public class Test {?? ?public static void main(String[] args) {? ????? System.out.println(test3());?? ?}?? ?public static? int test3(){?? ?????? try{return 20;? }catch(Exception e){??????????? e.printStackTrace();??????????? System.out.println("循環拋出異常了?。。?);???????? ??????? }finally{??????????? System.out.println("這是finally?。?！哈哈?。?！");??????? ??????? }?? ??? ?return 0;//問題是這里的return0；如果注釋掉程序會出錯。??? }}程序有點亂，大家不要介意，我得主要問題就是在test3方法try中已經有了返回值return 20；為什么在下面一定要加上return0；呢？如果不加程序會提示錯誤，并且在下面的程序中沒有添加return 30；就沒有問題，這是為什么呢？public class Test3 {?? ?public static void main(String[] args){?? ??? ?System.out.println(test());?? ?}?? ?public static String test(){?? ??? ?try{?? ??? ??? ?System.out.println("try block");?? ??? ??? ?return "20";?? ??? ?}finally{?? ??? ??? ?System.out.println("finally block");?? ??? ?}?????? //return 30； ? ? ?? }}