Mastering Ruby: Strings and Encodings
https://aaronlasseigne.com/books/mastering-ruby/strings-and-encodings/
WHY STRINGS?
They’re everywhere!
As devs, you and I create tons of strings. Probably more than any other object on a day to day basis. How much do you really know about strings? How about encodings? How familiar are you with Unicode and UTF-8?