Explain each important segment of the code.

INSTRUCTIONS: Explain each important segment of the code.

import javax.swing.JOptionPane;

public class Quiz

{

/**

* isValid accapts a string and checks to see if it is A, B, or C

* and returns a boolean value of true or false if it matches

*/

private static boolean isValid(String a)

{

a = a.toLowerCase();

if(a.equals("a") || a.equals("b") || a.equals("c") || a.equals("d"))

{

return true;

} 

else

{

JOptionPane.showMessageDialog(null, "Please pick A, B, or C");

return false;

}

}

/**

* askQuestion recieves an array containing the question and all the

* answers. Returning the user input as a String

*/

private static String askQuestion(String[] q) 

{

String fmtQuestion = ""; // String to hold the formatted question

String answer = "";

for(int i = 0; i < q.length; i++)

fmtQuestion += q[i] + "\n";

do 

{

answer = JOptionPane.showInputDialog(null, fmtQuestion);

if(answer == null)

{

int quit = JOptionPane.showConfirmDialog(null, "Would you like to quit?", "Quit", JOptionPane.YES_NO_OPTION);

if(quit == 0)

return "ABORT";

else

continue;

}

} while (answer == null || !(isValid(answer)));

return answer;

}

/**

* isCorrect recieves two values a (correct answer) and r (incorrect

* answer). Returning a boolean value if the answer is correct or not

*/

private static boolean isCorrect(String a, String r) // a = correct answer, r = user response

{

r = r.toUpperCase();

if(a.equals(r)) 

{

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

return true;

}

else

{

JOptionPane.showMessageDialog(null, "The correct answer is: \n" + a);

return false;

}

}

/**

* showGrade accepts two values c (total correct answers) and i (total

* incorrect answers). A message dialog is displayed stating the total

* coreect, incorrect, and the grade for the test

*/

public static void showGrade(int c, int i)

{

int numberQuestions = c + i;

String fmtGrade = "";

int pointsPerQuestion = 100 / numberQuestions;

int grade = c * pointsPerQuestion;

fmtGrade += "You answered " + c + " correctly and " + i + " incorrectly";

fmtGrade += "\nYour grade is: " + grade + "%";

JOptionPane.showMessageDialog(null, fmtGrade);

}

public static void main(String[] args)

{

int i = 0; // iterator to be used later for the askQuestion loop

int correct = 0; // number of correct answers

int incorrect = 0; // number of incorrect answers

String response = ""; // holds the answer the user supplied temporarily

/*

* I know multi-dimensional arrays are not till next chapter but

* I already knew about them and felt that it really was the best 

* option for this assignment

*/

JOptionPane.showMessageDialog(null, "Are you a true Potterhead?");

String[][] question = new String[10][5]; // Array to store questions

String[] correctAnswer = new String[10]; // Array to store correct answers

question[0][0] = "Who is not in Gryffindor?";

question[0][1] = "A) Harry Potter";

question[0][2] = "B) Ron Weasley";

question[0][3] = "C) Draco Malfoy";

question[0][4] = "D) Ginny Weasley";

correctAnswer[0] = "C";

question[1][0] = "Which magical creatures did Gilderoy Lockhart set loose in class?";

question[1][1] = "A) Bowtruckles";

question[1][2] = "B) Cornish Pixies";

question[1][3] = "C) Occamy";

question[1][4] = "D) Kneazle";

correctAnswer[1] = "B";

question[2][0] = "What killed Moaning Myrtle?";

question[2][1] = "A) Nagini";

question[2][2] = "B) Basilisk";

question[2][3] = "C) Occamy";

question[2][4] = "D) Boa Constrictor";

correctAnswer[2] = "B";

question[3][0] = "What Harry did to get him temporarily expelled from Hogwarts?";

question[3][1] = "A) He inflates Aunt Marge";

question[3][2] = "B) He turns Vernon into a ferret";

question[3][3] = "C) He disapparates";

question[3][4] = "D) He chases away demetors";

correctAnswer[3] = "D";

question[4][0] = "What is Slytherin's house ghost called?";

question[4][1] = "A) The Bloody Baron";

question[4][2] = "B) The Fat Friar";

question[4][3] = "C) Nearly-Headless Nick";

question[4][4] = "D) The Grey Lady";

correctAnswer[4] = "A";

(continuation of the codes in the photo below)

(continuation of the codes in the photo below)