Program to print Sum of even and odd elements in an array

• Difficulty Level : Easy
• Last Updated : 13 Dec, 2021

Prerequisite – Array Basics
Given an array, write a program to find the sum of values of even and odd index positions separately.
Examples:

Input : arr = {1, 2, 3, 4, 5, 6}
Output :Even index positions sum 9
Odd index positions sum 12
Explanation: Here, n = 6 so there will be 3 even
index positions and 3 odd index positions in an array
Even = 1 + 3 + 5 = 9
Odd =  2 + 4 + 6 = 12

Input : arr = {10, 20, 30, 40, 50, 60, 70}
Output : Even index positions sum 160
Odd index positions sum 170
Explanation: Here, n = 7 so there will be 3 odd
index positions and 4 even index positions in an array
Even = 10 + 30 + 50 + 70 = 160
Odd = 20 + 40 + 60 = 120

C++

// CPP program to find out
// Sum of elements at even and
// odd index positions separately
#include <iostream>

using namespace std;

// Function to calculate sum
void EvenOddSum(int arr[], int n)
{
int even = 0;
int odd = 0;
for (int i = 0; i < n; i++) {
// Loop to find even, odd sum
if (i % 2 == 0)
even += arr[i];
else
odd += arr[i];
}

cout << "Even index positions sum " << even;
cout << "\nOdd index positions sum " << odd;
}

// Driver function
int main()
{
int arr[] = { 1, 2, 3, 4, 5, 6 };
int n = sizeof(arr) / sizeof(arr);

EvenOddSum(arr, n);

return 0;
}

Java

// Java program to find out
// Sum of elements at even and
// odd index positions separately
import java.io.*;

class EvenOddSum {
public static void main(String args[])
{
int arr[] = { 1, 2, 3, 4, 5, 6 };
int even = 0, odd = 0;

// Loop to find even, odd sum
for (int i = 0; i < arr.length; i++) {
if (i % 2 == 0)
even += arr[i];
else
odd += arr[i];
}

System.out.println("Even index positions sum: " + even);
System.out.println("Odd index positions sum: " + odd);
}
}

Python

# Python program to find out
# Sum of elements at even and
# odd index positions separately

# Function to calculate Sum
def EvenOddSum(a, n):
even = 0
odd = 0
for i in range(n):

# Loop to find even, odd Sum
if i % 2 == 0:
even += a[i]
else:
odd += a[i]

print "Even index positions sum ", even
print "nOdd index positions sum ", odd

# Driver Function

arr = [1, 2, 3, 4, 5, 6]
n = len(arr)

EvenOddSum(arr, n)

# This code is contributed by Sachin Bisht

C#

// C# program to find out
// Sum of elements at even and
// odd index positions separately
using System;

public class GFG {

public static void Main()
{
int[] arr = { 1, 2, 3, 4, 5, 6 };
int even = 0, odd = 0;

// Loop to find even, odd sum
for (int i = 0; i < arr.Length; i++)
{
if (i % 2 == 0)
even += arr[i];
else
odd += arr[i];
}

Console.WriteLine("Even index positions"
+ " sum: " + even);

Console.WriteLine("Odd index positions "
+ "sum: " + odd);
}
}

// This code is contributed by Sam007.

PHP

<?php
// PHP program to find out
// Sum of elements at even and
// odd index positions separately

// Function to calculate sum
function EvenOddSum(\$arr, \$n)
{
\$even = 0;
\$odd = 0;
for (\$i = 0; \$i < \$n; \$i++)
{

// Loop to find even, odd sum
if (\$i % 2 == 0)
\$even += \$arr[\$i];
else
\$odd += \$arr[\$i];
}

echo("Even index positions sum " . \$even);
echo("\nOdd index positions sum " . \$odd);
}

// Driver Code
\$arr = array( 1, 2, 3, 4, 5, 6 );
\$n = sizeof(\$arr);

EvenOddSum(\$arr, \$n);

// This code is contributed by Ajit.
?>

Javascript

<script>

// Javascript program to find out
// Sum of elements at even and
// odd index positions separately

// Function to calculate sum
function EvenOddSum(arr, n)
{
let even = 0;
let odd = 0;
for (let i = 0; i < n; i++)
{

// Loop to find even, odd sum
if (i % 2 == 0)
even += arr[i];
else
odd += arr[i];
}

document.write("Even index positions sum " + even);
document.write("<br>" + "Odd index positions sum " + odd);
}

// Driver function
let arr = [ 1, 2, 3, 4, 5, 6 ];
let n = arr.length;

EvenOddSum(arr, n);

// This code is contributed by Mayank Tyagi

</script>

Output
Even index positions sum 9
Odd index positions sum 12

Method 2:Using slicing in python:

Calculate sum of all even indices using slicing and repeat the same with odd indices and print sum.

Below is the implementation:

Python3

# Python program to find out
# Sum of elements at even and
# odd index positions separately

# Function to calculate Sum

def EvenOddSum(a, n):
even_sum = sum(a[::2])
odd_sum = sum(a[1::2])
print("Even index positions sum", even_sum)
print("Odd index positions sum", odd_sum)

# Driver Function

arr = [1, 2, 3, 4, 5, 6]
n = len(arr)

EvenOddSum(arr, n)

# This code is contributed by vikkycirus

Javascript

<script>

// Javascript program to find out
// Sum of elements at even and
// odd index positions separately

// Function to calculate sum
function EvenOddSum(arr, n)
{
let even = 0;
let odd = 0;
for (let i = 0; i < n; i++)
{

// Loop to find even, odd sum
if (i % 2 == 0)
even += arr[i];
else
odd += arr[i];
}

document.write("Even index positions sum " + even);
document.write("<br>" + "Odd index positions sum " + odd);
}

// Driver function
let arr = [ 1, 2, 3, 4, 5, 6 ];
let n = arr.length;

EvenOddSum(arr, n);

// This code is contributed by avijitmondal1998.
</script>
Output
Even index positions sum 9
Odd index positions sum 12

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