First part is quite obvious. The second one uses RegExp /rp|ps|sr/ to test concatenated string from first characters of A and B. It's pretty simple. Just read about regexp on MDN.

I am cluesless as to what is going on here? Anyone care to explain to me please? I am rather intrigued.

Your string needs to be between back-ticks, the ones situates on the left side of the keyboard. These: ``, not these ''

I know it's 4 months too late, but for you or anyone else whos interested, there's a good tutorial here: https://www.w3schools.com/python/python_lambda.asp

lambda look super powerful but I have no idea how it works. I really need to learn it tbh. Good job

My very first OOP Kata. The description was a little bit confusing at first glance, but then I facepalmed at how simple it was. Still trying to find the real world use of OOP though...

The first is inclusive, and the last is exclusive.
Description: "including the first one, excluding the last one"
So it's 50

This solution is great but works only for "example !" and not for "example!"

Currently trying to find the solution, and this talk about plateaus is melting my brain. It doesn't state clearly what one is, and its conditions.

I used 22, but I feel you 😭

I like this one