Question

I am just working on my knowledge of ArrayLists and have a question.

I have 4 classes, a person superclass, employee subclass, pupil subclass and a manager subclass of employee.

What I don’t understand is how I can use the method m.setBonus on the people ArrayList. I know I can split the objects into separate arrays but I’m not sure if that is the answer.

I am currently getting an error on the Manager m : manager part because there is no reference for manager I assume.

I currently have this code in my test class

public static void main(String[] args){

ArrayList<Person> people = new ArrayList<Person>();

people.add(new Employee("Tom", 4000, 1990, 3, 10));
people.add(new Pupil("Dick", "Comp Sci"));
people.add(new Employee("Harry", 4000, 1990, 3, 10));
people.add(new Manager ("Dan", 5000, 1990, 10, 1));

for (Manager m : manager)
{
    m.setBonus(5000);
}

for (Person p : people){

    System.out.println(p.getDetails());
}

}

}

I am sorry if this is a really simple thing. I just can’t find anything on the net.

Cheers

Answer 1

The manager arrayList does not exist, instead do the check in your existing Person loop.

public static void main(String[] args) {
    ArrayList<Person> people = new ArrayList<Person>();

    people.add(new Employee("Tom", 4000, 1990, 3, 10));
    people.add(new Pupil("Dick", "Comp Sci"));
    people.add(new Employee("Harry", 4000, 1990, 3, 10));
    people.add(new Manager ("Dan", 5000, 1990, 10, 1));

    // manager arrayList does not exist
    //for (Manager m : manager)
    //{
    //  m.setBonus(5000);
    //}


    for (Person p : people){
        //Do this instead
        if (p instanceof Manager) {
            ((Manager) p).setBonus(5000);
        }

        System.out.println(p.getDetails());
    }
}