i love it

One comment said that only the last digit is allowed to be an X.. meh

I'll fix it right now*

Alright! I'll add more information about what is missing / not good!

Alright thanks for the feedback, i'll fix it right now!
The nullptr is a mistake pretty much, but keep in mind that i aim to keep this kata for C++ only, or maybe C but not in js for now.. Because of allocating an array and everything. It would be "unfair" towards say C++, since my idea was to NOT return a vector but allocate memory yourself.

Well yeah true, about an empty model, but at that point you would allocate an empty array.. might as well parse in a nullptr, you know

Hello, my idea was to just make a function which returns an allocated array of vertices and sets the amount somewhere else. Of course a vector would do the same stuff, but i think it is a good training to do it ourselves rather than stick too much to vectors.
Not that they're bad though, i used them myself in my solution. It's just an added challenge to allocate an array and stuff.

By the way, the idea came from a personal project of mine. Which is why i use a pointer instead of a vector.

honestly i'm impressed