We're playing the code golf (https://en.wikipedia.org/wiki/Code_golf) game, tl;dr write a solution with the minimal number of characters. Yes, in real, production code, you'd use const or let (var is still valid, but most modern code uses let unless var is absolutely necessary, since it has slightly different behavior https://stackoverflow.com/a/11444416/12101554), but this is still valid JavaScript.

this is considered bad practice, however

*in professional code, yes

in codegolf (crafting a solution with the fewest characters/bytes), however, anything goes

Literally just a math problem

you need to have the code inside of the curly braces { and }, not below.

This feels like a 10 kyu kata.

What's with the 1 / 0 at the end? Is it just a stylisitic thing since it won't even be ran?

the assert.strictEqual that the author uses doesn't give good error messages, what it means by "-1 should be 1" or something like that is that "you gave me a -1, but the answer i'm looking for is a 1"

Make sure you arent console.log'ging everything, i did that so i was confused of why my solution didnt work for the random tests

also, since ive done this, i can tell you that its looping from 1 to a number related to n but is larger

I don't know if user5176194 is saying that this is too hard or too easy. For me, it seems like the perfect ranking since it's easy to implement the solution and the hard part is figuring out the math you need to use to solve it.

As i said earlier,

can you give an example of code that doesnt solve this problem given any numbers, just passes all the tests?

But i'm still trying to wrap my head around how giving the completely random tests in a random assortment is better than organizing the still completely random tests into 1 input and 3 input tests