Program to find sum of elements in a given array

Last Updated : 20 Sep, 2024

Given an array of integers, find the sum of its elements.

Examples:

Input : arr[] = {1, 2, 3}
Output : 6
Explanation: 1 + 2 + 3 = 6
Input : arr[] = {15, 12, 13, 10}
Output : 50

Sum of elements of an array using Recursion:

The idea is to use recursive approach which calculates the sum of an array by breaking it down into two cases: the base case, where if the array is empty the sum is 0; and the recursive case, where the sum is calculated by adding the first element to the sum of the remaining elements which is computed through a recursive call with the array shifted by one position and size reduced by one.

Below is the implementation of the above approach:

C++

/* C++ Program to find sum of elements in a given array using recursion */ #include <iostream> using namespace std; // function to return sum of elements // in an array of size n int sum(int arr[], int n) {  // base case  if (n == 0) {  return 0;  }  else {  // recursively calling the function  return arr[0] + sum(arr + 1, n - 1);  } } int main() {  int arr[] = { 12, 3, 4, 15 };  int n = sizeof(arr) / sizeof(arr[0]);  cout << sum(arr, n);  return 0;   }

/* C++ Program to find sum of elements in a given array using recursion */ #include <stdio.h> #include <stdlib.h> #include <string.h> // function to return sum of elements // in an array of size n int sum(int arr[], int n) {  // base case  if (n == 0) {  return 0;  }  else {  // recursively calling the function  return arr[0] + sum(arr + 1, n - 1);  } } int main() {  int arr[] = { 12, 3, 4, 15 };  int n = sizeof(arr) / sizeof(arr[0]);  printf("%d", sum(arr, n));  return 0; }

Java

/*package whatever //do not write package name here */ import java.io.*; class GFG {  static int sum(int[] arr, int n)  {  // base or terminating condition  if (n <= 0) {  return 0;  }  // Calling method recursively  return sum(arr, n - 1) + arr[n - 1];  }  public static void main(String[] args)  {  int arr[] = { 12, 3, 4, 15 };  int s = sum(arr, arr.length);  System.out.println(s);  } }

Python

# python Program to find sum of elements # in a given array using recursion # function to return sum of elements # in an array of size n def sum1(arr): if len(arr) == 1: return arr[0] else: return arr[0] + sum1(arr[1:]) arr = [12, 3, 4, 15] print(sum1(arr)) # This code is contributed by laxmigangarajula03

using System; public class GFG {  static int sum(int[] arr, int n)  {  // base or terminating condition  if (n <= 0) {  return 0;  }  // Calling method recursively  return sum(arr, n - 1) + arr[n - 1];  }  public static void Main()  {  int[] arr = { 12, 3, 4, 15 };  int s = sum(arr, arr.Length);  Console.Write(s);  } } // This code is contributed by ksrikanth0498.

JavaScript

function sum(let arr, let n)  {  // base or terminating condition  if (n <= 0) {  return 0;  }  // Calling method recursively  return sum(arr, n-1 ) + arr[n-1];  }  let arr = {12, 3, 4, 15};  let s = sum(arr, arr.length);  document.write(s);

Output

Time Complexity: O(n)
Auxiliary Space: O(n), Recursive stack space

Sum of elements of an array using Iteration:

The idea is to iterate through each element of the array and adding it to a variable called sum. The sum variable is initialized to 0 before the iteration starts. After the iteration, the final sum is returned.

Below is the implementation of the above approach:

/* C Program to find sum of elements  in a given array */ #include <bits/stdc++.h> // function to return sum of elements // in an array of size n int sum(int arr[], int n) {  int sum = 0; // initialize sum  // Iterate through all elements  // and add them to sum  for (int i = 0; i < n; i++)  sum += arr[i];  return sum; } int main() {  int arr[] = { 12, 3, 4, 15 };  int n = sizeof(arr) / sizeof(arr[0]);  printf("Sum of given array is %d", sum(arr, n));  return 0; }

C++

/* C++ Program to find sum of elements in a given array */ #include <bits/stdc++.h> using namespace std; // function to return sum of elements // in an array of size n int sum(int arr[], int n) {  int sum = 0; // initialize sum  // Iterate through all elements  // and add them to sum  for (int i = 0; i < n; i++)  sum += arr[i];  return sum; } // Driver code int main() {  int arr[] = { 12, 3, 4, 15 };  int n = sizeof(arr) / sizeof(arr[0]);  cout << "Sum of given array is " << sum(arr, n);  return 0; } // This code is contributed by rathbhupendra

