public class ExceptionTest { public static void main(String[] args) { Scanner sc=new Scanner(System.in); try { System.out.println("你的選擇是:A,B,C,D"); String s=sc.next(); if(s=="a"){ System.out.println("選擇正確"); } else{ System.out.println("選擇錯誤"); } } catch (InputMismatchException e) { System.out.println("請重新輸入"); } }}