxina kunye neekopi ezininzi zento enye, indlela yeekopi zeklasi yoQokelelo ingasetyenziswa. Xa usebenza nge-arrays, i-Arrays.asList () iza ngokufanelekileyo. Kubasebenzisi abajonge ukonyusa iimpawu zeJava 8, i-Stream API ibonelela nge-syntax ecacileyo yokuhambisa imisebenzi yoluhlu. Njengamaxesha onke, ukukhetha indlela efanelekileyo kuxhomekeke kakhulu kwiimfuno ezithile kunye nezithintelo zeprojekthi.