Averaging Grades Assignment

[Brandon Armstrong]

Hello,

I also have this same assignment to do, and I'm stuck. this is what I have currently --

I was following the above code to get some idea's on how to do it, but then I got confused.

//This program calculates and displays the grades of a student for the computer science course   
  
 
class Grades   
{   
        String studentName;   
        int testMarks = 0;   
        int midtermMark = 0;   
        int finalExam = 0;   
       
       double Basketball(String studentName, int quizMark, int midtermMark, int finalExam)   
        {   
        studentName = studentName;   
        quizMark = quizMark;   
        midtermMark = midtermMark;   
        finalExam = finalExam;   
        }   
  
                
  
        //calculate    
        String calculate()   
        {   
           double finalMark = ((finalExam * .25) + (midtermMark * .25) + (quizMark * .50));
  
            if (finalMark <= 90)   
                {   
                return letterGrade = "A";   
                }   
            if (finalMark <= 80)   
                {   
                return letterGrade = "B";   
                }   
            if (finalMark <= 70)   
                {   
                return letterGrade = "C";   
                }   
            if (finalMark <= 60)   
                {   
                return letterGrade = "D";   
                }   
            if (finalMark > 60)   
                {   
                return letterGrade = "F";   
                }   
  
            System.out.println( "Students name: " + studentName );        
            System.out.println( "Quiz Mark: " + quizMark );         
            System.out.println( "Midterm Mark: " + midtermMark );       
            System.out.println( "Final Exam Mark: " + finalExam );     
            System.out.println( "Your final overall Mark is: " + finalMark );    
        }   
  
}   
  
class GradesTester 
{   
    public static void main(String[] args)   
    {          
        
        Grades student1 = new Grades ("Joe Blow", 59, 65, 71);   
        Grades student2 = new Grades ("Frank Buttler", 85, 75, 98);   
        Grades student3 = new Grades ("Shaq O'neil", 55, 90, 86);   
        Grades student4 = new Grades ("Bill Yates", 25, 35, 44);   
        Grades student5 = new Grades ("Smart Ass", 100, 100, 100);   
  
        student1.calculate();   
        student2.calculate();   
        student3.calculate();   
        student4.calculate();   
        student5.calculate();   
    }   
}  

If someone can help me out and let me know where my error is that would be great!


Thanks in advance!

[Campbell Ritchie]

Welcome to the Ranch

I shall split your question from this thread, because your question deserves a discussion to itself.

Yes, you are stuck. Where on earth did you get that BasketBall method from?
You are getting stuck because you are doing too much all at once. Is that BasketBall thing supposed to be a constructor? If so, it must not have a return type, and its name must be exactly the same as the class. I would suggest you comment out the method completely, and leave it out until you are sure the constructor will work. You will have to comment out the 5 calculate() calls in the main() method, too

That constructor won’t work, by the way. I shall give you a little time to work out why, before letting you out of yoru misery.

For commenting out, read on:

/**
 * This method is very useful
 */
public void myMethod()
{
  someCodeOrOther();
}

/**
 * This method doesn't work and has been commented out until we work out what is wrong.
 * Always use // for commenting out.
 */
//public void myOtherMethod()
//{
//  somethingDifferentFromBefore();
//}

[Brandon Armstrong]

Tanks for the reply.

I made some changes to the code, from what I can see, everything should be working correctly...? --

//This program calculates and displays the grades of a student for the computer science course


  class Grades
{
		
		String studentName;
		int testMarks = 0;
		int midtermMark = 0;
		int finalExam = 0;
		int quizMark = 0;
	
	
		Grades(String studentName, int quizMark, int midtermMark, int finalExam)
		{
		studentName = studentName;
		quizMark = quizMark;
		midtermMark = midtermMark;
		finalExam = finalExam;
		


double finalMark = ((finalExam * .25) + (midtermMark * .25) + (quizMark * .50));

		//calculate method
	void Grades()	
	{
			
			
			if (finalMark <= 90)
				{
				return letterGrade = "A";
				}
			else if (finalMark <= 80)
				{
				return letterGrade = "B";
				}
			else if (finalMark <= 70)
				{
				return letterGrade = "C";
				}
			else if (finalMark <= 60)
				{
				return letterGrade = "D";
				}
			else if (finalMark > 60)
				{
				return letterGrade = "F";
				}

			System.out.println( "Student name: " + studentName );     
			System.out.println( "Quiz score: " + quizMark );      
			System.out.println( "Midterm Exam score: " + midtermMark );    
			System.out.println( "Final Exam score: " + finalExam );  
			System.out.println( "Your final grade is: " + finalMark ); 
		}

