public class Lab2_Test
{
    public static void main(String[ ] args)
    {
       // uncommenting the following line should produce a compile error. 
       // This is for testing of an abstract class.
       // Person p = new Person("George");

       final int MAX_HEADCOUNT = 20;
       Person[] person_array = new Person[MAX_HEADCOUNT];

       // A student named Peter
       person_array[0] = new Student("Peter");

       // An instructor named Peter
       person_array[1] = new Instructor("Peter"); 

       // An instructor named Sandy and her salary
       person_array[2] = new Instructor("Sandy", 25000); 
	
       // A janitor named Bob
       person_array[3] = new Employee("Janitor Bob");

       // A student named Tom and his instructor is Peter.
       // The constructor needs to do three things:
       // 1: sets this student's "TeacherName" field to be "Peter",
       // 2: finds out the ID of the 1st instructor
       //    who exists in the person_array so far and named "Peter",
       //    and assign it to this student's "TeacherID" field.
       //    Set it to be 0 if no instructor named Peter is found in the person_array so far
       // 3: records this student's ID in the instructor's StudentArray if such an instructor is found
       // right after executing the following statement
       // person_array[4].TeacherID = 2
       // person_array[4].TeacherName = "Peter"
       // person_array[1].StudentArray[0] = 5
       person_array[4] = new Student("Tom", "Peter", person_array);

       // A student named Maggie and her instructor is Susan
       // right after executing the following statement
       // person_array[5].TeacherID = 0
       // person_array[5].TeacherName = "Susan"
       person_array[5] = new Student("Maggie", "Susan", person_array);

       // An instructor named Susan and her salary
       person_array[6] = new Instructor("Susan", 40000); 

       // After all objects are created,
       // instructors need to fill their students arrays,
       // and some students need to fill their TeacherIDs now,
       // since there may exist cases that when a Student object is created with instructor's name,
       // the corresponding Instructor object hasn't been created and is not in the person_array.
       // For example, person_array[6] is created after person_array[5].
       // You need to record person_array[5]'s ID in person_array[6]'s studentArray field,
       // and record person_array[6]'s ID in person_array[5]'s TeacherID field.
       // Note: if there are more than one Instructor objects
       //       having the same names as a Student object's TeacherName,
       //       it'll always be the first one's ID assigned to the Student object's TeacherID
       Instructor.findStudents(person_array);

       System.out.println("ID and name of all personnel in the array");
       for (int i = 0; i < Person.getMaxID(); i++)
       {
           System.out.println(person_array[i].getID() + ":" + person_array[i].toString());
       }
    }
}