Example: Reverse Number using Recursion in Java

// Reverse Number using Recursion
public class Main {

    // Helper function to reverse the number
    public static int reverseNumberRecursive(int num, int reversedNum) {
        // Base case: if the number becomes 0, return the reversed number
        if (num == 0) {
            return reversedNum;
        }

        // Extract the last digit
        int lastDigit = num % 10;

        // Append the last digit to the reversed number
        reversedNum = (reversedNum * 10) + lastDigit;

        // Recursively call with the remaining number (without the last digit)
        return reverseNumberRecursive(num / 10, reversedNum);
    }

    public static void main(String[] args) {
        // Step 1: Define the number to be reversed
        int number = 12345;
        System.out.println("Original Number: " + number);

        // Step 2: Call the recursive function to reverse the number
        int reversed = reverseNumberRecursive(number, 0);

        // Step 3: Print the reversed number
        System.out.println("Reversed Number (Recursive): " + reversed);
    }
}