C Program to Demonstrate the Use of Loops

 

Introduction

Loops are a fundamental concept in programming that allow us to execute a block of code repeatedly. In this blog, we'll explore how to use loops in C with a simple example that calculates the sum of the first n natural numbers. This demonstration will help you understand the basics of for, while, and do-while loops.

Step-by-Step Guide

1. Understand the Problem: The task is to calculate the sum of the first n natural numbers, where n is provided by the user.

2. Logic: We will use loops to repeatedly add numbers from 1 to n and display the total sum.

C Program Code

#include <stdio.h>

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

    // Prompting user for input
    printf("Enter a positive integer: ");
    scanf("%d", &n);

    // Using a for loop to calculate the sum
    for (int i = 1; i <= n; i++) {
        sum += i;
    }

    // Displaying the result
    printf("The sum of the first %d natural numbers is: %d\n", n, sum);

    return 0;
}

Explanation of the Code

1. Input: The program prompts the user to enter a positive integer n.

2. Loop: A for loop is used to iterate from 1 to n. In each iteration, the loop adds the current value of i to the sum.

3. Output: After the loop completes, the program displays the total sum.

Example Output

Enter a positive integer: 5
The sum of the first 5 natural numbers is: 15

Variations

1. Using a while Loop:

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

2. Using a do-while Loop:

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

Conclusion

Loops are incredibly versatile and widely used in programming. This example shows how to use them for a simple task, but the possibilities are endless. Mastering loops will make your programs more efficient and powerful.