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

Please see post What does "O(1) access time" mean?

The number of operations in a hash function is irrelevant as long as it takes the same (constant) amount of time for EVERY element in the collection. For example, accessing one element in a collection of 2 elements takes .001 ms, but also accessing one element in a collection of 2,000,000,000 elements takes .001 ms. Although the hash function can contain hundreds of if statements and multiple calculations.