Java Program to Find the Sum of Elements in an Array

Introduction

Finding the sum of all elements in an array is a basic operation that is commonly used in various programming tasks. This guide will walk you through writing a Java program that calculates the sum of the elements in a given array.

Problem Statement

Create a Java program that:

Prompts the user to enter the size of an array and its elements.
Calculates the sum of all the elements in the array.
Displays the sum.

Example:

Input: [1, 2, 3, 4, 5]
Output: "Sum of elements: 15"

Solution Steps

Read the Array Size and Elements: Use the Scanner class to take the size and elements of the array as input from the user.
Initialize a Sum Variable: Initialize a variable to store the sum of the elements.
Traverse the Array: Use a loop to iterate through the array and accumulate the sum of its elements.
Display the Result: Print the sum of the elements.

Java Program

// Java Program to Find the Sum of Elements in an Array
// Author: https://www.rameshfadatare.com/

import java.util.Scanner;

public class SumOfArrayElements {
    public static void main(String[] args) {
        // Step 1: Read the size and elements of the array from the user
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter the size of the array: ");
        int size = scanner.nextInt();
        
        int[] array = new int[size];
        
        System.out.println("Enter the elements of the array:");
        for (int i = 0; i < size; i++) {
            array[i] = scanner.nextInt();
        }
        
        // Step 2: Initialize sum variable
        int sum = 0;
        
        // Step 3: Traverse the array and calculate the sum
        for (int i = 0; i < size; i++) {
            sum += array[i];
        }
        
        // Step 4: Display the sum of elements
        System.out.println("Sum of elements: " + sum);
    }
}

Explanation

Step 1: Read the Array Size and Elements

The Scanner class is used to read the size of the array and its elements. The nextInt() method captures the size and each element.

Step 2: Initialize a Sum Variable

A variable sum is initialized to 0. This variable will be used to accumulate the sum of the array elements.

Step 3: Traverse the Array

A for loop is used to iterate through each element of the array.
During each iteration, the value of the current element is added to sum.

Step 4: Display the Result

The program prints the total sum of the elements using System.out.println().

Output Example

Example 1:

Enter the size of the array: 5
Enter the elements of the array:
1 2 3 4 5
Sum of elements: 15

Example 2:

Enter the size of the array: 3
Enter the elements of the array:
10 20 30
Sum of elements: 60

Example 3:

Enter the size of the array: 6
Enter the elements of the array:
5 10 15 20 25 30
Sum of elements: 105

Conclusion

This Java program demonstrates how to calculate the sum of elements in an array. It covers basic concepts such as loops, array traversal, and arithmetic operations, making it a valuable exercise for beginners learning Java programming.