fp.

A perfect hash function https://en.wikipedia.org/wiki/Perfect_hash_function has to be specially constructed for each desired set of inputs. Generic hash functions cannot be 'perfect'.

baruch•25m ago

It is mathematically impossible for a proper hash function (one with an output range smaller than its input range) to not have collisions. The proof uses the Pigeon Hole Principle https://en.wikipedia.org/wiki/Pigeonhole_principle

Charon77•50m ago

> Like addition

I'm perplexed to the claim that addition is cheaper than XOR, especially since addition is built upon XOR, am I missing anything? Is it javascript specific?

johanvts•18m ago

This is a excellent article for anyone looking for some more in-depth analysis of tabulation based hashing methods: https://arxiv.org/abs/1505.01523