package functionalexamples; import java.util.List; import java.util.Optional; import java.util.Set; public class FindFirstExample { public static void main(String[] args) { List numbersList = List.of(5,1022,23,324,61,2); System.out.println("List elements " + numbersList); Optional element = numbersList.stream() .filter(n -> n%2 == 0) .findFirst(); System.out.println("From list : " +element.orElseThrow()); Set numbersSet = Set.of(5,1022,23,324,62,2); System.out.println("Set elements " + numbersSet); Optional elementSet = numbersSet.stream() .sorted() .filter(n -> n%2 == 0) .findFirst(); System.out.println("From set : " +elementSet.orElseThrow()); } }