}

public class GradesTester 
{
	//starts program
	public static void main(String[] args)
	{		
			
		Grades student1 = new Grades ("Marcus Banks", 78, 86, 87);
		Grades student2 = new Grades ("Billy Kid", 74, 89, 78);
		Grades student3 = new Grades ("William Gates", 84, 90, 89);
		Grades student4 = new Grades ("Wilber Cumberbottom", 25, 35, 44);
		Grades student5 = new Grades ("Anita Bath", 100, 100, 100);

		student1.calculate();
		student2.calculate();
		student3.calculate();
		student4.calculate();
		student5.calculate();
	}
}
}

But now i'm getting the two following errors --

Grades.java:26: illegal start of expression
void Grades()
^
Grades.java:26: ';' expected
void Grades()
^
2 errors

[Matthew Brown]

Where does your Grades constructor end? You're missing some brackets. But once you fix that, it'll just reveal some further problems...

Your finalMark declaration needs some work as well. It should be declared outside the constructor, but initialised inside it.

Your method on line 26 - is that meant to be another constructor (it isn't) or a method (in which case it's a bad choice of name)? And why do you define is as not having a return value and then return a value?

Also - check lines 16 to 19. You're assigning variables to themselves. You need to tell the compiler which are supposed to be the constructor arguments and which are instance variables. The compiler won't guess.

I'd suggest not trying to do so much at once. Start the class simple. Add a bit, and get it to compile and work. Otherwise you can get lost like this.

[Brandon Armstrong]

Okay, did some changes again, It now will compile and run, but will only give me this as a return --

null has a Quiz score of 0.0, and a Midterm mark of 0.0, A final Exam mark of 0.0, for a final grade of 0.0
null has a Quiz score of 0.0, and a Midterm mark of 0.0, A final Exam mark of 0.0, for a final grade of 0.0
null has a Quiz score of 0.0, and a Midterm mark of 0.0, A final Exam mark of 0.0, for a final grade of 0.0
null has a Quiz score of 0.0, and a Midterm mark of 0.0, A final Exam mark of 0.0, for a final grade of 0.0
null has a Quiz score of 0.0, and a Midterm mark of 0.0, A final Exam mark of 0.0, for a final grade of 0.0

Here is the code that I changed....

//This program calculates and displays the grades of a student for the computer science course


  class Grade
{
		
		String studentName;
		int testMarks;
		int midtermMark;
		int finalExam;
		int quizMark;
	
	
		Grade(String studentName, int quizMark, int midtermMark, int finalExam)
		{
		studentName = studentName;
		quizMark = quizMark;
		midtermMark = midtermMark;
		finalExam = finalExam;
		}




		//calculate method
	void Grades()	
	{
		double finalMark = ((finalExam * .25) + (midtermMark * .25) + (quizMark * .50));	
			
			if (finalMark <= 90)
				{
				System.out.println (studentName +
                         " has a Quiz score of " + quizMark + ", and a Midterm mark of " +midtermMark +
                         ", A final Exam mark of " + finalExam + ", for a final grade of "
                          +finalMark); 	//return letterGrade = "A";
				}
			else if (finalMark <= 80)
				{
				System.out.println (studentName + " has a Quiz score of "
                        + quizMark + ", and a Midterm mark of " +midtermMark + 
                        ", A final Exam mark of " + finalExam + ", for a final grade of " 
                        +finalMark); //	return letterGrade = "B";
				}
			else if (finalMark <= 70)
				{
				System.out.println (studentName + " has a Quiz score of "
                              + quizMark + ", and a Midterm mark of " +midtermMark + ", A final Exam mark of "
                              + finalExam + ", for a final grade of " +finalMark); //	return letterGrade = "C";
				}
			else if (finalMark <= 60)
				{
				System.out.println (studentName + " has a Quiz score of " + quizMark + 
                            ", and a Midterm mark of " +midtermMark + ", A final Exam mark of " 
                            + finalExam + ", for a final grade of " +finalMark); //	return letterGrade = "D";
				}
			else if (finalMark > 60)
				{
				System.out.println (studentName + " has a Quiz score of "
                           + quizMark + ", and a Midterm mark of " +midtermMark + ", A final Exam mark of " 
                           + finalExam + ", for a final grade of " +finalMark); //	return letterGrade = "F";
				}

		}

}

public class Grades
{
	//starts program
	public static void main(String[] args)
	{		
			
		Grade student1 = new Grade ("Marcus Banks", 78, 86, 87);
		Grade student2 = new Grade ("Billy Kid", 74, 89, 78);
		Grade student3 = new Grade ("William Gates", 84, 90, 89);
		Grade student4 = new Grade ("Wilber Cumberbottom", 25, 35, 44);
		Grade student5 = new Grade ("Anita Bath", 100, 100, 100);

		student1.Grades();
		student2.Grades();
		student3.Grades();
		student4.Grades();
		student5.Grades();
	}
}

[Matthew Brown]

In that case, may I refer you the fourth paragraph of my previous answer .

