Convert from List into IEnumerable format

Question

IEnumerable _Book_IE
List _Book_List

How shall I do in order to convert _Book_List into IEnumerable

Answer 1

IEnumerable _Book_IE;
List _Book_List;

If it's the generic variant:

_Book_IE = _Book_List;

If you want to convert to the non-generic one:

IEnumerable ie = (IEnumerable)_Book_List;