Why does GetDirectoryName return null for C:\?

Question

I just came across what seems like a weird design choice:

System.IO.Path.GetDirectoryName(@"C:\folder\file.ext")

returns "C:\folder"

but

System.IO.Path.GetDirectoryName(@"C:\")

returns null.

I could understand it better if the first example returned "folder".

Any ideas why this is the case? And what do you do when you just want to get the folder path?

Answer 1

Actually the function would have been better named GetPathName. it returns the full path of the directory of the filename you passed.