使用数组创建 DeckOfCards 类

Question

这几天我一直在和这个问题作斗争，希望有人能提供一些指导。第一次在 Java 中使用数组，学习 Java 才两个月左右。要温柔。:)

在我看来，我正在创建一个并行数组，其中用cardName（例如Ace、10、Jack）和suitName（例如Hearts、Spades等）填充cardInDeck[][]。虽然该方法的输出以及我认为写入数组的内容符合预期，但在打印数组内容时，我得到了一些异常结果。

我试图缩小这些意外结果是否是因为我在声明数组时不正确地构造数组，如果我试图创建一个与上帝和自然（或至少是Java）相悖的数组，或者如果数组是正确的，但我不明白如何打印内容。

您能提供的任何帮助将不胜感激。提前致谢！

代码和结果如下所示。

import java.util.*;
import java.lang.*;
//
public class DeckOfCards
{
   public static void main(String[] args)
   {
      int rank;
      int suit;
//
   for(rank=1;rank<14;rank++)
   {
       String tempCardName = Integer.toString(rank);
       String cardName;
       if(rank==1)
       cardName="Ace";
       else
       if(rank==13)
       cardName="King";
       else
       if(rank==12)
       cardName="Queen";
       else
       if(rank==11)
       cardName="Jack";
       else
       cardName=tempCardName;
 //
       for(suit=1;suit<5;suit++)
       {
       String suitName;
       switch(suit)
       {case 1:
   suitName = "Spades";
   break;
   case 2:
   suitName = "Hearts";
   break;
   case 3:
   suitName = "Clubs";
   break;
         case 4:
   suitName = "Diamonds";
   break;
   default:
   suitName = "Error";}
       String tempCardInDeck=(cardName + " of " + suitName);
       System.out.print("method output: " tempCardInDeck);
 //*
       String[][] cardInDeck = new String[][]
          {
             {cardName,suitName}
          };
       System.out.print(" /// to array: " + cardName + " " + suitName);
       System.out.println(" /// from array: " + Arrays.toString( cardInDeck ) );
     }
     }
   }
 }

