> This sounds like a reasonable definition of a hash function, right? Right. > So V8 relaxes the requirement that the function be pure. getHash() then generat

> This sounds like a reasonable definition of a hash function, right? Right. > So V8 relaxes the requirement that the function be pure. getHash() then generates a random number for the object, stuffs it in some hidden chunk of memory inside the object (what the linked article is about) and declares by fiat that that number is now the hash code for that object's otherwise-intangible identity. Thanks for writing it out like that, That's exactly how I understood it, it is good to have that confirmed. I understand why that is called a hash in V8 now, but I feel exactly like ninkendo writes in a comment above: > You’d just as well call it an “equality checking code”, or name it after any other use case you could think of for a unique identifier. Ruby calls its equivalent construct “object_id” and that makes so much more sense. But your position is not wrong, this is only about what you expect to stand behind which word, and since I agree that the definition of a hash fits to that scheme this is only about connotations. Thinking of this hash as an object_id makes it clearer to me why this is done and how it could be used (and I'd absolutely use an object_id as input to a hash function, the usage does not have to differ, though that is not done here).