We all love Ruby, of course. One reason is the “Principle of Least Surprise”. But Ruby can still surprise us! Some are good, but some not so much.

Come follow the adventures of a (fictional) new Rubyist as she encounters Ruby's lurking gotchas, starting with basic differences from most other languages (or common sense, or common claims about Ruby), ranging to subtle ones that often catch even expert Rubyists.

This has been done before at some Washington DC area Meetups, but long ago (over a decade), and not yet at conferences.

You can see the old slides at https://bit.ly/RubyGotchas -- but my slide style has changed a lot (you can see more recent talks in my YouTube playlists of talks, at https://www.youtube.com/davearonson/playlists). Also, I intend to reformat it into the illustrated story of a new Rubyist encountering many of these gotchas (there won't be time for all of them, and many have been fixed) one by one.

At the start I breeze through some rank beginner things (like how single quoted strings don’t allow interpolation), but then progress on through intermediate gotchas (like using an object for a hash's default, making all missing references go to that same object) and then to much more advanced things in the end (like comparing procs and lambdas and what happens when you confuse one for the other).

There will certainly be code, but I don't intend to do any *live* coding.

When I first did it, I only had a couple years of Ruby under my belt, but several longtime Rubyists told me there were things in it that they didn't know about!