Need help finishing the program that uses the class for this problem. I already

Question

Need help finishing the program that uses the class for this problem. I already have the class done and will attach it below.

_______________________________

Problem

LA teacher has five students who have taken four tests. The teacher uses the following grading scale to assign a letter grade to a student, based on the average of his or her four test scores.

Write a class that uses a String array (or an ArrayList object) to hold the five students

Explanation / Answer

//GradeBook.java
//The class is modified in getLetterGrade method.
public class GradeBook
{
   private final int NUM_STUDENTS=5;

   private final int NUM_TESTS=4;

   private String[]names=new String[NUM_STUDENTS];

   private char[]grades=new char[NUM_STUDENTS];

   private double[]scores1=new double[NUM_TESTS];
   private double[]scores2=new double[NUM_TESTS];
   private double[]scores3=new double[NUM_TESTS];
   private double[]scores4=new double[NUM_TESTS];
   private double[]scores5=new double[NUM_TESTS];
  
   public void setName(int studentNumber,String name)
   {
       names[studentNumber-1]=name;
   }

   public void setScores(int studentNumber, double[] scores)
   {
       switch(studentNumber)
       {
       case 1:copyArray(scores1,scores);break;
       case 2:copyArray(scores2,scores);break;
       case 3:copyArray(scores3,scores);break;
       case 4:copyArray(scores4,scores);break;
       case 5:copyArray(scores5,scores);break;
       default:break;
       }
   }
   public String getName(int studentNumber)
   {
       return names[studentNumber-1];
   }

   public double getAverage(int studentNumber)
   {
       double avg=0.0;
       switch(studentNumber)
       {
       case 1:avg=calcAverage(scores1);break;
       case 2:avg=calcAverage(scores2);break;
       case 3:avg=calcAverage(scores3);break;
       case 4:avg=calcAverage(scores4);break;
       case 5:avg=calcAverage(scores5);break;
       default:break;
       }
       return avg;
   }
   public char getLetterGrade(int studentNumber)
   {
       char lettergrade;
      
       //The modified code that consider only integer part because
       //the decimal points are not covered in the average in if else case
       //So type cast the average from double to integer
       //will ignore the decimal value of average
       //so that output will come as expected otherwise for Sam Young
       //79.5 average will result F grade.
       int average=(int) getAverage(studentNumber);
      
       if(average>=90&&average<=100)
           lettergrade='A';
       else if(average>=80&&average<=89)
           lettergrade='B';
       else if(average>=70&&average<=79)
           lettergrade='C';
       else if(average>=60&&average<=69)
           lettergrade='D';
       else
           lettergrade='F';
       return lettergrade;
   }

   private void copyArray(double[]to,double[]from)
   {
       System.arraycopy(from,0,to,0,from.length);
   }

   private double calcAverage(double[]scores)
   {
       double sum=0;
       for(int i=0; i<scores.length;i++)
           sum+=scores[i];

       return sum/scores.length;
   }

   public char determineGrade(double average)
   {
       char lettergrade;
       if(average>=90&&average<=100)
           lettergrade='A';
       else if(average>=80&&average<=89)
           lettergrade='B';
       else if(average>=70&&average<=79)
           lettergrade='C';
       else if(average>=60&&average<=69)
           lettergrade='D';
       else
           lettergrade='F';
       return lettergrade;
   }
   public char[]getGrades()
   {
       return grades;
   }

   public void setGrades(char[]grades)
   {
       this.grades=grades;
   }
}

----------------------------------------------------------------------------------------------------------------------------

