Fixed.

I have no idea with recursion solution :) But your & my code working fine with big n :)

You are absolutely right, sir.
First time ever I see that recursion is actually not a clever thing to do.

Is it still somehow possible to run this code with n = 100? Mine returns "Interupt" error.

That is Bad Practice! What about if n == 100? :) Your program will kill itself.

I got also the problem of randomness making the test crash sometimes.
As for the NaN, it's not a finite number

Nothing can be changed after 500+ solutions have passed.

The tests are randomly generated. It makes kata pass sometimes (and sometimes no). As well the directions don't say what to do when NaN is passed (JS).

Thanks!
I also found this useful for anyone newer

https://www.youtube.com/watch?v=zg-ddPbzcKM

This is an example of recursion. The concept is present in many programming languages, and mathematics in general.

The equation for a single fibonacci number is dependent on the two previous fibonacci numbers (for all but n == 1 && n == 2). These are determined by either:

• Calling the fibonacci method again from within the fibonacci method itself (which may in turn call itself many more times, until it hits a seed value).
• Hitting an n value that acts as a seed. These seed values are required to prevent infinite recursion, and are implemented as the following lines in this solution:

return 0 if n == 1
return 1 if n == 2

For a ruby specific explanation of recursion, check out this StackOverflow Post.

For a more broad, mathematical explanation (including fibonacci numbers) see the wiki article on Recurrence relations.

Can someone explain how this works?
Newer to ruby and don't understand this method with a method call...?

nth_fibonacci(n-1)+nth_fibonacci(n-2)