Wow this is incredible and so beautiful. I love this!

Your solution works and it is simple, clear and easy to read. Not cheating! :)

I think it's mean to say that it "looks like !@#$". The person is attempting to learn how to code. "Best Practices" and "Clever" are definitely detrimental, however, and this type of solution should NEVER be implemented. It would be very, very slow.

The fastest and most efficient (i.e. solution that adheres to best practices) would be implementing a simple hashmap lookup table and coupling it with a simple for loop. Feel free to take a look at my solution if you are curious how this is done. It also reads perfectly fine and it is quite clear what is going on and why I chose to solve the problem in the way that I did.

On that note, using functions that require/involve a callback are also ill-advised due to performance issues. When in doubt, use a simple for loop. It is the fastest, often by quite a large margin. ES6 is not always the best way to go. ES6 can improve readability in some contexts but this comes at a high cost of performance.

I think it's mean to say that it "looks like !@#$". The person is attempting to learn how to code. "Best Practices" and "Clever" are definitely detrimental, however, and this type of solution should NEVER be implemented. It would be very, very slow.

The fastest and most efficient (i.e. solution that adheres to best practices) would be implementing a simple hashmap lookup table and coupling it with a simple for loop. Feel free to take a look at my solution if you are curious how this is done. It also reads perfectly fine and it is quite clear what is going on and why I chose to solve the problem in the way that I did.

On that note, using functions that require/involve a callback are also ill-advised due to performance issues. When in doubt, use a simple for loop. It is the fastest, often by quite a large margin. ES6 is not always the best way to go. ES6 can improve readability in some contexts but this comes at a high cost of performance.