Question

public class BlackJack {
    public static void main(String args[]) {
        String input;
        char reDo;
        Scanner keyboard = new Scanner (System.in);
        Random random = new Random();
        int card1 = random.nextInt(10) + 1;
        int card2 = random.nextInt(10) + 1;
        int card = random.nextInt(10) + 1;
        int total1 = card1 + card2;
        int total2 = total1 + card;

        System.out.print("First cards: " + card1 + ", " + card2 + "\n");
        System.out.print("Total: " + total1 + "\n");

        boolean loop = true;
        while (loop) {
            System.out.print("Do you want another card? (y/n): ");
            input = keyboard.nextLine();
            reDo = input.charAt(0);
            if (reDo == 'y' || reDo == 'Y') {
                System.out.print("Card: " + card + "\n");
                System.out.print("Total: " + total2 + "\n");
            } else if (reDo == 'n' || reDo == 'N') {
                loop = false;
            }
        }
    }
}

输出如下：

第一张牌：8,3   总计：11
  你想要另一张卡吗？（是/否）：y
  卡片：7
  总计：18
  你想要另一张卡吗？（是/否）：y
  卡片：7
  总计：18
  你想要另一张卡吗？（y / n）：n

我希望能够在循环中生成新的随机卡，显示重复总计，并停止程序。我无法理解的问题是如何使用random.nextInt工具并能够更方便地重用它。目前它卡住了card1，card2，card，total1和total2。如果我可以制作它们以便我可以更轻松地访问它们，那么我认为编写程序会更容易。问题是我无法理解如何在while循环中重复random.nextInt。

Answer 1

首先将所有牌放入牌组中。

然后在0和卡组中的卡数之间生成一个随机数。

如果deck是一个ArrayList（例如），你可以做

import java.util.*;


public class Main
{

    public static void main(String[] args)
    {
        List<Card> deck = new ArrayList<Card>();
        deck.add(new Card(1));
        deck.add(new Card(3));
        deck.add(new Card(7));
        deck.add(new Card(10));

        Random randomGenerator = new Random(); 

        System.out.println("Deck 1 tests");
        // draw 3 cards:
        for (int i = 0; i < 3; i++)
        {
            int randomCard = randomGenerator.nextInt(deck.size());
            Card card = deck.remove(randomCard);
            System.out.println("Removed a(n) "+card);
        }

        // you could also do
        List<Card> deck2 = new ArrayList<Card>();
        deck2.add(new Card(1));
        deck2.add(new Card(7));
        deck2.add(new Card(3));
        deck2.add(new Card(10));

        Collections.shuffle(deck2);
        System.out.println("Deck 2 tests");
        // draw 3 cards:
        for (int i = 0; i < 3; i++)
        {
            Card card = deck2.remove(0);
            System.out.println("Removed a(n) "+card);
        }


    }

}

class Card {
    public Card(int i)
    {
        blackJackValue = i;
    }

    public int blackJackValue;

    public String toString() {
        return String.valueOf(blackJackValue);
    }
}

BlackJack java random.nextInt

1 个答案: