Why collections classes in C# (like ArrayList) inherit from multiple interfaces if one of these interfaces inherits from the remaining?

Question

When I press f12 on the ArrayList keyword to go to metadata generated from vs2008, I found that the generated class declaration as follows

public class Array         


        

Answer 1

The extra interfaces are shown because they are implied by IList. If you implement IList, you must also implement ICollection and IEnumerable.