package lambdasinaction.chap5; import lambdasinaction.chap4.*; import java.util.stream.*; import java.util.*; import static lambdasinaction.chap4.Dish.menu; public class Reducing{ public static void main(String...args){ List<Integer> numbers = Arrays.asList(3,4,5,1,2); int sum = numbers.stream().reduce(0, (a, b) -> a + b); System.out.println(sum); int sum2 = numbers.stream().reduce(0, Integer::sum); System.out.println(sum2); int max = numbers.stream().reduce(0, (a, b) -> Integer.max(a, b)); System.out.println(max); Optional<Integer> min = numbers.stream().reduce(Integer::min); min.ifPresent(System.out::println); int calories = menu.stream() .map(Dish::getCalories) .reduce(0, Integer::sum); System.out.println("Number of calories:" + calories); } }