Coursera Rails Module 2 Notes
Intro to Ruby
This module goes through a general introduction to Ruby. One thing that I find interesting is how optimistic Ruby is, in the sense that everything except forfalse and nil is true. This is especially interesting from the perspective of comparing true and false in sqlite where sqlite stores 0 as false and 1 as true. I have not had to deal with this yet, but it is nice to keep in mind going forward. Another nice thing that I have not used that much is irb this is basically a Ruby repl that allows you to quickly test out concepts in your shell. I also love (since I work at a CI company) that the very first lesson about ruby talks about rspec and even has us use it go grade our assignments. It is never too early to start thinking about tests.Tour of Ruby Data Types
The next module took a nice tour of Ruby data types. I learned some pretty neat things.- Strings in Ruby super expressive, string interpolation is pretty amazing and very clean. Destructive Methods Have
!, I like this convention, you see it a lot in Clojure. - %w can make multiple strings into an array (like using .split() in JS)
- You can get a random element from an array with
.sample, pretty neat - Hash Order is maintained, this is really powerful
Object Oriented Ruby
- All methods public by default
- Clean class creation with useful helper methods for getter/setter
- Talked about how most of the functionality in Collections comes from using the Enumerator mix-in, gave an example of how to use it, super powerful!
Unit Testing
Again, I love that this course started right off the bat talking about unit testing. A+ to the course creators for covering this topic. The instructor did a good job talking about the differences between Test::Unit, MiniTest, and RSpec with great examples of how to use all of them.Assignment
The final assignment for this module was to write a program that reads a file and calculates word frequency. Overall it was pretty simple, I think the material did a good job preparing us for the task, and caused us to use a lot of the different tools that we learned about Ruby.Parting Thoughts
I have often heard that Ruby was designed for developer happiness. I really love the clean syntax, well documented API, and elegance. The next module will be a deep dive into Rails, looking forward to using more of the stuff that I have learned in this Ruby crash course.Thank you for reading! Share your thoughts with me on bluesky, mastodon, or via email.
Check out some more stuff to read down below.
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Recent Favorite Blog Posts
This is a collection of the last 8 posts that I bookmarked.
- A eulogy for Vim from Drew DeVault's blog
- Pluralistic: AI "journalists" prove that media bosses don't give a shit (11 Mar 2026) from Pluralistic: Daily links from Cory Doctorow
- Avi Alkalay: Uniqlo T-Shirt Bash Script Easter Egg from Fedora People
- Offline 23 hours a day from Derek Sivers blog
- Pluralistic: California can stop Larry Ellison from buying Warners (28 Feb 2026) from Pluralistic: Daily links from Cory Doctorow
- On Alliances from Smashing Frames
- Acting ethically in an imperfect world from Smashing Frames
- Diffusion of Responsibility from Smashing Frames
Articles from blogs I follow around the net
Changes in the system prompt between Claude Opus 4.6 and 4.7
Anthropic are the only major AI lab to publish the system prompts for their user-facing chat systems. Their system prompt archive now dates all the way back to Claude 3 in July 2024 and it's always interesting to see how the system prompt evolves as they p...
via Simon Willison's Weblog: Entries April 18, 2026You Can Message Me From My Website Now
I came across a rather interesting idea (via Intial Charge): I added a widget to every page here that lets anyone in the world immediately send me a notification. Type a message, hit send, and it’ll...
via Chris Hannah April 18, 2026Rhea Finance exploited for $18.4 million, some recovered
Rhea Finance's lending product was exploited for around $18.4 million after an attacker took advantage of a bug in the platform's slippage protection feature. The stolen assets affected both platform and user funds.Some of the stolen tokens were returned b...
via Web3 is Going Just Great April 18, 2026Generated by openring