How to display a number with the reverse order of digits?

Question

Java

Write a method that takes a positive integer as a parameter and returns a number with the opposite digit order. For example, for parameter 123 the method will return 321, for parameter 120 the method will return 21.
I wrote a code that displays the reciprocal of the number, but of course I can’t perform operations with it ... What needs to be corrected in the code in order to complete the task correctly? (Yes , I know that the method does not return anything, but only such an option comes to my mind)

import java.util.*;
class Practice2{
  static Scanner eva = new Scanner(System.in);
  public static void main(String[] args) {
    int x,y;
    x = eva.nextInt();
    what(x);
    
  }
  static void what(int a) {
    int b;
    while(a>0) {
      b = a%10;
      a/=10;
      System.out.print(b+"");
    }
    
  }
  
}

Answer 1

static int what(int a) {
        int result = 0;

        while (a > 0) {
            result = result * 10 + a % 10;
            a = a / 10;
        }

        return result;
    }

*corrected version