sum of array elements java code example

Example 1: sum of all numbers in array java

int[] a = {10,20,30,40,50};
int sum = IntStream.of(a).sum();
System.out.println("The sum is " + sum);

Example 2: sum numbers in array java

public class Exercise2 {
public static void main(String[] args) {      
int my_array[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int sum = 0;

for (int i : my_array)
    sum += i;
System.out.println("The sum is " + sum);
}
}

Example 3: add each element in an array java

import java.util.Arrays;
import java.util.Scanner;
public class SumOfElementsOfAnArray {
   public static void main(String args[]){
      System.out.println("Enter the required size of the array :: ");
      Scanner s = new Scanner(System.in);
      int size = s.nextInt();
      int myArray[] = new int [size];
      int sum = 0;
      System.out.println("Enter the elements of the array one by one ");

      for(int i=0; i<size; i++){
         myArray[i] = s.nextInt();
         sum = sum + myArray[i];
      }
      System.out.println("Elements of the array are: "+Arrays.toString(myArray));
      System.out.println("Sum of the elements of the array ::"+sum);
   }
}

Example 4: java running sum of array

class Solution {
    public int[] runningSum(int[] nums) {
        int[] sol = new int[nums.length];
        sol[0] = nums[0];
        for(int i = 1; i < nums.length; i++) {
            sol[i] = sol[i-1] + nums[i];
        }
        return sol;
    }
}

// Example: runningSum([1,3,6,9]) = [1, 4, 10, 19] = [1, 1+3, 1+3+6, 1+3+6+9]