I'm starting to learn to program. I made a code similar to this but it didn't work for me, and when I modified it according to this (Basically copied it), but I don't understand what the dots in "[...columns]" actually do? Why does it have to be there?

Fixed.

You could try selecting Node v8.1.3

(JavaScript)
This challenge is very hard to debug.
When I click "Attempt", everything that I log while my function runs is spat out in a block at the top, rather than being printed out next to its test case.
Because of this, I can't find any of the logs for my failed test cases.

Could the tests be set up differently so that logs print next to their test cases?

This is fantastic! I never would have thought to destructure the charactters in the string.

Math.floor() is used because the brief requests the answer rounded down to the nearest integer.

This Kata is a bit of a wreck.

While the challenge itself should be ranked at 7 kyu, the Module Pattern (used in the JavaScript version) may require more understanding than a 7 kyu level and is completely unnecessary for this challenge. A standard function call would have been much more practical.

On top of that, the checks for positive numbers require spaces around the "=" but the checks for 0 and for negative numbers require no spaces around their operators.

added some time ago

best solution imho

Please add sample tests.

I rather like this solution.