Why are square brackets used? Thank you

I assume it's becuz there's no such test case for this kata.

Brilliant

Love it wish it was mine

I think it is best practice because it produced a concise and understandable solution within the constraints outlined by the problem. The problem never required specific exceptions to be caught.

simple, I like it.

This kata doesn't give you sets.

This is not best practice as you don't catch specific exceptions. This would be poor practice

don't post solutions to the dashboard, anyone can see it, and there's no need for it. i've added the spoiler flag to your comment

I wrote a recursive O(n) implementation, but I think this solution is closer to "best practice". Start with this solution, because it is simple and easy to read, understand, and maintain. If you need faster performance, and only if you need faster performance, profile your code and find the bottleneck. Finally, if this part of the code turns out to be the bottleneck, now you can implement a faster algorithm. As Donald Knuth said, "premature optimization is the root of all evil (or at least most of it) in programming".

I find there are very simple and concise solutions to problems that can be solved with lesser knowledge that is a harder code. This is a nice solution compared to the lengthy method I used with the extent of my knowledge.