import java.util.Scanner; //给一个不多于5位的正整数,要求:一、求它是几位数,二、逆序打印出各位数字。 public class Test { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int num = 0 ; String s = "0"; System.out.println("请一个输入整数:"); while (true) { s = sc.nextLine(); try { num = Integer.parseInt(s); break; } catch (NumberFormatException e) { System.out.println("输入非法,请重新输入整数:"); } } System.out.println(num+"整数的长度为:"+s.length()); StringBuffer sb = new StringBuffer(); sb.append(s); sb.reverse(); System.out.println(sb.toString()); } }