Optimizing Lookups: Dictionary key lookups vs. Array index lookups

Question

I\'m writing a 7 card poker hand evaluator as one of my pet projects. While trying to optimize its speed (I like the challenge), I was shocked to find that the performance o

Answer 1

An array lookup is about the fastest thing you can do - essentially all it is is a single bit of pointer arithmetic to go from the start of the array to the element you wanted to find. On the other hand, the dictionary lookup is likely to be somewhat slower since it needs to do hashing and concern itself with finding the correct bucket. Although the expected runtime is also O(1) - the algorithmic constants are greater so it will be slower.