Java nodrošina jaunu metodi forEach() elementu atkārtošanai. Tas ir definēts interfeisā Iterable un Stream. Tā ir noklusējuma metode, kas definēta saskarnē Iterable. Kolekciju klases, kas paplašina Iterable saskarni, var izmantot forEach cilpu, lai iterētu elementus.
Šī metode izmanto vienu parametru, kas ir funkcionāls interfeiss. Tātad, jūs varat nodot lambda izteiksmi kā argumentu.
forEach() paraksts iterējamā interfeisā
default void forEach(Consumeraction)
Java 8 forEach() 1. piemērs
import java.util.ArrayList; import java.util.List; public class ForEachExample { public static void main(String[] args) { List gamesList = new ArrayList(); gamesList.add('Football'); gamesList.add('Cricket'); gamesList.add('Chess'); gamesList.add('Hocky'); System.out.println('------------Iterating by passing lambda expression--------------'); gamesList.forEach(games -> System.out.println(games)); } } Izvade:
------------Iterating by passing lambda expression-------------- Football Cricket Chess Hocky
Java 8 forEach() 2. piemērs
import java.util.ArrayList; import java.util.List; public class ForEachExample { public static void main(String[] args) { List gamesList = new ArrayList(); gamesList.add('Football'); gamesList.add('Cricket'); gamesList.add('Chess'); gamesList.add('Hocky'); System.out.println('------------Iterating by passing method reference---------------'); gamesList.forEach(System.out::println); } } Izvade:
------------Iterating by passing method reference--------------- Football Cricket Chess Hocky
Java straume forEachOrdered() metodei
Kopā ar metodi forEach() Java nodrošina vēl vienu metodi forEachOrdered(). To izmanto, lai iterētu elementus straumes norādītajā secībā.
Sindaba:
void forEachOrdered(Consumer action)
Java Stream forEachOrdered() metodes piemērs
import java.util.ArrayList; import java.util.List; public class ForEachOrderedExample { public static void main(String[] args) { List gamesList = new ArrayList(); gamesList.add('Football'); gamesList.add('Cricket'); gamesList.add('Chess'); gamesList.add('Hocky'); System.out.println('------------Iterating by passing lambda expression---------------'); gamesList.stream().forEachOrdered(games -> System.out.println(games)); System.out.println('------------Iterating by passing method reference---------------'); gamesList.stream().forEachOrdered(System.out::println); } } Izvade:
------------Iterating by passing lambda expression--------------- Football Cricket Chess Hocky ------------Iterating by passing method reference--------------- Football Cricket Chess Hocky