Java Programming

[SuperBowlNachos]

Anyone good at Java wanna help me out? I have literally 1 line, I think, that I need done. Just can't figure out exactly what it should be.

Driver Program(EssayDemo)...I get a syntax error at the termPaper.setScore line. I know I need to add something to the Essay class. Something using the Super command. Just not sure exactly where it goes or what it should be. We were given the first two classes. I had to build the last and that is the only one I modify.

Spoiler

public class EssayDemo
{
   public static void main(String[] args)
   {
      // Create an Essay object.
      Essay termPaper = new Essay();

      // Assign scores to the object.
      // Grammer = 25 points, Spelling = 18 points,
      // Length = 20 points, and Content = 25 points.
      termPaper.setScore(25.0, 18.0, 20.0, 25.0);

      // Display the score details.
      System.out.println("Term paper:");
      System.out.println("Grammar points: " +
                         termPaper.getGrammar());
      System.out.println("Spelling points: " +
                         termPaper.getSpelling());
      System.out.println("Length points: " +
                         termPaper.getCorrectLength());
      System.out.println("Content points: " +
                         termPaper.getContent());
      System.out.println("Total points: " +
                         termPaper.getScore());
      System.out.println("Grade: " +
                         termPaper.getGrade());
   }
}

This is the second class(GradedActivity)

Spoiler

public class GradedActivity
{
   private double score;  // Numeric score

   /**
    * The setScore method stores its argument in
    * the score field.
    */

   public void setScore(double s)
   {
      score = s;
   }

   /**
    * The getScore method returns the score field.
    */

   public double getScore()
   {
      return score;
   }

   /**
    * The getGrade method returns a letter grade  
    * determined from the score field.
    */

   public char getGrade()
   {
      char letterGrade;  // To hold the grade

      if (score >= 90)
         letterGrade = 'A';
      else if (score >= 80)
         letterGrade = 'B';
      else if (score >= 70)
         letterGrade = 'C';
      else if (score >= 60)
         letterGrade = 'D';
      else
         letterGrade = 'F';

      return letterGrade;
   }
}

This is the third class(Essay), which is extended off the one above.

Spoiler

public class Essay extends GradedActivity{
    
    private double grammar;
    private double spelling;
    private double correctLength;
    private double content;
    
  //constructors
    
  //no arg
  
    public Essay()
    {
        grammar = 0.0;
        spelling = 0.0;
        correctLength = 0.0;
        content = 0.0;
               
    }
    
    public Essay(double g, double s, double cl, double c)
    {
        grammar = g;
        spelling = s;
        correctLength = cl;
        content = c;
    }
    
    // mutators
    
    public void setGrammar(double g)
    {
        grammar = g;
    }
    public void setSpelling(double s)
    {
        spelling = s;
    }
    public void setCorrectLength(double cl)
    {
        correctLength = cl;
    }
    public void setContent(double c)
    {
        content = c;
    }

    // accessors
    
    public double getGrammar()
    {
        return grammar;
    }
    public double getSpelling()
    {
        return spelling;
    }
    public double getCorrectLength()
    {
        return correctLength;
    }
    public double getContent()
    {
        return content;
    }
    
    
    
    
            }

[stizz]

Re: Java Programming

Your calling the GradeActivity's setScore() in your main method and that only takes in one double, but you're trying to give it four.

Either, set them manually by creating the object using the second constructor with the values, by calling the appropriate methods (eg. setContent, setGrammar), or override the original setScore method in your Essay class so that it takes in four parameters.

[duffman]

Re: Java Programming

If i understand correctly you can't modify either of the first two classes you were given, just the Essay class, right? If that's the case then you would need to add a setScore(double, double, double, double) function to the Essay class. From there, you can set each individual field (grammar, spelling, etc.) inside of that function. You probably want to use the GradedActivity.setScore function to store the total score (just adding a "setScore(double);" line inside of Essay.setScore(double, double, double, double) should do it). That way when the main class calls termPaper.getScore() it will return the total score. When the main class calls each individual get() function to display the individual values they will use the code you have in your Essay class.

