Filtering collections in C#

c#, collections, filtering

Solution

If you're using C# 3.0 you can use linq, which is way better and way more elegant:

List<int> myList = GetListOfIntsFromSomewhere();

// This will filter ints that are not > 7 out of the list; Where returns an
// IEnumerable<T>, so call ToList to convert back to a List<T>.
List<int> filteredList = myList.Where(x => x > 7).ToList();

If you can't find the `.Where`, that means you need to import `using System.Linq;` at the top of your file.

Problem

I am looking for a very fast way to filter down a collection in C#. I am currently using generic `List<object>` collections, but am open to using other structures if they perform better. Currently, I am just creating a new `List<object>` and looping thru the original list. If the filtering criteria matches, I put a copy into the new list. Is there a better way to do this? Is there a way to filter in place so there is no temporary list required?

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