LINQ SelectMany in Depth

The Utility Knife for Nested Collections

In this article, I’ll walk through the various overloads and usages of LINQ’s SelectMany methods.

SelectMany is in many ways the opposite of GroupBy which I covered last time in this series on LINQ. While GroupBy took a single collection and transformed it into multiple child collections, SelectMany flattens child collections into a single merged collection.

So, how is this flattening actually useful?

Basic SelectMany Operations