Thank you!

The property of the object is computed.
It's like:

calcType(1,2,3) => {
    [3]: "addition",
    [-2]: "subtraction",
    [2]: "multiplication",
    [O.5]: "division"
  }

and [res] calls the equivalent property. So up here, it calls 3

Hey, what do the square brackets do in this case? Could you please explain the syntax? Thanks!

it's an ancient JediScript mind-trick

What the hell

I was wondering that myself, it seems like it isn't ranked properly if that's the case.
The kata is based on a trick more so then actual programming, which seems to defeat the point of a code kata.

Ты душный, братик... Может ты банчишь мороженым на москварике?

You hacked it! 👏

Can someone explain this sorcery?

You are supposed to write yourself all the solutions

It has nothing to do with having to write everything from scratch.

oh man i never notice such obvious things :(

You are supposed to write yourself all the solutions, in real world you can and must use other framework/libraries/utilities wrote by others in order to not reinventing the wheel, but here, you should use just your skill in programming to come to a solution

This isnt cheating imo, he went out and found a bignum. Then used it in the code he wrote. Are we supposed to rewrite every library function we use?

It works only for lowerCase letters