2021108作业

计一个程序, 给定一个整数n(0 选择1: 求n是几位数
选择2: 分别输出n的每一位数字
选择3: 将n反转后输出
样例输入:
123
1
样例输出:
3
样例输入:
123
2
样例输出
1, 2, 3
样例输入:
123
3
样例输出:
321

public class Task108 {
     
	public static void main(String[] args) {
     
		Scanner input = new Scanner(System.in);
		System.out.println("请输入一个(0);
		int num = input.nextInt();
		while (!(num > 0 && num < 100000)) {
     
			System.out.println("输入错误，请重新输入：");
			num = input.nextInt();
		}
		
		String nums = Integer.toString(num);
		while (true) {
     
			System.out.println("1:求n是几位数；2：分别输出n的每一位数字;3:将n反转后输出");
			System.out.println("请输入你的选择：");
			int choice = input.nextInt();
			switch (choice) {
     
			case 1:
				System.out.println(nums.length());
				break;
			case 2:
				for (int i = 0; i < nums.length(); i++) {
     
					System.out.println(nums.charAt(i));	
				}
				break;
			case 3:
				StringBuilder sb = new StringBuilder(nums);
				String reverse = sb.reverse().toString();
				for (int i = 0; i <reverse.length(); i++) {
     
					System.out.println(reverse.charAt(i));	
				}
				break;
			}

		}
	}