[問題] 一個關於發牌的問題

[xtimer ()]

因作業遇到困難  想上來請教一下各位大大

題目是一個21點的遊戲
(暫不考慮初始發兩張牌 & 發出的牌重複問題)

先貼一下目前code進度

==============================================================================

public class a1{

        public static void main(String[] args) throws java.io.IOException
{
  char key;
  int r;
  int player = 0;
  int bank = 0;

do{
  r = (int)(Math.random() * (13-1) + 1);
  player += r;
  System.out.print("玩家點數:" + r + "點\t玩家累計:" + player + "點\t");
    if (player > 21)
      {
      System.out.println();
      System.out.println("哇！玩家爆了！莊家贏");
      }else if (player == 21)
      {
      System.out.println();
      System.out.println("玩家21點！玩家贏");
      }else
      {
      System.out.println("是否成要牌(y/n)\t");
      key = (char)System.in.read();
      System.in.read(); System.in.read();
      }
  }
while (key == 'y');

}
             }

==============================================================================

錯在黃色那一行

想請問是否while判斷式裡面  不能用來判斷字元呢?

如果是這樣的話  要怎麼修改~"~



感謝各位大大

補上錯誤訊息
==============================================================================

a1.java:35: variable key might not have been initialized
while (key == 'y');
       ^
1 error

==============================================================================

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◆ From: 218.172.2.245
→ adrianshum:.... 你憑什麼覺得while不能判斷字元?....
回a大

我沒有憑什麼

只是對do while的條件式不理解  沒有書本可以參考

網路上倒是沒找到用來判斷字元的

所以想上來問問看
→ superlubu:「錯」是錯什麼？Exception? Compilation Error?
※ 編輯: xtimer          來自: 218.172.2.245        (12/08 16:09)
推 snowlike:while只能判斷boolean值，不過讓字元的比較回傳T/F就可以
→ tkcn:樓上，原 po 的 source 在這個部份沒有問題
→ ken915007:variable key might not have been initialized...這個
→ neversay:char key = '';
→ ken915007:錯誤訊息寫得很清楚囉!!
→ xtimer:小弟看的一頭霧水...囧rz..
→ ken915007:哇勒...斷掉了= =
推 snowlike:恩正想要怎說；t大回覆得詳細，判斷時知道key是什麼就可
→ xtimer:大概懂了t大的意似  現在的key對程式來說不是個char...
→ xtimer:還是不會轉....囧rz..
→ adrianshum:不是 '不是個char', 而是未初始化....
→ xtimer:key可以直接拿來輸出會顯示y  但不能放進判斷式裡..
→ snowlike:那只有在else的情況，它不是'一定'會被賦值
→ xtimer:完成了...結果最後判斷式是直接給兩個一樣的值做無限迴圈
→ xtimer:直接在裡面判斷  條件不成立的話就直接跳出do-while
→ xtimer:最後還是不懂字元在判斷式裡該怎麼使用..~"~ 謝謝各位大大
=============================================================================


import java.io.*;

public class Number21{

        public static void main(String[] args) throws java.io.IOException
{
  int r, rf;
  int player = 0;
  int bank = 0;
  char key;
  String card;
  String jqk;
do{
  card = "";                                     //初始花色
  jqk = "";                                      //初始人頭點數
  rf = (int)(Math.random() * (4-1) + 1);         //決定牌花色start
      switch(rf)
      {
      case 1:
      card += ((char)6);
      break;
      case 2:
      card += ((char)3);
      break;
      case 3:
      card += ((char)4);
      break;
      case 4:
      card += ((char)5);
      break;                                     //決定牌花色end
      }
  r = (int)(Math.random() * (13-1) + 1);         //發一張牌
        if (r <= 10)
          {
             player += r;
             System.out.print
                ("玩家點數:" + card + r + "\t玩家累計:" + player + "點\t");
          }
        else
          {
             if (r == 11)
             jqk += "J";
             if (r == 12)
             jqk += "Q";
             if (r == 13)
             jqk += "K";
             r = 10;
             player += r;
             System.out.print
                ("玩家點數:" + card + jqk + "\t玩家累計:" + player + "點\t");
          }
    if(player > 21)
      {
      System.out.println("\n哇！玩家爆了！莊家贏");
      break;                                     //爆了，跳出迴圈
    }else if (player == 21)
      {
      System.out.println("\n玩家21點！玩家贏");
      break;                                     //贏了，跳出迴圈
    }else
      {
      System.out.print("是否補牌(y/n)\t");
      key = (char)System.in.read();
      System.in.read(); System.in.read();
      int i = key;
      if (i != 121)                                //判斷輸入值不等於'y'
      break;                                        //就跳出迴圈
      }
  }
while (1 == 1);                                    //直接作成無窮迴圈

if(player < 21)                                    //玩家沒爆，也沒21點
{                                                   //才換莊家補牌
  do{
      card = "";                                   //初始花色
      jqk = "";                                    //初始人頭
       rf = (int)(Math.random() * (4-1) + 1);      //決定牌花色start
         switch(rf)
         {
          case 1:
            card += ((char)6);
            break;
          case 2:
            card += ((char)3);
            break;
          case 3:
            card += ((char)4);
            break;
          case 4:
            card += ((char)5);
            break;                                      //決定牌花色end
        }
       r = (int)(Math.random() * (13-1) + 1);
       if (r <= 10)
          {
             bank += r;
             System.out.print
                ("莊家點數:" + card + r + "\t莊家累計:" + bank + "點\t");
          }
       else
          {
             if (r == 11)
             jqk += "J";
             if (r == 12)
             jqk += "Q";
             if (r == 13)
             jqk += "K";
             r = 10;
             bank += r;
             System.out.print
                ("莊家點數:" + card + jqk + "\t莊家累計:" + bank + "點\t");
          }
                  if (bank > 21)
                  {
                        System.out.println("\n哇！莊家爆了！玩家贏");
                        break;
                  }
                  else if(bank == 21)
                  {
                        System.out.println("\n哇！莊家21點！莊家贏");
                        break;
                  }
                  else
                  {
                      if (bank < player)
                        System.out.println("莊家再補一張牌");
                      else if (bank > player)
                        {
                        System.out.println
                     ("\n莊家" + bank + "點，玩家" + player + "點，莊家贏！");
                        break;
                        }
                      else
                        {
                        System.out.println
                    ("\n莊家及玩家都" + bank + "點，平手！");
                        break;
                        }
                  }
    }
 while (1 == 1);
}
}
               }


==============================================================================
※ 編輯: xtimer          來自: 218.172.2.245        (12/08 19:10)