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Question: Course grades java class In a course, a teacher gives the following tests and assignments: A lab ...

course grades java class

In a course, a teacher gives the following tests and assignments:

A lab activity that is observed by the teacher and assigned a numeric score.

A pass/fail exam that has 10 questions. The minimum passing score is 70.

An essay that is assigned a numeric score.

A final exam that has 50 questions.

Write a class named CourseGrades. The class should have a GradedActivity array named grades as a field. The array should have four elements, one for each of the assignments previously described. The class should have the following methds:

setLab: This method should accept a GradedActivity object as its argument. This object should already hold the student’s score for the lab activity. Element 0 of the grade field should reference this object.

setPassFailExam: The method should accept a PassFailExam object as its argument. This object should already hold the student’s score for the pass/fail exam. Element 1 of the grades field should reference this object.

setEssay: This method should accept an Essay object as its argument (See Programming Challenge 4 for the Essay class). This object should already hold the student’s score for the essay. Element 2 of the grades field should reference this object.

setFinalExam: This method should accept a FinalExam object as its argument. This object should already hold the student’s score for the final exam. Element 3 of the grades field should reference this object.

toString: This method should return a string that contains the numeric scores and grades for each element in the grades array.

The code I found on Chegg's is this but I get it to work because on line is wrong can someone help me please:

import java.util.Scanner;

public class CourseGrades

{

public static void main(String[] args)

{

int grades,FinalExam,essay,PassFailExam,GradedActivity;                 

GradedActivity.grades[],[] = new int grades.grades[4];  

grades[0] = new grades();

grades[0].setLab(95);

grades[1] = new PassFailExam(10, 3, 70);

grades[2] = new grades();

grades[2].essay(95);

grades[3] = new FinalExam(50);

for (int index = 0; index < grades.length; index++);        

class GradedActivity

{

private double score;

   public void setLab(double s)

{

score = s;

}

public double getLab()

{

return score;

}

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;

}

}

}

}

Answer 1

import java.util.*;

class GradedActivity
{
   private double score;
   public void setScore(double s){
       score =s;
    }
  
   public double getScore(){
      return score;    
   }
  
   public char getGrade(){
       char grade;
      
       if (score >= 90)
           grade = 'A';
          
       else if (score >= 80)
           grade = 'B';
      
       else if (score >= 70)
           grade = 'C';
          
       else if (score >= 60)
           grade = 'D';
          
       else
           grade = 'F';
         
           return grade;
   }   
}
class LabActivity extends GradedActivity
{

public LabActivity(double x)
{
      setScore(x); // pass score to base class to display score and grade
    }
   
   

}
class PassFailExam extends GradedActivity
{
  
    public PassFailExam(double x)
    {
        setScore(x);// pass score to base class to display score and grade
    }
   
}
class Essay extends GradedActivity
{

public Essay(double x)
    {
        setScore(x);// pass score to base class to display score and grade
    }
  
}

class FinalExam extends GradedActivity
{
  
public FinalExam(double x)
    {
        setScore(x);// pass score to base class to display score and grade
    }
   
}

class CourseGrades
{
    private GradedActivity[] grades = new GradedActivity[4];
    double score;
    public void setLab(LabActivity la)
    {
        grades[0]=la;
     }
    
    public void setPassFailExam(PassFailExam pfe)
     {
      grades[1]=pfe;
     }
    
    public void setEssay(Essay e)
     {
      grades[2]=e;    
     }
    
    public void setFinalExam(FinalExam fe)
    {
       grades[3]=fe;
    }
   
    public String toString()
     {
         LabActivity la=(LabActivity)grades[0];
         PassFailExam pfe=(PassFailExam)grades[1];
         Essay e=(Essay)grades[2];
         FinalExam fe=(FinalExam)grades[3];
        
        
          String temp= "Lab Activity:\n"
                      + " Score: " + grades[0].getScore()
                      + " Grade: " + grades[0].getGrade()
                     
                      + "\nPassFailExam Score:\n"
                      + " Score: " + grades[1].getScore()
                      + " Grade: " + grades[1].getGrade()
                     
                      + "\nEssay score:\n"
                      + " Score: " + grades[2].getScore()
                      + " Grade: " + grades[2].getGrade()
                     
                      + "\nFinalExam score:\n"
                      + " Score: " + grades[3].getScore()
                      + " Grade: " + grades[3].getGrade();
             return temp;
     }

}

class CourseGradeDemo
{
public static void main(String arg[])
{
double score;
Scanner input=new Scanner(System.in);

   System.out.println("Enter the score for lab activity:");
   score=input.nextInt();
   LabActivity la= new LabActivity (score);

System.out.println("Enter the score for pass/fail exam activity:");
score=input.nextInt();
PassFailExam pfe=new PassFailExam(score);

System.out.println("Enter the score for Essay activity:");
score=input.nextInt();
Essay e=new Essay(score);

System.out.println("Enter the score for final exam activity:");
score=input.nextInt();
FinalExam fe=new FinalExam(score);

CourseGrades cg=new CourseGrades();
          cg.setLab(la);
          cg.setPassFailExam(pfe);
          cg.setFinalExam(fe);
          cg.setEssay(e);
         
          System.out.println(cg.toString());
         
        }
    }

Output:

Enter the score for lab activity:80
Enter the score for pass/fail exam activity:78
Enter the score for Essay activity:54
Enter the score for final exam activity:66
Lab Activity:
Score: 80.0 Grade: B
PassFailExam Score:
Score: 78.0 Grade: C
Essay score:
Score: 54.0 Grade: F
FinalExam score:
Score: 66.0 Grade: D

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