The reverse of a given number is simply called as when the number is **123**, the reverse number should be **321**. In java, there are multiple ways to calculate the reverse of a given number. Here we will discuss a simple way using a** while loop**.

Follow the below steps to calculate the reverse of a number,

- First find the last digit of given number (calculating the remainder by dividing the number by 10).
- Now multiply the variable reverse by 10 and add the calculated remainder of previous step.
- Remove the last digit from the number by dividing the number by 10.
- Repeat the above 3 steps inside
**while loop**until the number become 0.

Letโs see the complete logic to calculate the reverse of a given number,

### Solution

*ReverseNumber.java*

```
package com.javacodepoint.programs;
import java.util.Scanner;
public class ReverseNumber {
public static void main(String[] args) {
// Taking input from the user to reverse
System.out.print("Enter an integer number:");
// Reading user input using Scanner object
int number = new Scanner(System.in).nextInt();
//Initiating reverse variable with 0
int reverse = 0;
int tempNumber = number;
// while loop will continue until the number become 0
while(number > 0) {
//Finding the last digit of the number
int remainder = number % 10;
//Calculating the reverse by multiplying it with 10 and adding remainder (last digit)
reverse = reverse * 10 + remainder;
//Removing the last digit from the number
number = number / 10;
}
System.out.print("The reverse of the given number is = "+reverse);
}
}
```

**OUTPUT:**

Enter an integer number: 12345

The reverse of the given number is = 54321