Among Find, Single, First, which one is the fastest?

Question

I want to minimize the time needed to retrieve a single unique element from a list. Which one is the fastest method among Find, Single and Fi

Answer 1

They are different methods. Find is defined in List, it's almost the same as First that is defined in Enumerable.cs as an extension method on IEnumerable. Both of them will return if a conditioned item is found(no need to loop through the whole collection), so they have slight performance difference.

While Single returns the conditioned item, and also guarantees that this item is the only one that meets the condition. So in most circumstances Single is slower than First/Find because it needs to loop through the collection.