linq to objects - set object property to null if it equals "folder"

Question

Hi,

I have a collection of objects, representing a folder structure.

I'd like to set the property "FileExtenson" to null, if its a folder.

This is as far as I've got. Can anyone help?

var items=MyClass.All().ToList();

items.ForEach(x=>x.FileExtension = string.empty).Where(y=>y.FileExtension  == "folder").ToList());

Frank

Answer 1

foreach(var item in items.Where( i => i.FileExtension == "folder" ))
    item.FileExtension = null;

Answer 2

items
  .Where(i => i.FileExtension == "folder")
  .ToList()
  .ForEach(i => i.FileExtension = null);