Question

我正在创建一个简单的Blackjack java程序，我很难接受while循环输入验证。当要求用户绘制卡片时，他/她可以选择：（y / n）以及是否想要再次播放。我的问题是，当我被提示画一张卡片而我选择了y时，那个角色只会提示画一张卡片......但似乎任何角色都会这样做。如果我想再次播放，播放循环也是如此。此外，当我被提示再次播放时，我想返回到while循环的开头，但我似乎无法调用该函数。我需要帮助！这是我的代码：

    import java.util.Random;
import java.util.Scanner;

public class BlackJack
{

    public static void main(String[] args)
    {

        char play = 'y';
        char drawAgain;
        int card1, card2;
        int nextCard = 0;


        Scanner keyboard = new Scanner(System.in);
        Random number = new Random();


        while (play != 'n')
        {
            card1 = number.nextInt(10) + 1;
            card2 = number.nextInt(10) + 1;

            System.out.print("First cards: ");
            System.out.println(card1 + ", " + card2);
            int cardTotal = card1 + card2;
            System.out.println("Total: " + cardTotal);
            System.out.print("Draw again? (y/n): ");
            drawAgain = keyboard.next().charAt(0);

            while (drawAgain != 'n')
            {
                int card3 = number.nextInt(10) + 1;
                System.out.println("Card: " + card3);
                cardTotal += card3;
                System.out.println("Total: " + cardTotal);

                if (cardTotal <= 21) {
                    System.out.print("Draw Again? (y/n): ");
                    drawAgain = keyboard.next().charAt(0);

                }

                if (cardTotal > 21) {
                    System.out.println("Bust");
                    System.out.print("Would you like to play again? (y/n): ");
                    play = keyboard.next().charAt(0);
                }


            }


        }
    }
}

Answer 1

此代码存在一些问题。

您将产生无限循环，因为如果点值为＆gt;则drawAgain永远不会重置为n。 21.
为了强制执行，用户必须指定是或否，您必须检查它。下面是一个while循环。
播放变量永远不会重置，这会强制用户播放直到破坏，然后选择是否要继续播放。

以下解决了这些问题。这应该是你想要的。

import java.util.Random;
import java.util.Scanner;

public class BlackJack
{
public static char getValidInput(){
    Scanner keyboard = new Scanner(System.in);

    String input = keyboard.next();
    while(!input.equals("yes") || !input.equals("no")){

        System.out.println("please input yes or no");
        input = keyboard.next();
    }
    return input.charAt(0);
}

public static void main(String[] args)
{

    char play = 'y';
    char drawAgain;
    int card1, card2;
    int nextCard = 0;


    Random number = new Random();

    while (play != 'n')
    {
        card1 = number.nextInt(10) + 1;
        card2 = number.nextInt(10) + 1;

        System.out.print("First cards: ");
        System.out.println(card1 + ", " + card2);
        int cardTotal = card1 + card2;
        System.out.println("Total: " + cardTotal);
        System.out.print("Draw again? (y/n): ");


        drawAgain = getValidInput();
        while (drawAgain != 'n')
        {
            int card3 = number.nextInt(10) + 1;
            System.out.println("Card: " + card3);
            cardTotal += card3;
            System.out.println("Total: " + cardTotal);

            if (cardTotal <= 21) {
                System.out.print("Draw Again? (y/n): ");

                drawAgain = getValidInput();
            }else{ //if (cardTotal > 21) {
                System.out.println("Bust");
                drawAgain ='n';
            }
        }
        play = getValidInput();
    }
}
}

Blackjack.java while循环输入验证

1 个答案: