sum up Arraylist via java stream in java 8

Sum up ArrayList via Java Stream in Java 8

This article will help you to understand How to Sum up ArrayList via Java Stream in Java 8.

Java Program of Sum up ArrayList via Java Stream in Java 8


package com.codenuclear.lamda;

import java.util.Arrays;
import java.util.List;

public class LambdaExample2 {

	public static void main(String[] args) {
		List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);

		System.out.print(sumAll(numbers));

		int total = numbers.stream().mapToInt(i -> i.intValue()).sum();
		System.out.print(total);

		total = numbers.stream().mapToInt(value -> value).sum();
		System.out.print(total);

		total = numbers.stream().mapToInt(Integer::intValue).sum();
		System.out.print(total);

	}

	public static int sumAll(List<Integer> numbers) {
		int total = 0;
		for (int number : numbers) {
			total += number;
		}
		return total;
	}

}