I’m not sure that I understand what you’re talking about, but the challenge wanted to remove ‘3’ from all subsequent arrays so it should return all other arrays not an empty array… is that correct?
You are misunderstanding the challenge instructions (see below).
Modify the function, using a for loop, to return a filtered version of the passed array such that any array nested within arr containing elem has been removed.
The function is called with an array of arrays. You are supposed to return an array containing only arrays which do not have a 3 in them (for this particular test case). Every sub array has the number 3 in it, so you must remove all of the sub arrays, so you are only left with an empty array.