在没有循环/函数的情况下反向一个数[闭合的]

Question

用户应该输入一个4位数的数字，我需要反向它我导入扫描并收到了来自用户的答案，但是如何反向呢？例如，如果用户键入9876，它将打印6789？我应该用%吗？

import java.util.Scanner;

public class Number {


    public static void main(String[] args) {
        System.out.println("Please enter a 4 digit number:");
        Scanner scanner = new Scanner(System.in);
        int dig = scanner.nextInt();
        if (String.valueOf(dig).length() == 4) ;
        {
            System.out.println("1. Reverse sign.");
            System.out.println("2. Reverse number.");
            System.out.println("3. Reverse sign and number.");
            System.out.println("Please choose an option:");
            int choice = scanner.nextInt();
            if (choice == 1) ;
            {
                dig += -dig + -dig;
                System.out.println(+dig);
            }
            if (choice == 2) ;
            {

            }
        }
    }
}

Answer 1

是的，您可以使用“%”运算符

在示例9876中，您可以

9876 % 10 = 6
9876 % 100 = 76  , divide by 10 = 7.6 , int(7.6) = 7
9876 % 1000 = 876 , divide by 100 = 8.76  , int(8.76) = 8
9876 % 10000 = 9876 , divide by 1000 = 9.876 , int(9.876) = 9