java - 我的循环出现问题，想要以正确的选择终止(JAVA)

Question

import javax.swing.JOptionPane;

public class Quiz {

    public static void main(String[] args) {

        String question = ("How many states are there in the United States of America?\n");
        question += "A. There are 48 states.\n";
        question += "B. There are 50 states.\n";
        question += "C. There are 52 states.\n";
        question += "D. There are 13 states.\n";
        question += "E. There are 26 states.\n";

    while (true) {
        String answer = JOptionPane.showInputDialog(question);
        answer = answer.toUpperCase();
        if (answer.equals("B")) {
            JOptionPane.showMessageDialog(null,"Correct!");}
        switch (answer) 
            {
            //case "B":
                //JOptionPane.showMessageDialog(null,"Correct!");
                //break;
            case "A": 
                JOptionPane.showMessageDialog(null,"You chose A, that is incorrect. Please try again");
                break;
            case "C":  
                JOptionPane.showMessageDialog(null,"You chose C, that is incorrect. Please try again");
                break;
            case "D":
                JOptionPane.showMessageDialog(null,"You chose D, that is incorrect.Please try again");
            break;
            case "E": 
                JOptionPane.showMessageDialog(null,"You chose E, that is incorrect.Please try again");
            break;
            default:
                JOptionPane.showMessageDialog(null,"You made an invalid selection, please enter A,B,C,D, or E.");
                break;
            }


        }
        }
    }

我试图让程序在选择正确答案后停止询问问题。如果选择了错误的选择，我希望出现问题，直到用户选择正确的答案，然后让程序终止。现在，我在选择正确答案后出现“默认”语句，并且它不会终止。

Answer 1

如果您知道当答案为 B 时您的程序将终止，则应该删除 while(true)，并且也许可以执行类似的操作。

import javax.swing.JOptionPane;

public class Quiz {

    public static void main(String[] args) {

        String question = ("How many states are there in the United States of America?\n");
        question += "A. There are 48 states.\n";
        question += "B. There are 50 states.\n";
        question += "C. There are 52 states.\n";
        question += "D. There are 13 states.\n";
        question += "E. There are 26 states.\n";
        String answer = "";
        // This will work with 'B' and 'b' because your setting your answer to uppercase
        while (!answer.equals("B")) {
            answer = JOptionPane.showInputDialog(question);
            answer = answer.toUpperCase();
            switch (answer) {
                case "B":
                    JOptionPane.showMessageDialog(null,"Correct!");
                    break;
                case "A":
                    JOptionPane.showMessageDialog(null,"You chose A, that is incorrect. Please try again");
                    break;
                case "C":
                    JOptionPane.showMessageDialog(null,"You chose C, that is incorrect. Please try again");
                    break;
                case "D":
                    JOptionPane.showMessageDialog(null,"You chose D, that is incorrect.Please try again");
                    break;
                case "E":
                    JOptionPane.showMessageDialog(null,"You chose E, that is incorrect.Please try again");
                    break;
                default:
                    JOptionPane.showMessageDialog(null,"You made an invalid selection, please enter A,B,C,D, or E.");
                    break;
            }


        }
    }
}

由于注释了 B case 行，您可能会得到默认语句。