Метка: Stream

Map<Integer, Integer> map = new HashMap<>();
// Collection.stream() + Stream.forEach()
        map.values().stream()
                .forEach(System.out::println);
map.keySet().stream()
                .forEach(System.out::println);

TreeSet<Integer> set = new TreeSet<>();
set.forEach(integer -> {
            System.out.print(integer + " ");
        });