[duffman]

Re: Java Programming

Oh and just a quick tip about dealing with inheritance and extending class/overriding functions. If you ever start to get confused about which function call is being used (and from what class) just throw an output statement to dump out some garbage in each call in each class. Makes it real easy to track where the code is going and how if you start dealing with more complex situations since you can just follow what text got outputted and in what order.

[SuperBowlNachos]

Re: Java Programming

Uhg, still can't get this **** to work. I'm terrible at programming. I am in the required advanced class and I could not do something from the first chapter of the beginners if my life depended on it.

[stizz]

Re: Java Programming

In your Essay class, create a method named setScore which takes in 4 doubles. Then assign each parameter to the appropriate field.

So pretty much copy one of the existing setter methods, but instead of taking in 1 double and having 1 assignment statement, modify it so that it takes in 4 doubles and has 4 assignment statements.

[SuperBowlNachos]

Re: Java Programming

There should be a super somewhere in there though.

[stizz]

Re: Java Programming

Add super.setScore(grammar + spelling + correctLength + content); at the end of the method I told you to create.

[SuperBowlNachos]

Re: Java Programming

Not sure if it's right, but it works

public class Essay extends GradedActivity{
    
    private double grammar;
    private double spelling;
    private double correctLength;
    private double content;
    
  //constructors

  //no arg

    public Essay()
    {
        grammar = 0.0;
        spelling = 0.0;
        correctLength = 0.0;
        content = 0.0;        
    }
    
    
    public Essay(double g, double s, double cl, double c)
    {
        grammar = g;
        spelling = s;
        correctLength = cl;
        content = c;

    }
    
    // mutators
    public void setScore(double g, double s, double cl, double c)
    {
	setGrammar(g);
	setSpelling(s);
	setCorrectLength(cl);
	setContent(c);
    super.setScore(grammar + spelling + correctLength + content);
    }
    

    public void setGrammar(double g)
    {
        grammar = g;
    }
    public void setSpelling(double s)
    {
        spelling = s;
    }
    public void setCorrectLength(double cl)
    {
        correctLength = cl;
    }
    public void setContent(double c)
    {
        content = c;
    }



    // accessors
    
    public double getGrammar()
    {
        return grammar;
    }
    public double getSpelling()
    {
        return spelling;
    }
    public double getCorrectLength()
    {
        return correctLength;
    }
    public double getContent()
    {
        return content;
    }
    
  
            }

[SuperBowlNachos]

Re: Java Programming

Up for helping me again? I've been on a roll lately, but this one just has me staring at my screen. i think it's the days worth of plane rides I've taken the past 5 days. I just need help getting it started then I should be fine. I hope.

This is what I have to do

1. Complete Programming Challenge #1, "TestScores Class" on page 671 of the textbook.

Write a class named TestScores. The class constructor should accept an array of test scores as its argument. The class should have a method that returns the average of the test scores. If any test score in the array is negative or greater than 100, the class should throw an IllegalArgumentException. Demonstrate the class in a program.

2. One file has been provided for you, TestScoresDemo, which is partially complete. Add the appropriate code where designated in comment statements.

2a. YOU MUST CREATE THE TestScores CLASS

3. Submit the assignment via Blackboard as instructed in the course syllabus under "Lab Projects"

4. Sample Output is provide below:

Invalid score found.

Element: 3 Score: 101.0

The average of the good scores is 90.24

Spoiler

public class TestScoresDemo

{

  public static void main(String[] args)

  {

      // An array with test scores.

      // Notice that element 3 contains an invalid score.

      double[] badScores = {97.5, 66.7, 88.0, 101.0, 99.0 };

      // Another array with test scores.

      // All of these scores are good.

      double[] goodScores = {97.5, 66.7, 88.0, 100.0, 99.0 };

      // *** Create a TestScores object initialized with badScores. ***

      // ********** PLACE CODE HERE **************

      // Create a TestScores object initialized with goodScores.

      // ********** PLACE CODE HERE **************

  }

}

Spoiler

public class TestScores {

   

     

   

}