C++ Program to Calculate Sum of Natural Numbers (In 5 lines of code)

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

To understand this Program to Calculate Sum of Natural Numbers, you should have the knowledge of following C++ programming topics:

C++ for Loop

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

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

Program to find Sum of Natural Number 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 the positive number.

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

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

Related Program

Ask your questions and clarify your/others doubts on Sum of Natural Number by commenting. Documentation