I'm trying to make quiz program with two categories: Java or C++. I want to make a question with 4 answers (multiple choice), but I don't know how the condition will work and how the users score will be saved.
The application uses JOptionPanes to interact with the user.
This is what i have so far:
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);
}
}
}
I'm going to rewrite the code you provided to make this slightly easier...
This is the final result:
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;
}
}
}
What it does: Asks random questions depending on the language chosen.
How it does it:
It starts by asking the user: their name and the language they want to be quizzed on. This is done in the showOpeningDialogs() method. The information they provided in the in the variables name and lang.
It then proceeds to asking questions (The important part)
At the very top of the class we have two arrays that hold questions, one for Java(JAVA_QUESTIONS) and the other for C++(CPP_QUESTIONS). These arrays hold the questions, answers and the correct answer. To add more questions you simply add a new question to the array.
The method askQuestions(int maxScore) is called. It starts by getting a random question from the method getRandomQuestion(Language lang), then it calls the method ask(Question question) which shows the question to the user and returns whether they got it correct. If they got it correct the score variable is incremented and a dialog tells them they got it correct, if they got it wrong a dialog will appear telling them the correct answer. This loops for how ever many times you specified with the variable maxScore (this should probably be lowers than the number of questions in the array).
The code is documented quite well as to guide you through what is happening.
You will have to play with the code a bit to get a complete understanding of it but for the most part, what you want is rather simple.