C Program to Print Multiples of 5 using do while loop


This article focuses on a C program to print multiples of 5 using the do-while loop, providing step-by-step explanations and examples to help you understand the concept better.

In the world of programming, loops are an essential construct that allows repetitive execution of a block of code.

One such loop is the do-while loop, which ensures that the code is executed at least once before checking the condition for further execution.

Also Read: Factorial of a Number using Command Line Arguments in Java

How Does the Do-While Loop Work?

The do-while loop in C works by executing a block of code and then checking the loop condition.

If the condition evaluates to true, the code block is executed again. This process continues until the condition evaluates to false.

Syntax of the Do-While Loop

The syntax of the do-while loop in C is as follows:

do {
   // Code block
} while (condition);

The code block is executed first, and then the condition is checked. If the condition is true, the loop continues.

Otherwise, the loop terminates, and the program proceeds to the next statement after the loop.

Also Read: Java Program to Find Whether a Person is Eligible to Vote or Not

C Program: Print Multiples of 5 Using Do While Loop

Now, let’s dive into the C program that prints multiples of 5 using the do-while loop. Here’s the code:

#include <stdio.h>

int main() {
   int num = 1;

   do {
      if (num % 5 == 0) {
         printf("%d ", num);
   } while (num <= 100);

   return 0;

Explanation of the Program

  1. We start by including the necessary header file, stdio.h, which allows us to use the printf function to print the multiples of 5.
  2. Inside the main function, we declare an integer variable num and initialize it to 1. This variable will keep track of the numbers we want to check for multiples of 5.
  3. The do-while loop begins. Inside the loop, we check if num is divisible by 5 using the modulo operator (%). If the remainder is 0, it means num is a multiple of 5, so we print it using the printf function.
  4. After printing the number, we increment num by 1.
  5. The condition num <= 100 is checked at the end of each iteration. If it evaluates to true, the loop continues, and the process repeats. If it evaluates to false, the loop terminates, and the program exits.
  6. Finally, the main function returns 0, indicating successful program execution.

Output of the Program

When you run the program, it will print the multiples of 5 between 1 and 100, inclusive:

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Also Read: Unveiling Looping Constructs: Exploring the Do-While Loop

Frequently Asked Questions (FAQs)

Q1: What is the purpose of using a do-while loop in this program?

The do-while loop ensures that the code block is executed at least once, regardless of the initial condition. In this program, it allows us to print the first multiple of 5, which is 5 itself.

Q2: Can we achieve the same result using a different loop, like the while loop?

Yes, we can achieve the same result using a while loop. However, in that case, we would need to initialize the variable num to 5 before entering the loop. The do-while loop simplifies the program by allowing us to start with num = 1.

Q3: How can I modify the program to print multiples of a different number?

To print multiples of a different number, you need to modify the condition inside the if statement. For example, to print multiples of 3, you would use the condition num % 3 == 0.

Q4: What happens if we remove the num++ statement from the program?

If we remove the num++ statement, the program would enter an infinite loop because the value of num would never change. It is essential to increment num to avoid infinite looping.

Q5: Can the program print multiples of 5 in reverse order, from 100 to 5?

Yes, we can modify the program to print multiples of 5 in reverse order. To do this, we can start with num = 100 and decrement num by 1 inside the loop.

Q6: How can I modify the program to print a specific number of multiples?

To print a specific number of multiples, you can introduce a counter variable and terminate the loop when the counter reaches the desired number. For example, if you want to print the first 10 multiples, you can introduce a counter variable and set the condition to counter <= 10.

Also Read: Boost Python Code Efficiency: Eliminating Loops for Enhanced Performance


The C program to print multiples of 5 using the do-while loop demonstrates the fundamental concept of loops and conditional statements.

By understanding the structure and syntax of the do-while loop, you can easily adapt it to solve various programming problems.

Remember to keep the loop condition in mind to avoid infinite loops and ensure your program executes efficiently.