结果：

method output: Ace of Spades /// to array: Ace Spades /// from array: [[Ljava.lang.String;@9ffb18]
method output: Ace of Hearts /// to array: Ace Hearts /// from array: [[Ljava.lang.String;@11de914]
method output: Ace of Clubs /// to array: Ace Clubs /// from array: [[Ljava.lang.String;@b1406b]
method output: Ace of Diamonds /// to array: Ace Diamonds /// from array: [[Ljava.lang.String;@fc5408]
method output: 2 of Spades /// to array: 2 Spades /// from array: [[Ljava.lang.String;@1f102c1]
method output: 2 of Hearts /// to array: 2 Hearts /// from array: [[Ljava.lang.String;@1ec0130]
method output: 2 of Clubs /// to array: 2 Clubs /// from array: [[Ljava.lang.String;@1420fea]
method output: 2 of Diamonds /// to array: 2 Diamonds /// from array: [[Ljava.lang.String;@230be4]
method output: 3 of Spades /// to array: 3 Spades /// from array: [[Ljava.lang.String;@e1e567]
method output: 3 of Hearts /// to array: 3 Hearts /// from array: [[Ljava.lang.String;@9bfee2]
method output: 3 of Clubs /// to array: 3 Clubs /// from array: [[Ljava.lang.String;@17aaeec]
method output: 3 of Diamonds /// to array: 3 Diamonds /// from array: [[Ljava.lang.String;@1721a26]
method output: 4 of Spades /// to array: 4 Spades /// from array: [[Ljava.lang.String;@12db7c]
method output: 4 of Hearts /// to array: 4 Hearts /// from array: [[Ljava.lang.String;@7c28c]
method output: 4 of Clubs /// to array: 4 Clubs /// from array: [[Ljava.lang.String;@17588d5]
method output: 4 of Diamonds /// to array: 4 Diamonds /// from array: [[Ljava.lang.String;@16a7c99]
method output: 5 of Spades /// to array: 5 Spades /// from array: [[Ljava.lang.String;@1a5d08]
method output: 5 of Hearts /// to array: 5 Hearts /// from array: [[Ljava.lang.String;@d1c9b5]
method output: 5 of Clubs /// to array: 5 Clubs /// from array: [[Ljava.lang.String;@111c3f0]
method output: 5 of Diamonds /// to array: 5 Diamonds /// from array: [[Ljava.lang.String;@156f14c]
method output: 6 of Spades /// to array: 6 Spades /// from array: [[Ljava.lang.String;@fbd1fc]
method output: 6 of Hearts /// to array: 6 Hearts /// from array: [[Ljava.lang.String;@973678]
method output: 6 of Clubs /// to array: 6 Clubs /// from array: [[Ljava.lang.String;@1791620]
method output: 6 of Diamonds /// to array: 6 Diamonds /// from array: [[Ljava.lang.String;@9ba632]
method output: 7 of Spades /// to array: 7 Spades /// from array: [[Ljava.lang.String;@bc5245]
method output: 7 of Hearts /// to array: 7 Hearts /// from array: [[Ljava.lang.String;@1bd523d]
method output: 7 of Clubs /// to array: 7 Clubs /// from array: [[Ljava.lang.String;@6250d2]
method output: 7 of Diamonds /// to array: 7 Diamonds /// from array: [[Ljava.lang.String;@a8198c]
method output: 8 of Spades /// to array: 8 Spades /// from array: [[Ljava.lang.String;@25753d]
method output: 8 of Hearts /// to array: 8 Hearts /// from array: [[Ljava.lang.String;@1341183]
method output: 8 of Clubs /// to array: 8 Clubs /// from array: [[Ljava.lang.String;@169cccc]
method output: 8 of Diamonds /// to array: 8 Diamonds /// from array: [[Ljava.lang.String;@10469e8]
method output: 9 of Spades /// to array: 9 Spades /// from array: [[Ljava.lang.String;@c4fedd]
method output: 9 of Hearts /// to array: 9 Hearts /// from array: [[Ljava.lang.String;@138847d]
method output: 9 of Clubs /// to array: 9 Clubs /// from array: [[Ljava.lang.String;@1826ac5]
method output: 9 of Diamonds /// to array: 9 Diamonds /// from array: [[Ljava.lang.String;@12fb063]
method output: 10 of Spades /// to array: 10 Spades /// from array: [[Ljava.lang.String;@1e55d39]
method output: 10 of Hearts /// to array: 10 Hearts /// from array: [[Ljava.lang.String;@14b525c]
method output: 10 of Clubs /// to array: 10 Clubs /// from array: [[Ljava.lang.String;@c4c05]
method output: 10 of Diamonds /// to array: 10 Diamonds /// from array: [[Ljava.lang.String;@1530551]
method output: Jack of Spades /// to array: Jack Spades /// from array: [[Ljava.lang.String;@18235a1]
method output: Jack of Hearts /// to array: Jack Hearts /// from array: [[Ljava.lang.String;@18ee2ee]
method output: Jack of Clubs /// to array: Jack Clubs /// from array: [[Ljava.lang.String;@1d48043]
method output: Jack of Diamonds /// to array: Jack Diamonds /// from array: [[Ljava.lang.String;@30cd64]
method output: Queen of Spades /// to array: Queen Spades /// from array: [[Ljava.lang.String;@1fc9fee]
method output: Queen of Hearts /// to array: Queen Hearts /// from array: [[Ljava.lang.String;@67f797]
method output: Queen of Clubs /// to array: Queen Clubs /// from array: [[Ljava.lang.String;@1b01949]
method output: Queen of Diamonds /// to array: Queen Diamonds /// from array: [[Ljava.lang.String;@4c2849]
method output: King of Spades /// to array: King Spades /// from array: [[Ljava.lang.String;@1e8f2a0]
method output: King of Hearts /// to array: King Hearts /// from array: [[Ljava.lang.String;@90f19c]
method output: King of Clubs /// to array: King Clubs /// from array: [[Ljava.lang.String;@1e67280]
method output: King of Diamonds /// to array: King Diamonds /// from array: [[Ljava.lang.String;@675039]

Answer 1

您在输出中看到的是默认实现 toString. 。从 文档 为了 Arrays:

返回指定数组内容的字符串表示形式。如果数组包含其他数组作为元素，则它们会通过继承自 Object 的 Object.toString() 方法转换为字符串，该方法描述它们的标识而不是它们的内容。

因为它是默认版本 目的, ，你会得到的是...

Object 类的 toString 方法返回一个字符串，该字符串由对象所属的类的名称、at 符号“@”以及对象哈希码的无符号十六进制表示形式组成。

正如另一个答案中所建议的， Arrays.deepToString 应该是你所追求的。这对我来说实际上是一个新事物，所以我会亲自尝试一下。

Answer 2

如果要打印数组的内容，则应使用 Arrays.deepToString(cardInDeck) 而不是世代odicetagcode。

Answer 3

实现卡片甲板的另一种方法是使用枚举，这允许编译器强制为您进行类型检查，这是一个非常好的做法。查看 Oracle的Java教程 cards ， deck ，以及显示在这些链接。