I often run into the case where I want to eval a query right where I declare it. This is usually because I need to iterate over it multiple times and it is expensive to compute. For example:

string raw = "...";
var lines = (from l in raw.Split('
')
             let ll = l.Trim()
             where !string.IsNullOrEmpty(ll)
             select ll).ToList();

This works fine. But if I am not going to modify the result, then I might as well call ToArray() instead of ToList().

I wonder however whether ToArray() is implemented by first calling ToList() and is therefore less memory efficient than just calling ToList().

Am I crazy? Should I just call ToArray() - safe and secure in the knowledge that the memory won't be allocated twice?