Reverse a Number in Java - A Quick and Easy Guide

Reverse a Number in Java

In this article, we will learn how to reverse a number in Java. Although the task is quite easy, there are certain subtleties to consider when implementing it.

To reverse a number in Java, we need to use a simple iteration and keep track of the digits present in the number. We can use a while loop to iterate through each digit of the number, one at a time. Then, we can use the modulus operator (%) to find the last digit and append it to a new string or variable. We can also use integer division (/) to remove the last digit from the number at every iteration.

The below Java program shows how to reverse a number.

public class ReverseNumber { 
    public static void main(String[] args) { 
  
        int number = 12345; 
        int reversedNumber = 0; 
        int temp = 0; 
  
        while(number > 0){ 
                  
            // Use modulus operator to strip off the last digit 
            temp = number%10; 
  
            // Create the reversed number 
            reversedNumber = reversedNumber * 10 + temp; 
            number = number/10; 
        } 
  
        System.out.println("Reversed Number: " + reversedNumber); 
    } 
} 

The output of the above program would be Reversed Number: 54321.

We hope that this article helped you understand how to reverse a number in Java. To learn more about Java programming and problem solving, check out our other tutorials!