我将重写您提供的代码以使这更容易...
这是最终结果：
import java.util.Random;
import javax.swing.JOptionPane;
public class Quiz {
/**
* This holds all the java questions.
*/
private static final Question[] JAVA_QUESTIONS = new Question[]{
new Question("Who developed Java?", 2, "Google", "Sun Microsystems", "Microsoft", "Oracle"),
//This creates the question: Who developed java with 4 answers (google, Sun, Microsoft and Oracle)
//The correct answer is 2 (Sun).
new Question("What modifier is used to make a variable constant?", 3, "public", "abstract", "final", "import")
};
/**
* This holds all the c++ questions.
*/
private static final Question[] CPP_QUESTIONS = new Question[]{
new Question("C++ is?", 4, "Interpreted", "A scripting language", "The first programming language", "Compiled")
};
/**
* The users score
*/
private int score;
/**
* The users name
*/
private String name;
/**
* What language the user selected.
*/
private Language lang;
private Quiz() {
setLookAndFeel();//Makes everything look nice
showOpeningDialogs();//Shows the welcome dialogs
askQuestions(10);//Asks random questions 10 times depending on what language is selected.
}
/**
* Asks random questions depending on the language chosen.
*
* @param maxScore the number of questions to ask
*/
private void askQuestions(int maxScore) {
for (int i = 0; i < maxScore; i++) {
Question q = getRandomQuestion(lang);//Gets a random question for the language chosen.
if (ask(q)) {//Checks if they got it correct
JOptionPane.showMessageDialog(null, "You answered correctly");//Tell them they got it correct
score++;//Increment their score.
} else {//If they got it wrong
JOptionPane.showMessageDialog(null, "You answered incorrectly. The answer is: " + q.getChoices()[q.getCorrectAnswer()]);
//Tell them they got it wrong and what the correct answer is.
}
}
JOptionPane.showMessageDialog(null, "Your score is: " + score + "/" + maxScore);//At the end, tell them their score
}
/**
* Asks a question and returns whether the player got it correct.
*
* @param question
* @return
*/
private boolean ask(Question question) {
//Shows a dialog with the question and answers.
int choice = JOptionPane.showOptionDialog(
null,
question.getQuestion(),
lang.getDisplayName(),
JOptionPane.DEFAULT_OPTION,
JOptionPane.QUESTION_MESSAGE,
null,
question.getChoices(),
question.getChoices()[0]);
//Checks to see if the answer is correct. This is determined by the answer variable in the question object.
if (choice == question.getCorrectAnswer()) {
return true;
}
return false;
}
/**
* Just makes everything look nice. You don't have to worry about this.
*/
private void setLookAndFeel() {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if (/**What java look and feel*/
"Windows".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
//Very unlikely to happen
}
}
/**
* Shows the welcome dialogs and so on.
*/
private void showOpeningDialogs() {
name = JOptionPane.showInputDialog(null, "Welcome.\nPlease enter you name:");//Gets the users name.
String[] langs = new String[]{Language.JAVA.getDisplayName(), Language.CPP.getDisplayName()};
int opt = JOptionPane.showOptionDialog(null, "Please chose your language", "Menu", JOptionPane.YES_NO_OPTION, JOptionPane.PLAIN_MESSAGE, null, langs, langs[0]);//Gets the language the user chose.
//Set the language depending on the users choice.
switch (opt) {
case JOptionPane.YES_OPTION:
lang = Language.JAVA;
break;
default:
lang = Language.CPP;
}
//The instructions.
JOptionPane.showMessageDialog(null, "Hello " + name + "\nWelcome to the " + lang.getDisplayName() + " Quiz!");
JOptionPane.showMessageDialog(null, "1. Please read the questions carefully \n2. Answer all the question \n3. Scores will be computed after the quiz \n4. No Cheating!", "RULES", JOptionPane.WARNING_MESSAGE);
JOptionPane.showMessageDialog(null, "This Quiz consist of \n 1. Multiple Choice");
//Do they want to continue
int begin = JOptionPane.showOptionDialog(null, "Are you ready to begin?", "Menu", JOptionPane.YES_NO_OPTION, JOptionPane.PLAIN_MESSAGE, null, new String[]{"Yes", "No"}, "Yes");
if (begin != JOptionPane.YES_OPTION) {
System.exit(0);
}
}
/**
* Gets a random question for a language
*
* @param lang the language
* @return a random question
*/
private Question getRandomQuestion(Language lang) {
switch (lang) {
case JAVA://If the language is java, choose a java question.
int random = new Random().nextInt(JAVA_QUESTIONS.length);
return JAVA_QUESTIONS[random];
case CPP://Else choose a C++ question.
random = new Random().nextInt(CPP_QUESTIONS.length);
return CPP_QUESTIONS[random];
}
return null;
}
public static void main(String[] args) {
Quiz q = new Quiz();//Just starts the application.
}
/**
* This class holds a question, the correct answer and the choices.
*/
private static final class Question {
/**
* The question being asked
*/
private final String question;
/**
* The correct choice. The index of the choices array.
*/
private final int correctAnswer;
/**
* The 4 choices the player can choose
*/
private final String[] choices;
public Question(String question, int correctAnswer, String... choices) {
if (question == null) {
throw new NullPointerException("The question cannot be null");
}
if (correctAnswer < 1 || correctAnswer > 4) {
throw new IllegalArgumentException("Correct answer must be between 0 and 5 (1 to 4)");
}
if (choices == null) {
throw new NullPointerException("choices cannot be null");
}
if (choices.length != 4) {
throw new NullPointerException("Choices must have 4 options");
}
this.question = question;
this.correctAnswer = correctAnswer - 1;
this.choices = choices;
}
/**
* @return the question
*/
public String getQuestion() {
return question;
}
/**
* @return the correctAnswer
*/
public int getCorrectAnswer() {
return correctAnswer;
}
/**
* @return the choices
*/
public String[] getChoices() {
return choices;
}
}
/**
* Which language we're using
*/
private enum Language {
/**
* The Java programming language
*/
JAVA("Java"),
/**
* The C++ programming language
*/
CPP("C++");
//The display name for the language
private final String displayName;
Language(String displayName) {
this.displayName = displayName;
}
public String getDisplayName() {
return displayName;
}
}
}
它的作用：
根据所选语言随机提问。
它是如何做到的：
首先询问用户：他们的姓名和他们想要被测试的语言。这是在showOpeningDialogs() 方法中完成的。他们在变量name 和lang 中提供的信息。
然后继续提问（重要部分）
在类的最顶端，我们有两个存放问题的数组，一个用于 Java(JAVA_QUESTIONS)，另一个用于 C++(CPP_QUESTIONS)。这些数组包含问题、答案和正确答案。要添加更多问题，您只需向数组中添加一个新问题即可。
方法askQuestions(int maxScore) 被调用。它首先从方法getRandomQuestion(Language lang) 获取一个随机问题，然后调用方法ask(Question question) 向用户显示问题并返回他们是否正确。如果他们做对了，score 变量就会增加，并且一个对话框告诉他们他们做对了，如果他们做错了，一个对话框会出现，告诉他们正确的答案。这会循环您使用变量maxScore 指定的次数（这可能低于数组中的问题数）。
代码记录得很好，可以指导您了解正在发生的事情。
您将不得不对代码进行一些操作才能完全理解它，但在大多数情况下，您想要的内容相当简单。