valarray sum() in C++

The sum() function is defined in valarray header file. This function returns the sum of all the elements in the valarray, as if calculated by applying operator+= to a copy of one element and all the other elements, in an unspecified order.

Syntax:

T sum() const;

Returns: This function returns the sum of all the elements in the valarray.

Below programs illustrate the above function:

Example 1:-

// C++ program to demonstrate
// example of sum() function.

#include <bits/stdc++.h>
using namespace std;

int main()
{

    // Initializing valarray
    valarray<int> varr = { 15, 10, 30, 33, 40 };

    // Displaying sum of valarray
    cout << "The sum of valarray is = "
         << varr.sum() << endl;

    return 0;
}

Output:

The sum of valarray is = 128

Example 2:-

// C++ program to demonstrate
// example of sum() function.

#include <bits/stdc++.h>
using namespace std;

int main()
{

    // Initializing valarray
    valarray<int> varr = { 1, 2, 3, 4, 5 };

    // Displaying sum of valarray
    cout << "The sum of valarray is = "
         << varr.sum() << endl;

    return 0;
}

Output:

The sum of valarray is = 15