elyses-enchantments: please explain, in instructions, why using deleteat() returns [], but if one returns a COPY of the pruned array, Int64[]'s returned instead?

[libweirdness]

I'm not certain why this would be, obviously I'm a beginner, & Exercism's my means of learning..

The elyses-enchantments exercise..

Please explain, in the instructions, why using

deleteat!( stack_of_cards )

returns

[]

but creating a copy of the array, without deleteat(), for some reason, produces Int64[]

( Some other language I tried learning, years-ago, you had to do it that way, so I used a for-loop for the before-deletion & another for the after-deletion, in doing a copy of the array, then returned the copy, .. which failed, obviously.

It may have been Haskell )

_ /\ _

[colinleach]

deleteat!( stack_of_cards ) is not valid syntax.

The function is deleteat!( stack_of_cards, i) to remove the element at position i.

None of the tasks in this exercise needs a for loop, the vector functions are enough.

[libweirdness]

I was writing from memory, instead of flipping between tabs.

deteteat!( stack_of_cards )

without the AT, doesn't even make any functional-sense.

Obviously it wouldn't work.

---

As mentioned, my last attempts at learning this kind of stuff had been in Haskell, so the instinct that all arrays are immutable had been formed in me.

From where I was coming-from, Haskell, there is no such thing as alter-in-place arrays.

Just clarifying.

Some students are coming from such contexts.