I've started having even more fun with Kotlin. One way you can learn Kotlin is by practicing and solving real exercises. That's how I discovered Exercism.org, a free way to learn dozens of languages by jumping head first into problems. One of their first exercises for learning Kotlin is calculating the Hamming Distance between DNA strands.
This made me scratch my head a few times before understanding what those double-exclamation points mean in some Kotlin code references, but it seems it's not that difficult to understand. This is another post in the "Fun with Kotlin" series. Btw, I didn't explain before because I thought it's easy to spot, I chose "Fun with Kotlin" because the word fun in Kotlin is what you start the declaration of a function with and it also means having a great time. I know, a bad dad joke but I couldn't help myself.