java - 反数是怎么得来的？

Question

我不明白使用这行代码的含义

这是在 while block 上。

import java.util.Scanner;

public class ReverseNumberWhile {
    public static void main(String[] args){

       int num = 0;
       int reversenum = 0;

       System.out.println("Enter your number and press enter: ");

       Scanner input = new Scanner(System.in);
       num = input.nextInt();

       while(num != 0) {
           reversenum = reversenum * 10;
           reversenum = reversenum + num%10;
           num = num/10;
       }

       System.out.println("Reverse of input number is: " + reversenum);
   } 
}

Answer 1

就这样，评论:

 while(num != 0)
       {
           reversenum = reversenum * 10; //This moves the reversenum attained in previous iteration to one higher place value
           reversenum = reversenum + num%10; // num%10 gives you the last digit which is added to the existing reversenum
           num = num/10; //This leaves the remaining digits removing rightmost
       }