语句练习题2

 1         Scanner sc = new Scanner(System.in);
 2         System.out.println("请输入一个不多于5位的正整数：");
 3         int num = sc.nextInt();
 4         if (num > 99999||num<0) {
 5             System.out.println("你输入的数字有误，请重新输入！");
 6         } else {
 7             Integer s = new Integer(num);
 8             String str = s.toString();
 9             System.out.println("你输入了一个" + str.length() + "位数。");
10             System.out.println("输入的正整数倒序输出：");
11             for (int i = str.length() - 1; i >= 0; i--) {
12                 System.out.print(str.charAt(i));
13             }
14         }