What is the easiest way to foreach through a List removing unwanted objects?

Question

In my application, _collection is a List from which I need to remove all User objects which do not match the criteria.

However, the fol

Answer 1

_collection.RemoveAll(user => !user.IsApproved());

If you're still on 2.0:

_collection.RemoveAll(delegate(User u) { return !u.IsApproved(); });

By the way, if you don't want to touch the original list, you can get another list of approved users with:

_collection.FindAll(user => user.IsApproved());