Java

/* Java Program to find sum of elements in a given array */ class Test {  static int arr[] = { 12, 3, 4, 15 };  // method for sum of elements in an array  static int sum()  {  int sum = 0; // initialize sum  int i;  // Iterate through all elements and add them to sum  for (i = 0; i < arr.length; i++)  sum += arr[i];  return sum;  }  // Driver method  public static void main(String[] args)  {  System.out.println("Sum of given array is "  + sum());  } }

Python

# Function to return sum of  # elements in an array def sum_array(arr): total = 0 # initialize sum # Iterate through all elements # and add them to total for num in arr: total += num return total # Driver code arr = [12, 3, 4, 15] print("Sum of given array is", sum_array(arr))

// C# Program to find sum of elements in a // given array using System; class GFG {  // method for sum of elements in an array  static int sum(int[] arr, int n)  {  int sum = 0; // initialize sum  // Iterate through all elements and  // add them to sum  for (int i = 0; i < n; i++)  sum += arr[i];  return sum;  }  // Driver method  public static void Main()  {  int[] arr = { 12, 3, 4, 15 };  int n = arr.Length;  Console.Write("Sum of given array is "  + sum(arr, n));  } } // This code is contributed by Sam007.

JavaScript

//JavaScript Program to find  //sum of elements in a given array   // function to return sum of elements   // in an array of size n   function sum(arr) {   let sum = 0; // initialize sum     // Iterate through all elements   // and add them to sum   for (let i = 0; i < arr.length; i++)   sum += arr[i];     return sum;   }     // Driver code   let arr = [12, 3, 4, 15];  console.log("Sum of given array is " + sum(arr));    // This code is contributed by Surbhi Tyagi

PHP

<?php // PHP Program to find sum of  // elements in a given array  // function to return sum  // of elements in an array // of size n function sum( $arr, $n) { // initialize sum $sum = 0; // Iterate through all elements  // and add them to sum for ($i = 0; $i < $n; $i++) $sum += $arr[$i]; return $sum; } // Driver Code $arr =array(12, 3, 4, 15); $n = sizeof($arr); echo "Sum of given array is ", sum($arr, $n); // This code is contributed by aj_36 ?>

Output

Sum of given array is 34

Time Complexity: O(n)
Auxiliary Space: O(1)

Sum of elements of an array using Inbuild Methods:

The idea is to make use of built-in functions to find the sum of elements in a given array. These functions eliminate the need for explicit iteration, enhancing code simplicity.

Below is the implementation of above approach:

C++

/* C++ Program to find sum of elements in a given array */ #include <bits/stdc++.h> using namespace std; // Driver code int main() {  int arr[] = { 12, 3, 4, 15 };  int n = sizeof(arr) / sizeof(arr[0]);  // calling accumulate function, passing first, last  // element and  // initial sum, which is 0 in this case.  cout << "Sum of given array is "  << accumulate(arr, arr + n, 0);  return 0; } // This code is contributed by pranoy_coder

Java

import java.util.Arrays; public class GFG {  // Driver code  public static void main(String[] args) {  int[] arr = {12, 3, 4, 15};  int sum = Arrays.stream(arr).sum();  System.out.println("Sum of given array is " + sum);  } }

Python

# Python3 program to find sum of elements # in a given array # Driver code if __name__ == "__main__": arr = [12, 3, 4, 15] n = len(arr) # Calling accumulate function, passing # first, last element and initial sum, # which is 0 in this case. print("Sum of given array is ", sum(arr)) # This code is contributed by ukasp

// C# Program to find sum of elements in a // given array using System; using System.Linq; class GFG {  // Driver method  public static void Main()  {  int[] arr = { 12, 3, 4, 15 };  int n = arr.Length;  // calling LINQ Sum method on the array  // to calculate the sum of elements in an array  int sum = arr.Sum();  Console.Write("Sum of given array is " + sum);  } } // This code is contributed by abhishekmaran_.

JavaScript

// JavaScript program to find the sum of elements // in a given array // Driver code const arr = [12, 3, 4, 15]; const n = arr.length; // Calling the built-in reduce function to calculate the sum of elements in the array. const sumOfArray = arr.reduce((accumulator, currentValue) => accumulator + currentValue, 0); console.log("Sum of given array is ", sumOfArray); // This code is contributed by Yash Agarwal(yashagarwal2852002)