import java.util.*;?class Cardclass{ public String ID; public String color; public Cardclass(String ID , String color){ this.ID = ID; this.color = color; }}class Card{ static List<Cardclass> newcard; public Card(){ this.newcard = new ArrayList<Cardclass>(); } public void add(){ int i; int j; int n=0; String[] IDs=new String[13]; IDs[0] = "A"; IDs[1] = "2"; IDs[2] = "3"; IDs[3] = "4"; IDs[4] = "5"; IDs[5] = "6"; IDs[6] = "7"; IDs[7] = "8"; IDs[8] = "9"; IDs[9] = "10"; IDs[10] = "J"; IDs[11] = "Q"; IDs[12] = "K"; String[] color=new String[4]; color[0] = "Black"; color[1] = "Red"; color[2] = "Plum"; color[3] = "Square"; for(i = 0 ; i < 13 ; i++){ for(j = 0 ; j < 4 ; j++){ Cardclass cc = new Cardclass(IDs[i],color[j]); newcard.add(cc);? Cardclass outPut = (Cardclass)newcard.get(n); System.out.println(outPut.ID + " ?" + outPut.color); n++; } } }}class people extends Card{ public int Num; public String Name; public String id; public String color; public people(int x , String y ,String newID , String newcolor){ Num = x; Name = y; System.out.println("1"); id = newID; color = newcolor; }}public class tp extends Card{ public static void main(String[] args){ int i; int j; int n=0; Card cd = new Card(); cd.add(); System.out.println("*********************"); Scanner input = new Scanner(System.in); for(i = 0 ; i < 2 ;i++){ System.out.println("請輸入玩家序號"); int newnum = input.nextInt(); System.out.println("請輸入玩家名字"); String newname = input.next(); Cardclass newcd = (Cardclass)newcard.get(n); ? // 第二次執行時候會提示越界 String newID = newcd.ID;? String newcolor = newcd.color; people newpeople = new people(newnum , newname , newID , newcolor); System.out.println(newpeople.Num+" "+newpeople.Name+" "+newpeople.id+" "+newpeople.color); n++; } }}問題在注釋那句 ?剛剛學不是很懂 - -！