E. G. For storage and performs reasons. 5 bytes vs 9 bytes. Multiplying by amount of users and various indexes - can produce very noticeably difference. More records per page.

So you have memory space which is reused… Which essentially makes it a mutable memory structure, where you update or add with new data keys… No?

Can you please give me an example - let’s say I have a big list of numbers and I need to find how many times each number is there.

I would expect a mutable dictionary/map and a single pass through. How would you do that without mutable datastructure?

So do you create new objects every time you need to change state?

Not even comparable