How to Reverse a Number in Java

Hey there! I'm Kunal Gavhane, and I am a software engineer. I love tinkering with code and solving puzzles. Today, I'm excited to share with you a fun topic in Java programming. We'll be exploring how to reverse numbers, and I'll guide you through it step by step.

So, let's dive in together and learn something new!

Introduction:

In this guide, we'll learn how to reverse a number using Java programming language. Reversing a number means flipping its digits, for example, turning 123 into 321.

Steps to Reverse a Number:

1. Get the Number: First, we need to take the number as input from the user. We'll use a variable to store this number.

2. Initialize Variables: We'll use variables to store the original number, the reversed number, and temporary values during the reversal process.

3. Reverse the Number: To reverse the number, we'll use a loop. Inside the loop, we'll extract the last digit of the original number using the modulo operator (%) and add it to the reversed number. Then, we'll remove the last digit from the original number by dividing it by 10. We'll repeat this process until the original number becomes 0.

4. Display the Reversed Number: Once the reversal is complete, we'll display the reversed number to the user.

Here's the code in Java:

import java.util.Scanner;

public class ReverseNumber {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter a number to reverse: ");
        int number = scanner.nextInt();

        int reversedNumber = 0;
        int remainder;

        while(number != 0) {
            remainder = number % 10;
            reversedNumber = reversedNumber * 10 + remainder;
            number /= 10;
        }

        System.out.println("Reversed Number: " + reversedNumber);
    }
}

Explanation:

• We use a Scanner object to take user input.

• Inside the while loop, we repeatedly extract the last digit of the original number, add it to the reversed number, and then remove the last digit from the original number.

• The loop continues until the original number becomes 0.

• Finally, we display the reversed number to the user.

By following these steps and understanding the provided Java code, you can easily reverse any number in your Java programs. It's a useful skill that comes in handy in various programming scenarios.