Freely convert between List<T> and IEnumerable<T>

Question

How can I convert a List<MyObject> to an IEnumerable<MyObject> and then back again?

I want to do this in order to run a series of LINQ statements on the List, e. g. Sort()

Answer 1

List<string> myList = new List<string>();
IEnumerable<string> myEnumerable = myList;
List<string> listAgain = myEnumerable.ToList();