Reverse a Number using do while in C language

This C program reverses the digits of a given number using a do-while loop. The process involves repeatedly extracting the last digit of the number and constructing the reversed number by appending this digit to a new number.

How it works:

1. The program takes an integer input from the user.
2. A do-while loop is used to reverse the number:
3. In each iteration, the last digit of the number is extracted using the modulus operator (number % 10).
4. This digit is added to the reversed number by multiplying the current reversed number by 10 (shifting its digits to the left) and then adding the extracted digit.
5. The number is then divided by 10 (removing the last digit) using integer division (number / 10).
6. The loop continues until the number becomes zero.
7. After the loop finishes, the reversed number is printed.

#include <stdio.h>

int main() {
    int num, rev = 0;

    printf("Enter a number: ");
    scanf("%d", &num);

    do {
        rev = rev * 10 + num % 10;
        num = num / 10;
    } while (num != 0);

    printf("Reversed number = %d\n", rev);

    return 0;
}

Output - 

Enter a number: 123
Reversed number = 321