On the forums someone is looking for a way to identify what kind of file they are dealing with. And then a way to “sort” knowing those types.
The suggestion given is to look at each extension in a simple way
But, you can get away without ever having to look at the extension. Folderitem already assigns a TYPE IF there is a filetype defined that matches.
You can use this built in ability to do many things.
I posted about this on INN along with a sample project