I think you're confounding the idea of a "dictionary" with the specific data structure of hash map/table. Not all dictionaries are hash maps. There's nothing in

I think you're confounding the idea of a "dictionary" with the specific data structure of hash map/table. Not all dictionaries are hash maps. There's nothing in the spec that says the dictionary-like properties of an object must be implemented as a hash map. I'm fairly certain that in at least V8 they are not hash maps.