Reducing.java

package com.lun.c05;

import java.util.stream.*;

import com.lun.c04.Dish;

import java.util.*;

import static com.lun.c04.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);
	}
}