我正在尝试制作两个类别的测验程序：Java或C ++。我想用4个答案（多项选择）提出一个问题，但我不知道该条件将如何运作以及如何保存用户分数。
该应用程序使用JOptionPane与用户进行交互。
这是我到目前为止：
import javax.swing.JOptionPane;
public class Quiz1
{
public static void main(String[] args)
{
int score = 0;
JOptionPane.showMessageDialog(null,"WELCOME");
String name = JOptionPane.showInputDialog(null,"Enter Your Name: ");
String [] Intro = new String [] {"JAVA","C++"};
int option = JOptionPane.showOptionDialog(null, "Choose a Category" , "Menu", JOptionPane.YES_NO_OPTION, JOptionPane.PLAIN_MESSAGE, null, Intro, Intro[0]);
if (option == JOptionPane.YES_OPTION) // I just make YES or NO option since there are 2 choices
{
JOptionPane.showMessageDialog(null, "Hello "+ name + "\n Welcome to Java Quiz!");
JOptionPane.showMessageDialog(null, "1. Please read the questions carefully \n 2. Answer all the question \n 3. Scores will be computed after the quiz \n 4. No Cheating!","RULES",JOptionPane.WARNING_MESSAGE);
JOptionPane.showMessageDialog(null, "This Quiz consist of \n 1. Multiple Choice \n 2.Enumeration \n 3. True/False");
JOptionPane.showMessageDialog(null,"Quiz #1: Enter the correct letter of the answer");
// STRING OF QUESTIONS
String[] quesJava = new String [] {"1) The JDK command to compile a class in the file Test.java is", "2) Java was developed by_____."};
String[] answers1 = new String[] {"A) java Test.java", "B) java Test","C) javac Test","D) javac Test.java"};
int answer1 = JOptionPane.showOptionDialog(null, quesJava[0], "JAVA", JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE, null, answer1, answer1[0]);
if (answer1== ???????????) // the answer is letter "D" but I don't know what will I put in here
{
score++;
}
String[] answer2 = new String[] {"A) IBM ", "B) Microsoft ","C) Sun Microsystem ","D) Oracle"};
int answer2 = JOptionPane.showOptionDialog(null, quesJava[1], "JAVA", JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE, null, answer2, answer2[0]);
{
if (answer2== )
{
score++;
}
}
JOptionPane.showMessageDialog(null,"your score is"+score);
}
}
}
答案 0 :(得分：0)
好吧，如果你看一下你可能看到的documentation of JOptionPane：
public Object[] getSelectionValues()：
返回输入选择值。
返回用户选择的值。
UNINITIALIZED_VALUE表示用户尚未做出选择，null表示用户关闭窗口而未选择任何内容。否则返回的值将是此对象中定义的选项之一。
这使您的问题很容易解决。
答案 1 :(得分：0)
我要重写你提供的代码，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： 根据所选语言询问随机问题。
它是如何做到的：
首先询问用户：他们的名字和他们想要被提问的语言。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）
在类的最顶层，我们有两个存在问题的数组，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，只需向数组中添加一个新问题。
调用方法askQuestions(int maxScore)。首先从方法getRandomQuestion(Language lang)中获取一个随机问题，然后调用方法ask(Question question)，向用户显示问题并返回是否正确。如果他们得到了正确的话，score变量会增加，并且会有一个对话框告诉他们他们是正确的，如果他们弄错了，会出现一个对话框，告诉他们正确的答案。这会循环您使用变量maxScore 指定的次数（这应该低于数组中的问题数量）。
代码记录得非常好，可以指导您完成所发生的事情。
您必须稍微使用代码才能完全理解它，但在大多数情况下，您想要的只是相当简单。