练习2.1

import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        Scanner Hy=new Scanner(System.in);
        String Hyper;
        System.out.println("请输入一个0-1000的整数来求整数各位数的和");
        Hyper = Hy.nextLine();
        int test = Integer.valueOf(Hyper);
        if(test > 0 && test <= 1000) {
            int a = test % 2;
            int b = test / 10;
            int c = test / 100;
            System.out.println("总和为：" + (a + b + c));
        }
        else {
            System.out.println("完成！");
        }

　　}
}