Question

What does it mean when people write public class Nir<E> as the name of the class?

Does it mean that the instances of Nir will be collection of type E?
I don’t really get it. Is it just a declaration that the methods in the Nir will use collections?

Answer 1

E is a generic type parameter. Nir<E> is read Nir of E. It says that Nir is a class that is in some way related to E.

Collection<E> uses generics to say it contains Es.

Class<E> says it describes E.

Comparator<E> says it compares Es.

There are many uses for generics.