What does this code do?

Question

I'm learning c#. Most things I do understand but in this book I'm reading is this example.

abstract class GenericCustomer {
    private string name;
    public GenericCustomer() {
        name = "<no name>";
    }
    // lots of other methods
}

class Nevermore60Customer: GenericCustomer {
    private uint highCostMinutesUsed;
    // other methods etc.
}

The class is instantiated with
GenericCustomer customer = new Nevermore60Customer();

I would understand this instantiation
Nevermore60Customer customer = new Nevermore60Customer();
but I don't understand the example.

If I read it correctly it is creating an object of type GenericCustomer which is an abstract class (I didn't think you could do that) or is it a cast that creates a Nevermore60Customer but casts it as GenericCustomer (again I didn't think you could do that).

BTW I tried the code and it works. I also tried
Nevermore60Customer customer = new Nevermore60Customer();
and it works to.

Jaish Mathews · Answer

It's correct only. Here we are not creating object of "GenericCustomer ". But creating object of "Nevermore60Customer". You can see that by just put a break point in line Nevermore60Customer customer = new Nevermore60Customer(); and on executing " customer.GetType()" you can see it's "Nevermore60Customer" type. To avoid confusion remember like whish type has "new" key word that type object will be created. We have " new Nevermore60Customer(); " and thay type will be created. Below another class created like class Nevermore60Customer1 : GenericCustomer { private uint highCostMinutesUsed; // other methods etc. } and object created by GenericCustomer customer1 = new Nevermore60Customer1(); Here new Nevermore60Customer1(); used. So object type is Nevermore60Customer1 You want to undeerstand that this is the purpose of abstract calss and interfaces. A common abstract type can be instantiated with different other types.