ASSIGNMENT: Add a class FillInQuestion1 to the question hierarchy of section 9.

Question

ASSIGNMENT:

Add a class FillInQuestion1 to the question hierarchy of section 9. Such a question is constructed witha string that contains the answer, surrounded by _ _, for example, "The inventor of java was _James Gosling_". The question should be displayed as The inventor of java was ____

CODE:

here is the Question super class (provided by book): http://notepad.cc/womeavi79

here is the FIllInQuestion1 sub class (extends Question class) that I made:  http://notepad.cc/ribiaxu25

here is the tester class that I made to test the FillInQuestion1 class: http://notepad.cc/glecotu11

When I tried to run it, the console window came up with this message in red:

Exception in thread "main" java.lang.NullPointerException

at FillInQuestion1.<init>(FillInQuestion1.java:8)

at FillInQuestionTester.main(FillInQuestionTester.java:4)

Explanation / Answer

// OUTPUT

The last month of the year is _______
Answer: December
true
The first president of the United States was _______
Answer: keka
false
3 x 5 is _______
Answer: 15
true
The capital of Texas is _______
Answer: Austin
true

//

import java.util.Scanner;
/**
   A question with a text and an answer.
*/
public class Question
{
   private String text;
   private String answer;

   /**
      Constructs a question with empty question and answer.
   */
   public Question()
   {
      text = "";
      answer = "";
   }

   /**
      Sets the question text.
      @param questionText the text of this question
   */
   public void setText(String questionText)  
   {
      text = questionText;
   }

   /**
      Sets the answer for this question.
      @param correctResponse the answer
   */
   public void setAnswer(String correctResponse)
   {
      answer = correctResponse;
   }

   /**
      Checks a given response for correctness.
      @param response the response to check
      @return true if the response was correct, false otherwise
   */
   public boolean checkAnswer(String response)
   {
      return response.equalsIgnoreCase(answer);
   }

   /**
      Displays this question.
   */
   public void display()
   {
      System.out.println(text);
   }
}

public class FillInQuestion1 extends Question {
    private String answerToQuestion;
    private String enteredText;
    private String theQuestion;
   
    public FillInQuestion1(String questionWithAnswer){
        enteredText = questionWithAnswer;
        int questionBegin = questionWithAnswer.indexOf("_");
        int questionEnd = questionWithAnswer.lastIndexOf("_");
        String questionBegin + 1);// + "___" + questionWithAnswer.substring(questionEnd);
        String>
                answerToQuestion = onlyAnswer;
                theQuestion = onlyQuestion;
        setAnswer(onlyAnswer);
        setText(onlyQuestion);
    }
    public void display(){
        System.out.println(theQuestion + "______");  
    }
    public boolean checkAnswer(String response){
        return response.equals(answerToQuestion);
    }
}


public class FillInQuestionTester {
    public static void main(String[] args){
        FillInQuestion1 FillInQuestion1("The last month of the year is _December_");
        FillInQuestion1 two = new FillInQuestion1("The first president of the United States was _George Washington_");
        FillInQuestion1 three = new FillInQuestion1("3 x 5 is _15_");
        FillInQuestion1 four = new FillInQuestion1("The capital of Texas is _Austin_");
   
        presentQuestion(one);
        presentQuestion(two);
        presentQuestion(three);
        presentQuestion(four);
    }
    public static void presentQuestion(FillInQuestion1 q){
        q.display();
        System.out.print("Answer: ");
        Scanner in = new Scanner(System.in);
        String response = in.nextLine();
        System.out.println(q.checkAnswer(response));
    }

}