Analyze and tell me how this code works.

//FlasCard class to store the Question and Answer

public class FlashCard

{

//Declare data members

private String qust;

private String ans;

// constructor of FlashCard()

public FlashCard()

{

qust = "";

ans = "";

}

// getNextQuestion() to retrieve the next question

public String getNextQuestion()

{

return qust;

}

// setNextQuestion() to set the next question

public void setNextQuestion(String qust)

{

this.qust = qust;

}

// getNextAnswer() to find the answer of the current question

public String getNextAnswer()

{

return ans;

}

// setNextAnswer() to set the answer

public void setNextAnswer(String ans)

{

this.ans = ans;

}

}

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.*;

import javax.swing.border.Border;

import javax.swing.border.EtchedBorder;

import javax.swing.border.SoftBevelBorder;

import java.io.*;

import java.util.*;

public class FlashCardGUI extends JFrame implements

ActionListener

{

//declare the required varibles

JButton response;

//To display the answer

JLabel answerDisplay;

//To hold the FlashCard object

ArrayList QuestionList;

//To set the unique questions to be displayed

ArrayList bool;

//To hold the components

JPanel card, FlashCardGame;

//To set the count of questions answered

int count = 0;

//to set the flag values

boolean flag = false;

//To hold the index of the object

int index = 0;

//To the respective values to the respective component

String welcome = "Welcome to Travis's Flash Card app!";

String start = "START THE GAME";

String nextQuestion = "Next Question";

String answer = "Click for Answer";

// constructor

public FlashCardGUI()

{

//main panel to display FlashCardGame

FlashCardGame = new JPanel(new BorderLayout());

// set border for the FlashCardGame panel

FlashCardGame.setBorder(BorderFactory.createCompoundBorder(BorderFactory.createMatteBorder(20, 20, 20,

20, Color.CYAN),BorderFactory.createRaisedSoftBevelBorder()));

//To create the QuestionList objects for the ArrayList

QuestionList = new ArrayList();

//To initialize the Boolean array list

bool = new ArrayList();

//Intitial the JPanel to hold the components

card = new JPanel(new BorderLayout());

//initialize the JButton

response = new JButton(start);

//set the Font

response.setFont(new Font("Courier New", Font.BOLD, 20));

//set the Border to the button

response.setBorder(BorderFactory.createSoftBevelBorder( SoftBevelBorder.RAISED,

Color.DARK_GRAY, Color.BLUE));

//intitialize the Label

answerDisplay = new JLabel(welcome, SwingConstants.CENTER);

//set the font for the label

answerDisplay.setFont(new Font ("Courier New", Font.BOLD + Font.ITALIC, 16));

//add the label and button to the JPanel

card.add(answerDisplay, BorderLayout.CENTER);

card.add(response, BorderLayout.SOUTH);

//add card to the FlashCardGame

FlashCardGame.add(card, BorderLayout.CENTER);

//add the FlashCardGame to the current container

add(FlashCardGame);

//Action listener to the responseButton

response.addActionListener(this);

//load the FlashCard objects from the text file

readData();

}

// getIndex() this method checks for the uniqueness of the question and then

// retrieves the index which has not been questioned

public int getIndex()

{

//declare the required varibles

int random = 0;

boolean f = false;

//loop until the boolean Values are true

while (!f)

{

//generate the random number

random = (int)(Math.random()*bool.size());

//check whether the values at the index random is

//false or not

//If false, return index

if(bool.get(random)==false)

{

f = true;

return random;

}

}

//if not found return -1;

return -1;

}

//To load the data from the file into FlashCard and add the FlashCard

//Object to the ArrayList

public void readData()

{

//define the required varibles

File file = null;

Scanner input = null;

String question, answer;

FlashCard obj = null;

//place the code inside inside the try..catch block

try

{

//intitialize the file object and scanner object

file = new File("FlashQuestions.txt");

input = new Scanner(file);

//loop until all the values are read from the text file

while (input.hasNextLine())

{

question = input.nextLine();

answer = input.nextLine();

obj = new FlashCard();

obj.setNextQuestion(question);

obj.setNextAnswer(answer);

//Add the FlashCard object to the arraylist

QuestionList.add(obj);

//To set the boolean to false

bool.add(false);

}

//close the Scanner object

input.close();

}

//catch the exception if any

catch(Exception exp)

{

exp.printStackTrace();

}

}

//JButton action event which performs the display the questions

//and answer according to the button click as specified in the question

public void actionPerformed(ActionEvent event)

{

//if the button is clicked

if (event.getSource() == response)

{

//check whethe rthe count is equal to the

//FlashCard array list size

if(count < QuestionList.size())

{

//if lesser,check for the flag values

if(!flag)

{

//if the flag is true then the display the

//question by getting the random value

index = getIndex();

//change the text of te button

response.setText(answer);

bool.set(index, true);

//display the question to the user

answerDisplay.setText(QuestionList.get(index).getNextQuestion());

}

//if the flag is false

else

{

//reset the text of the bottom to other value

response.setText(nextQuestion);

//display the answer

answerDisplay.setText(QuestionList.get(index).getNextAnswer());

//incremenet the count

count++;

}

//toggle the flag value

flag = !flag;

}

//One if all the questions are displayed,

//then to again repeat or go through the questions

else

{

int repeat = JOptionPane.showConfirmDialog(null, "Would you like to try again?",

"Confirmation", JOptionPane.YES_NO_OPTION);

//if they wanna go through the questions again

if(repeat == JOptionPane.YES_OPTION)

{

response.setText(start);

answerDisplay.setText(welcome);

count = 0;

QuestionList = new ArrayList();

bool = new ArrayList();

readData();

flag = false;

}

//else disable the button

else

{

answerDisplay.setText("Goodbye!");

response.setEnabled(false);

}

}

}

}

public static void main(String args[])

{

// create an object for the FlashCardGUI

FlashCardGUI game = new FlashCardGUI();

// set the title,

game.setTitle("Flash Card Game");

//set the size and visibility close operations

// for the JFrame

game.setSize(1000, 500);

game.setResizable(false);

game.setVisible(true);

//set the close operations for the JFrame

game.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

}