Why is accessing an element of a dictionary by key O(1) even though the hash function may not be O(1)?

Question

I see how you can access your collection by key. However, the hash function itself has a lot of operations behind the scenes, doesn\'t it?

Assuming you have a nice h

Answer 1

It means that no matter what size your collection can be, it will still take almost the same amount of time to retrieve any of its members.

So in other words Dictionary with 5 members will let's say coud take around 0.002 ms to access one of them, as well as dictionary of 25 members should take something similar. Big O means algorithmic complexity over collection size instead of actual statements or functions executed