Question

I have a little problem about my code. when i'm working on "toString method" in "Course" class, it always say there is a mistake, but i can not fix it:

Student class:

public class Student
{
   private String firstName;
   private String lastName;
   private String id;
   private boolean tuitionPaid;
  
   public Student(String firstName, String lastName, String id, boolean tuitionPaid)
   {
       this.firstName=firstName;
       this.lastName=lastName;
       this.id=id;
       this.tuitionPaid=tuitionPaid;
   }
  
   public String getFirstName()
   {
       return firstName;
   }
  
   public String getLastName()
   {
       return lastName;
   }
  
   public String getId()
   {
       return id;
   }
  
   public boolean getTuitionPaid()
   {
       return tuitionPaid;
   }
  
   public void setFirstName(String firstName)
   {
       this.firstName=firstName;
   }
  
   public void setLastName(String lastName)
   {
       this.lastName=lastName;
   }
  
   public void setId(String id)
   {
       this.id=id;
   }
  
   public void setPaid(boolean tuitionPaid)
   {
       this.tuitionPaid=tuitionPaid;
   }
     
   public void setTuitionPaid(boolean tuitionPaid)
   {
       this.tuitionPaid=tuitionPaid;
   }
  
   public String toString(String firstName, String lastName, String id, boolean tuitionPaid)
   {
       String s="Student First Name:"+firstName+"\nStudent Last Name:"+lastName+"\nStudent ID:"
               +id+"\nIs that true that this student have paid the tuition?"+tuitionPaid;
       return s;
   }

}

Course class:

import java.util.ArrayList;

public class Course
{
   private boolean getIn;
   private String name;
   private int maximum;
   private int member=0;
   private Student[] roster;
   private String[] studentInformations;
  
   public Course(String name, int maximum)
   {
       this.name=name;
       this.maximum=maximum;
       roster=new Student[maximum];
   }
  
   public void setRoster(Student[] roster)
   {
       roster=new Student[maximum];
      
       for (int i=0;i<maximum;i++)
       {
           this.roster[i]=roster[i];
           member++;
       }
      
   }

   public int getMaximum()
   {
       return maximum;
   }
  
   public Student[] getStudentRoster()
   {
       return roster;
   }
  
   public String getName()
   {
return name;
   }
  

   public void setMaximum(int maximum)
   {
   if(maximum > 0)
   {
       this.maximum = maximum;
   }
   }
  
       public void setName(String name)
       {
   this.name = name;
       }
      
   public boolean addStudent(Student student)
   {
       boolean add=false;
       if (maximum>member&&student.getTuitionPaid())
       {
           getIn=true;  
           roster[member]=student;
           member++;
           add=true;
       }else
       {
           add=false;
       }
       return add;
   }
     
   public boolean dropStudent(Student student)
   {
       boolean drop=false;
       ArrayList<String> Student=new ArrayList<String>();
      
       String information=student.toString();
      
       if(Student.contains(information))
       {
           Student.remove(information);
       }
       return drop;
   }
  
   public String toString(){
       String classInformation="Class Name: "+name+"\nSpace availiable: "+maximum;
       String register;
       if(getIn==false){
           register="\nThere is NO student in this class";
       }else{
           register="\n\tRegistered: "+member;
       }
       for(int i=0; i<maximum; i++)
       {
           studentInformations[i]=roster[i].toString();
       }
       return classInformation+getIn+studentInformations;
   }
  
}

Run CourseDriver class which test Student class and Course class:

public class CourseDriver {

public static void main(String[] args) {
      
       Student[] studentsInSchool = new Student[7];
       studentsInSchool[0] = new Student("Adam", "Ant", "S925", true);
       studentsInSchool[1] = new Student("Bob", "Barker", "S713", false);
       studentsInSchool[2] = new Student("Chevy", "Chase", "S512", true);
       studentsInSchool[3] = new Student("Doris", "Day", "S513", true);
       studentsInSchool[4] = new Student("Emilio", "Estevez", "S516", false);
       studentsInSchool[5] = new Student("Farrah", "Fawcet", "S956", true);
       studentsInSchool[6] = new Student("Greta", "Garbo", "S419", true);
      
      
       Course course = new Course("Media Studies", 5);
      
       /* note: to test the extra credit, replace the line above with the line below.
       * the rest of the program should run exactly the same.
       *
       * CourseAL course = new CourseAL("Media Studies", 5);
       *
       */
      
       System.out.println("******Testing toString: should print name, max enrollment, " +
               "and a message that the roster is empty.*****");
       System.out.println(course);

       System.out.println("******Testing add method: should add Adam, Chevy, Doris, Farrah, and Greta. " +
               "Should not add Bob or Emilio.*****");
       for(int i=0; i<studentsInSchool.length; i++) {
           Student currentStudent = studentsInSchool[i];
           if(course.addStudent(currentStudent)) {
               System.out.println(currentStudent + " added.");
           } else {
               System.out.println(currentStudent + " was not added.");
           }
       }
       System.out.println();

      
       System.out.println("******Testing toString and add methods: should print name, max enrollment, " +
               "number enrolled, and the roster.*****");
       System.out.println(course);

       System.out.println("******Testing drop and toString methods: no changes should be made when " +
               " trying to drop a student not in the course");
       course.dropStudent(studentsInSchool[4]);
       System.out.println(course);

       System.out.println("******Testing drop and toString methods: Chevy should be dropped");
       course.dropStudent(studentsInSchool[2]);
       System.out.println(course);

       System.out.println("******Testing add, drop, and toString methods: Bob should now be added " +
               " because he paid tuition and now there is room");
       studentsInSchool[1].setTuitionPaid(true);
       course.addStudent(studentsInSchool[1]);
       System.out.println(course);      
      
      

      
   }

}

Please run CourseDriver.java and check my code. Thank you very much!