This is a simple C++ program to learn to calculate the sum of n natural numbers.
Natural numbers are numbers that include all the whole numbers excluding the number 0.
Natural numbers = { 1, 2, 3, 4, 5…………………..}
In this C++ program, n is the number of natural numbers. So to find the sum of n natural numbers we have to add 1 + 2 + 3 + …….+ n.
For example n = 6
sum = 1 + 2 + 3 + 4 + 5 + 6 = 21
The program takes a positive integer from the user. This value is loaded into the variable ‘n’. A for loop can be used to add n natural numbers.
Syntax offorLoop
Here for our program, the loop will be like this,
for (i = 1; i<= n; i++ )
{
sum +=i;
}
initialize the value of 'i' as 1 and check for the condition 'i<=n'. if the condition is not satisfied then add 'i' with the sum and update the value of the 'sum'. increment the value of 'i' by 1 on each iteration. This process will continue until the condition is true. the final result will be on the variable 'sum'. Print 'sum' and finish the program
Step 1: Call the header file iostream.
Step 2: Use the namespace std.
Step 3: Open the integer type main function; int main().
Step 4: Declare integer variables; n, sum
Step 5: Print a message to enter a positive integer.
Step 6: Read the number into the variable n.
Step 7: using a for loop find the sum of natural numbers upto n
Sum = 1+ 2 + 3 +…..+ n;
Step 8: print sum.
Step 9: Exit.
#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;
}
Enter a positive integer: 8 Sum = 36
