Question

I have a treenode collection as IEnumerable<treenode> nodes. Is there any method to create a collection of treenode.guid directly from nodes without iterating all the elements?

E.g.:

guidcollection nodeguids = nodes.somemethod();

Answer 1

The answer is not – you obviously need to iterate through the collection of nodes if you need some info from each of them. However you can do something like:

IEnumerable<Guid> nodeguids = nodes.Select(n => n.Id);

This way you do not perform an iteration manually at least. Although implementation of Select involves iteration over all the elements of the collection, and it will be done at the moment you will try to use the nodeguids collection somewhere.