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# How to find the sum of elements of an Array using STL in C++?

• Last Updated : 19 Mar, 2019

Given an array arr[], find the sum of the elements of this array using STL in C++.

Example:

```Input: arr[] = {1, 45, 54, 71, 76, 12}
Output: 259

Input: arr[] = {1, 7, 5, 4, 6, 12}
Output: 35
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: Sum can be found with the help of accumulate() function provided in STL.

Syntax:

```accumulate(first_index, last_index, initial value of sum);
```

Below is the implementation of the above approach:

 `// C++ program to find the sum``// of Array using accumulate() in STL`` ` `#include ``using` `namespace` `std;`` ` `int` `main()``{``    ``// Get the array``    ``int` `arr[] = { 1, 45, 54, 71, 76, 12 };`` ` `    ``// Compute the sizes``    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr);`` ` `    ``// Print the array``    ``cout << ``"Array: "``;``    ``for` `(``int` `i = 0; i < n; i++)``        ``cout << arr[i] << ``" "``;`` ` `    ``// Find the sum``    ``cout << ``"\nSum = "``         ``<< accumulate(arr, arr + n, 0);``    ``return` `0;``}`
Output:
```Array: 1 45 54 71 76 12
Sum = 259
```
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