/**
* The java program that prompts user to enter the name of the student
* and four test scores for each student and finds the letter grade
* and print the student names, average test scores and grade letter *
* */
//GradeBookDemo.java
import java.util.ArrayList;
import java.util.Scanner;
public class GradeBookDemo
{
   //create static variables
   private static final int NUM_STUDENTS=5;
   private static final int NUM_TESTS=4;  
   //create an instance orf GradeBoook class
   private static GradeBook gradeBook=new GradeBook();
   //create an array of testScore to store 4 test scores
   private static double[] testScore=new double[NUM_TESTS];
   //create an arraylist of names to store student names
   private static ArrayList<String>studentNames=new ArrayList<String>();

  
   public static void main(String[] args)
   {
      
       //create an Scanner class object to read input
       Scanner input=new Scanner(System.in);
       //create a string variable to store student name
       String name;
      
       //Read student name and test scores for five students
       for (int student = 1; student <=NUM_STUDENTS; student++)
       {
           System.out.printf("Name of Student : ");
           //prompt for the name of the student
           name=input.nextLine();
           studentNames.add(student-1, name);
           gradeBook.setName(student, name);

           //Read 4 test scores
           for (int score = 0; score < NUM_TESTS; score++)
           {

               System.out.printf("Enter score["+(score+1)+"] : ");
               //repeat prompting for test score if the testscore is less than 0 or greater than 100
               do
               {
                   //parse the string score value to double type using parseDouble method of Double class
                   testScore[score]=Double.parseDouble(input.nextLine());
                   //print a message if score is invalid
                   if(testScore[score]<0 ||testScore[score]>100)
                       System.out.println("Invalid Test Score. Enter valid score ");

               }while(testScore[score]<0 ||testScore[score]>100);

           }      
           //call the method setScores that takes student index number and array of testScores of double type
           gradeBook.setScores(student, testScore);  
           //reset name and test scores
           name="";
           for (int i = 0; i < testScore.length; i++)
               testScore[i]=0.0;
          
       }
      
       //call the method printStudentGrades to print the student names, average test scores
       //and corresponding letter grade
       printStudentGrades();
      
   }
  
  
   /*The method printStudentGrades that prints the student names, average test scores
      and corresponding letter grade. */
   public static void printStudentGrades()
   {
       for (int index = 1; index <=NUM_STUDENTS; index++)
       {
           //print name left justified with 25 character width
           //print avaerage score left justified with 10 character width and two decimal places
           //print a grade letter of 10 characters width
           System.out.printf("Name : %-25s Average Score : %-10.2f Grade : %-10c ",
                   studentNames.get(index-1),
                   gradeBook.getAverage(index),
                   gradeBook.getLetterGrade(index));
       }
   }//end of the method printStudentGrades
}//end of class GradeBookDemo

/*Note:
*The GradeBook class contains methods to get average and to find the grade letters
*finding methods. In thid demo program, the class GradeBook is used to read student
*data and set data to the GradeBook class. Then calling the getAverage and getLetterGrade
*methods to print the output as shown in the question.
* **/

----------------------------------------------------------------------------------------------------------------------------------------------------

sample output:

Name of Student : Joanne Smith
Enter score[1] : 98
Enter score[2] : 89
Enter score[3] : 100
Enter score[4] : 76
Name of Student : Will Jones
Enter score[1] : 67
Enter score[2] : 89
Enter score[3] : 91
Enter score[4] : 88
Name of Student : kerry McDonald
Enter score[1] : 78
Enter score[2] : 79
Enter score[3] : 88
Enter score[4] : 91
Name of Student : Sam young
Enter score[1] : 88
Enter score[2] : 98
Enter score[3] : 76
Enter score[4] : 56
Name of Student : Jill Barnes
Enter score[1] : 94
Enter score[2] : 93
Enter score[3] : 91
Enter score[4] : 98
Name : Joanne Smith              Average Score : 90.75      Grade : A       
Name : Will Jones                Average Score : 83.75      Grade : B       
Name : kerry McDonald            Average Score : 84.00      Grade : B       
Name : Sam young                 Average Score : 79.50      Grade : C       
Name : Jill Barnes               Average Score : 94.00      Grade : A       

Hope this helps you

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