[Campbell Ritchie]

I have already said that constructor would’t work

Those lines in the Grades method are too long, and I have had to insert new lines to make them legible. Don’t use tabs for indentation. That Grades() method doesn’t do what it says it does. It is doing several things, whereas a method ought to do one thing, despite what the original question said, and its name should reflect that. Grades() (apart from the capital G which is wrong) is not a helpful method name, and is close enough to the class name to cause confusion.
You ought to read the conditions in your if blocks very very carefully.
You ought to end a series of else if blocks with a plain else, and make sure that the blocks are arranged in the correct order. If the 1st block isn’t appropriate, the 2nd block should be tested and then control passes to the 3rd block if the test was false, etc., etc. The final block should be an else, which covers all cases which preceding blocks haven’t caught.

MB is right. You should be doing little bits and getting them working, rather than trying to change lots of code in the hope something will work.

[dennis deems]

In addition to the excellent advice already offered, I suggest: Break your code down into smaller, more focused tasks. The code that calculates the final mark should be separated from the code that assigns the letter grade. The code with the calls to system.out could all be consolidated into a single method that took as parameters the values that vary. These are all different tasks which will be more manageable if they are kept distinct.

[Brandon Armstrong]

Finished it....

//This program calculates and displays the grades of a student for the computer science course


  class Grade
{
		
		String studentName;
		double testMarks;
		double midtermMark;
		double finalExam;
		double quizMark;
	
	
		//calculate method
	void Grades()	
	{
		double finalMark = ((finalExam * .25) + (midtermMark * .25) + (quizMark * .50));	
			
			if (finalMark >= 90)
				{
				System.out.println (studentName + " has a Quiz score of " + quizMark + ", and a Midterm mark of " +midtermMark +
						    ", A final Exam mark of " + finalExam + ", for a final grade of: A "); 	//return letterGrade = "A";
				}
			else if (finalMark >= 80)
				{
				System.out.println (studentName + " has a Quiz score of " + quizMark + ", and a Midterm mark of " +midtermMark +
						    ", A final Exam mark of " + finalExam + ", for a final grade of: B"); //	return letterGrade = "B";
				}
			else if (finalMark >= 70)
				{
				System.out.println (studentName + " has a Quiz score of " + quizMark + ", and a Midterm mark of " +midtermMark +
						    ", A final Exam mark of " + finalExam + ", for a final grade of: C "); //	return letterGrade = "C";
				}
			else if (finalMark >= 60)
				{
				System.out.println (studentName + " has a Quiz score of " + quizMark + ", and a Midterm mark of " +midtermMark +
						    ", A final Exam mark of " + finalExam + ", for a final grade of: D"); //	return letterGrade = "D";
				}
			else if (finalMark < 60)
				{
				System.out.println (studentName + " has a Quiz score of " + quizMark + ", and a Midterm mark of " +midtermMark +
						    ", A final Exam mark of " + finalExam + ", for a final grade of: F"); //	return letterGrade = "F";
				}

		}

}



public class Grades
{
	//starts program
	public static void main(String[] args)
	{		
			
		Grade s1 = new Grade();
		s1.studentName = "Marcus Bath";
		s1.quizMark = 78;
		s1.midtermMark = 89;
		s1.finalExam = 62;
		Grade s2 = new Grade();
		s2.studentName = "Brandon Armstrong";
		s2.quizMark = 90;
		s2.midtermMark = 85;
		s2.finalExam = 55;
		Grade s3 = new Grade();
		s3.studentName = "William Gates";
		s3.quizMark = 45;
		s3.midtermMark = 32;
		s3.finalExam = 59;
		Grade s4 = new Grade();
		s4.studentName = "Billy Kid";
		s4.quizMark = 74;
		s4.midtermMark = 89;
		s4.finalExam = 78;
		Grade s5 = new Grade();
		s5.studentName = "Peter Conway";
		s5.quizMark = 100;
		s5.midtermMark = 96;
		s5.finalExam = 12;
		
		s1.Grades();
		s2.Grades();
		s3.Grades();
		s4.Grades();
		s5.Grades();
	}
}