Getting keys from a Lookup

Question

How do I get the collection of keys from a Lookup<> I created through the .ToLookup() method?

I have a lookup which maps int-values to groups of instances of a custom class. I need a collection of all the int keys that the lookup contains. Any way to do this, or do I have to collect and save them separately?

Answer 1

You can iterate through the set of key-item groups and read off the keys, e.g.

var keys = myLookup.Select(g => g.Key).ToList();