List vs ArrayList

Question

List> listeners = new List>();

Why the line above fails with:

Cannot in

Answer 1

List cannot be instantiated, as it's just an interface.

However, you potentially have another problem as well.

Do you really have a class called 'E'? If you do, well, you shouldn't without a very good reason.

Single letters such as E and T are pretty much exclusively used to denote a generic type parameter. Read it as: "This is a general description of how to make a class or method, without any reference to any specific type - you can parameterize this class by any legal reference type".

So even classes like ArrayList<T> cannot be instantiated - because they are generic "recipes" for classes, not real concrete classes.