我怎么做到这样我的测验让我回答？

Question

我是一名初学程序员,我正在尝试编写一个简单的程序,询问一个问题,然后在输入对话框中输入"A","B"或"C"的形式提示您回答该问题,但没有出现对话框.其他一切似乎都很好.

这是我的代码:

package homework;

import javax.swing.JOptionPane;

public class Quiz {

    public static void main(String[] args) 
    {


    int x = 0;
    String[] quizQuestion = {"What is the color of the sky?", "What is the         
        color of the sea?", "What is the color of the earth?"};
    int score = 0;
    String correct = "You are correct";
    String incorrect = "You are incorrect";
    String playerAnswerString = " ";
    playerAnswerString.toUpperCase();
    char playerAnswer = playerAnswerString.charAt(0);

    JOptionPane.showMessageDialog(null, "Test Your Knowledge!");
    JOptionPane.showMessageDialog(null, "Select an answer to the questions.");
    for(x = 0; x < 3; x++)
    {
        JOptionPane.showMessageDialog(null, quizQuestion[x]);
        while(quizQuestion.equals(0))
        {
            playerAnswerString = JOptionPane.showInputDialog(null, "A = Blue, B = Green, C = Brown");
            if(playerAnswer == 'A')
            {
                JOptionPane.showMessageDialog(null, correct);
                score++;
            }
            else
            {
                JOptionPane.showMessageDialog(null, incorrect);
            }
        }
        while(quizQuestion.equals(1))
        {
            playerAnswerString = JOptionPane.showInputDialog(null, "A = Blue, B = Green, C = Brown");
            if(playerAnswer == 'B')
            {
                JOptionPane.showMessageDialog(null, correct);
                score++;
            }
            else
            {
                JOptionPane.showMessageDialog(null, incorrect);
            }
        }
        while(quizQuestion.equals(2))
        {
            playerAnswerString = JOptionPane.showInputDialog(null, "A = Blue, B = Green, C = Brown");
            if(playerAnswer == 'C')
            {
                JOptionPane.showMessageDialog(null, correct);
                score++;
            }
            else
            {
                JOptionPane.showMessageDialog(null, incorrect);
            }
        }
    }
    JOptionPane.showMessageDialog(null, "You scored " + score + "/3.");


}
}

提前致谢.

编辑清晰.

Answer 1

char playerAnswer = playerAnswerString.charAt(0);

用户在此处选择答案后,您必须指定playerAnswer的值

playerAnswerString = JOptionPane.showInputDialog(null, "A = Blue, B = Green, C = Brown");

否则变量playerAnswer将为空