C++ Program to Calculate Sum of Natural Numbers

# C++ Program to Calculate Sum of Natural Numbers

#### In this example, you'll learn to calculate the sum of natural numbers.

To understand this example, you should have the knowledge of the following C++ programming topics:

Positive integers 1, 2, 3, 4... are known as natural numbers.

This program takes a positive integer from user( suppose user entered n ) then, this program displays the value of 1+2+3+....+n.

## Example: Sum of Natural Numbers using loop

``````#include <iostream>
using namespace std;

int main()
{
int n, sum = 0;

cout << "Enter a positive integer: ";
cin >> n;

for (int i = 1; i <= n; ++i) {
sum += i;
}

cout << "Sum = " << sum;
return 0;
}``````

Output

```Enter a positive integer: 50
Sum = 1275```

This program assumes that user always enters positive number.

If user enters negative number, Sum = 0 is displayed and program is terminated.

This program can also be done using recursion. Check out this article for calculating sum of natural numbers using recursion.