Assignment is in the Upload This is the previous asignment required for this assignment File ‘Question.java’:   imp

File "Question.java":

import javax.swing.JOptionPane;

public abstract class Question {

static int nQuestions = 0;

static int nCorrect = 0;

String question;

String correctAnswer;

abstract String ask();

void check() {

nQuestions++;

String answer = ask();

if (answer.equals(correctAnswer)) {

JOptionPane.showMessageDialog(null,"Correct!");

nCorrect++;

} else {

JOptionPane.showMessageDialog(null,"Incorrect. The correct answer is

"+correctAnswer+".");

} }

static void showResults() {

JOptionPane.showMessageDialog(null,nCorrect+" correct out of "+nQuestions+"

questions");

} }

File "TrueFalseQuestion.java".

import javax.swing.JOptionPane;

public class TrueFalseQuestion extends Question {

String ask() {

while (true) {

String answer = JOptionPane.showInputDialog(question);

answer = answer.toUpperCase();

f (answer.equals("T") || answer.equals("Y") || answer.equals("YES")) answer = "TRUE";

if (answer.equals("F") || answer.equals("N") || answer.equals("NO")) answer = "FALSE";

boolean valid = (answer.equals("FALSE") ||

answer.equals("TRUE"));

if (valid) return answer;

JOptionPane.showMessageDialog(null,"Invalid answer. Please enter TRUE or FALSE.");

} }

TrueFalseQuestion(String question, String answer) {

this.question = "TRUE or FALSE: "+question;

answer = answer.toUpperCase();

if (answer.equals("T") || answer.equals("TRUE") || answer.equals("Y") ||

answer.equals("YES")) correctAnswer = "TRUE";

if (answer.equals("F") || answer.equals("FALSE") || answer.equals("N") ||

answer.equals("NO")) correctAnswer = "FALSE";

} }

File "MultipleChoiceQuestion.java"

import javax.swing.JOptionPane;

public class MultipleChoiceQuestion extends Question {

MultipleChoiceQuestion(String query, String a, String b, String c, String d, String e,

String answer) {

question = query+"n";

question += "A. "+a+"n";

question += "B. "+b+"n";

question += "C. "+c+"n";

question += "D. "+d+"n";

question += "E. "+e+"n";

correctAnswer = answer.toUpperCase();

}

String ask() {

while (true) {

String answer = JOptionPane.showInputDialog(question);

answer = answer.toUpperCase();

boolean valid = (answer.equals("A") || answer.equals("B") || answer.equals("C") ||

answer.equals("D") || answer.equals("E"));

if (valid) return answer;

JOptionPane.showMessageDialog(null,"Invalid answer. Please enter A, B, C, D, or E.");

        }

   }

}

File "Quiz.java".

public class Quiz {

public static void main(String[] args) {

fun!","y");

Question question = new TrueFalseQuestion("Quizzes are

question.check();

question = new TrueFalseQuestion("Quizzes are more fun than programming!","n");

T?","t");

F?","f");

question.check();

question = new TrueFalseQuestion("Which one starts with

question.check();

question = new TrueFalseQuestion("Which one starts with

question.check();

question = new TrueFalseQuestion("Which one is not

true?","false");

question.check();

question = new MultipleChoiceQuestion(

"What is a quiz?",

"a test of knowledge, especially a brief informal

test given to students"

"42",

"a duck",

"to get to the other side",

"To be or not to be, that is the question.",

"a");

question.check();

question = new MultipleChoiceQuestion("When is a quiz?",

"long, long ago",

"right now",

"the best of times",

"the worst of times",

"nevermore",

"b");

question.check();

question = new MultipleChoiceQuestion("Where is a quiz?", "a galaxy far, far away"

"under the sea",

"right here",

"there and back again",

"the other side of the mountain",

"c");

question.check();

question = new MultipleChoiceQuestion("Why is a quiz?",

"I think, therefore it is.",

"Who is to say?",

"You tell me.",

"Because learning is fun!",

"Because I said so.",

"d");

question.check();

question = new MultipleChoiceQuestion("How is a quiz?", "fair to middling",

"not bad",

"by a stroke of luck",

"by accident",

"Using Java object-oriented programming!",

"e");

question.check();

question.showResults();

}