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

• Difficulty Level : Easy
• Last Updated : 13 Sep, 2022

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 ```
Recommended Practice

Implementation:

## C++

 `// CPP program to find out``// Sum of elements at even and``// odd index positions separately``#include ``  ` `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);``    ``}``}`

## 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 ``=` `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

 ``

## Javascript

 ``

Output

```Even index positions sum 9
Odd index positions sum 12```

Time Complexity: O(length(arr))
Auxiliary Space: 0(1)

#### 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:

## C++

 `#include ``using` `namespace` `std;` `// Function to calculate sum``int` `EvenOddSum(``int` `arr[] , ``int` `n)``{``  ``int` `even = 0;``  ``int` `odd = 0;` `  ``// Loop to find even, odd sum``  ``for` `(``int` `i = 0; i < n; i++) {``    ``if` `(i % 2 == 0)``      ``even += arr[i];``    ``else``      ``odd += arr[i];``  ``}``  ``cout<<``"Even index positions sum "``<

## Java

 `// Java program to find out sum of elements at even``// and odd index positions separately` `import` `java.io.*;` `class` `GFG {` `    ``// Function to calculate sum``    ``static` `void` `EvenOddSum(``int``[] arr, ``int` `n)``    ``{``        ``int` `even = ``0``;``        ``int` `odd = ``0``;` `        ``// Loop to find even, odd sum``        ``for` `(``int` `i = ``0``; i < n; i++) {``            ``if` `(i % ``2` `== ``0``)``                ``even += arr[i];``            ``else``                ``odd += arr[i];``        ``}``        ``System.out.println(``"Even index positions sum "``                           ``+ even);``        ``System.out.print(``"Odd index positions sum "` `+ odd);``    ``}` `    ``public` `static` `void` `main(String[] args)``    ``{``        ``int``[] arr = { ``1``, ``2``, ``3``, ``4``, ``5``, ``6` `};``        ``int` `n = arr.length;` `        ``EvenOddSum(arr, n);``    ``}``}` `// This code is contributed by lokeshmvs21.`

## 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`

## C#

 `// C# program to find out sum of elements at even``// and odd index positions separately``using` `System;` `public` `class` `GFG {` `    ``// Function to calculate sum``    ``static` `void` `EvenOddSum(``int``[] arr, ``int` `n)``    ``{``        ``int` `even = 0;``        ``int` `odd = 0;` `        ``// Loop to find even, odd sum``        ``for` `(``int` `i = 0; i < n; 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);``    ``}` `    ``static` `public` `void` `Main()``    ``{` `        ``// Code``        ``int``[] arr = { 1, 2, 3, 4, 5, 6 };``        ``int` `n = arr.Length;` `        ``EvenOddSum(arr, n);``    ``}``}` `// This code is contributed by lokeshmvs21.`

## Javascript

 ``

Output

```Even index positions sum 9
Odd index positions sum 12```

Time Complexity: O(n) where n is no of elements in given array
Auxiliary Space: 0(1)

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