# Sum of consecutive two elements in a array

• Difficulty Level : Basic
• Last Updated : 18 Aug, 2021

Given an array print sum of the pairwise consecutive elements.

Examples:

```Input  : 8, 5, 4, 3, 15, 20
Output : 13, 9, 7, 18, 35

Input  : 5, 10, 15, 20
Output : 15, 25, 35 ```

The solution is to traverse the array and saving the sum of consecutive numbers in the variable sum.

## C++

 `// C++ program to print the``// sum of the consecutive elements.``#include ``#include ` `// Function to print pairwise sum``void` `pairwiseSum(``int` `arr[], ``int` `n)``{``    ``int` `sum = 0;  ``    ``for` `(``int` `i = 0; i < n - 1; i++)``    ``{``        ``// adding the alternate numbers``        ``sum = arr[i] + arr[i + 1];``        ``printf``(``" %d "``, sum);``    ``}``}` `// Driver function to test function``int` `main()``{``    ``int` `arr[] = {4, 10, 15, 5, 6};``    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr[0]);``    ` `    ``pairwiseSum(arr, n);``    ``return` `0;``}`

## Java

 `// Java program to print the``// sum of the consecutive elements.` `class` `Arraysum {``    ` `    ``// Function to print Alternatesum``    ``static` `void` `pairwiseSum(``int` `arr[], ``int` `n)``    ``{``        ``int` `sum = ``0``;``        ``for` `(``int` `i = ``0``; i + ``1` `< n; i++)``        ``{``            ``// adding the alternate numbers``            ``sum = arr[i] + arr[i + ``1``];``            ``System.out.print(sum + ``" "``);``        ``}``    ``}``    ` `    ``/*driver function to test function*/``    ``public` `static` `void` `main(String[] args)``    ``{``    ` `        ``int` `arr[] = {``4``, ``10``, ``15``, ``5``, ``6``};``        ``int` `n = arr.length;``        ``pairwiseSum(arr, n);``    ``}``}`

## Python3

 `# Python3 program to print the``# sum of the consecutive elements.` `# Function to print alternate sum``def` `pairwiseSum(lst, n):``    ``sum` `=` `0``;``    ``for` `i ``in` `range``(``len``(lst)``-``1``):``        ` `        ``# adding the alternate numbers``        ``sum` `=` `lst[i] ``+` `lst[i ``+` `1``]``        ``print` `(``sum``, end ``=` `" "``)``    ` `# driver function to test function``arr ``=``[``4``, ``10``, ``15``, ``5``, ``6``]``size ``=` `len``(arr)``pairwiseSum(arr, size)`

## C#

 `// C# program to print the``// sum of the consecutive elements.``using` `System;` `class` `Arraysum {``    ` `    ``// Function to print Alternatesum``    ``static` `void` `pairwiseSum(``int` `[]arr, ``int` `n)``    ``{``        ``int` `sum = 0;``        ``for` `(``int` `i = 0; i + 1 < n; i++)``        ``{``            ``// adding the alternate numbers``            ``sum = arr[i] + arr[i + 1];``            ``Console.Write(sum + ``" "``);``        ``}``    ``}``    ` `    ``// Driver function``    ``public` `static` `void` `Main()``    ``{``    ` `        ``int` `[]arr = {4, 10, 15, 5, 6};``        ``int` `n = arr.Length;``        ``pairwiseSum(arr, n);``    ``}``}` `// This code is contributed by vt_m.`

## PHP

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## Javascript

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Output:

`14 25 20 11`

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