public void AddPeople(People newPerson)
{
foreach (var person in this.people)
{
if(newPerson is Student && person is Student)
{
var newStudent = newPerson as Student;
var student = person as Student;
if(student.UniqueClassNumber == newStudent.UniqueClassNumber)
{
throw new ArgumentException("Class numbers of students must be UNIQUE!");
}
}
}
this.people.Add(newPerson);
}
public void RemovePeople(People oldPerson)
{
this.people.Remove(oldPerson);
}