如何从列表中选择随机字符串

Question

我正在尝试创建一个程序，以刺激从卡组中拾取卡片。 我尝试使用Random类来选择suit和rank但我无法使其正常工作。 到目前为止，这是我的代码。

   String[] rank = {"Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10",  "Jack", "Queen", "King"};
   int idx = new Random().nextInt(rank.length);
   String random = (rank[idx]);

   String[] suit = {"Clubs", "Diamonds", "Hearts", "Spades"};
   int idx = new Random().nextInt(suit.length);
   String random = (suit[idx]);

   System.out.println("The card you picked is " + Arrays.toString(rank) + " of " + Arrays.toString(suit));

我敢肯定这很简单，但是我对Java来说还比较陌生，因此可以提供任何帮助！

Answer 1

您做对了。 您只需要打印正确的变量：

String[] rank =  // ...
int rankIndex = new Random().nextInt(rank.length);
String randomRank = rank[rankIndex];

String[] suit = // ...
int suitIndex = new Random().nextInt(suit.length);
String randomSuit = suit[suitIndex];

System.out.println("The card you picked is " + randomRank + " of " + randomSuit);

Answer 2

问题在这里： System.out.println("The card you picked is " + Arrays.toString(rank) + " of " + Arrays.toString(suit)); 。 您每次都在打印项目的完整列表。

您需要做的是放置(rank[idx])和(suit[idx]); 转换成字符串变量并打印出来。

    String[] rank = {"Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King"};
    int idx = new Random().nextInt(rank.length);
    String randomRank = (rank[idx]);

    String[] suit = {"Clubs", "Diamonds", "Hearts", "Spades"};
    idx = new Random().nextInt(suit.length);
    String randomSuit = (suit[idx]);
    System.out.println("The card you picked is " + randomRank + " of " + randomSuit);

Answer 3

请确保添加有什么问题，但您没有包括遇到的问题。

但我期望是这样的：

1）随机两次声明字符串2）不需要Arrays.toString（）

System.out.println("The card you picked is " + **Arrays.toString(rank)** + " of " + Arrays.toString(suit));

为什么要使用Arrays.ToString（）？

 String rankstr = (rank[idx]);
 String suitStr = (suit[idx]);
    System.out.println("The card you picked is " + rankStr + " of " + suitStr);

Answer 4

您要重复变量名称idx和random ，选择不同的名称并像这样输出：

System.out.println("The card you picked is " +random2+ " of " +random);
//The card you picked is 2 of Spades

---

实时Java示例：

http://ideone.com/9asht6