Python Program to Find Sum of First n Natural Numbers Using While Loop

In this tutorial, we are going to write a program to find the sum of the first n natural numbers using a while loop.

In mathematics, the sum of the first n natural numbers is given by the formula n(n+1)/2.

So, this is a Python program to find the sum of the first n natural numbers using a while loop.

Simple Code:

n = int(input("Enter a number: "))
sum = 0
i = 1
while i <= n:
    sum += i
    i += 1
print("The sum of first", n, "natural numbers is:", sum)

Output:

Code With Explanation:

# Take input of the number
n = int(input("Enter a number: "))
# Set initial sum to 0 and initial number to 1
sum = 0
i = 1
# Loop until i is less than or equal to n
while i <= n:
    # Add i to the sum
    sum += i
    # Increment i by 1
    i += 1
# Print the sum of the first n natural numbers
print("The sum of first", n, "natural numbers is:", sum)

Explanation:

The program takes an input of a number and uses a while loop to find the sum of the first n natural numbers.

The loop continues until i becomes greater than n.

In each iteration, the current value of i is added to the sum of natural numbers, and then i is incremented by 1.

Finally, the program prints the sum of the first n natural numbers.