Since your super class Person doesn’t have a default constructor, in your sub classes (Student and Staff), you must call the super class constructor as the first statement.
You should define your sub class constructors like this:
Student() {
super(“a_string_value”, an_int_value);// You have to pass String and int values to super class
}
Staff() {
super(“a_string_value”, an_int_value); // You have to pass String and int values to super class
}
the first thing a constructor will do, is call the constructor (with same arguments) of the super class.
Person does not have a no-argument constructor, so, you must change your code in one of next two ways:
Student(String name, int yearOfBirth)
{
//task.
}
or
Student()
{
super(“”, 0);
//task.
}
and the same goes for Staff