Ruby Basics Flashcards

15 flashcards covering core Ruby concepts. Tap a card to reveal the answer.

Intuition

Ruby is a language designed for developer happiness, everything is an object, and blocks/procs/lambdas make functional patterns feel natural alongside OOP. Metaprogramming is Ruby’s superpower: you can define methods at runtime, open existing classes to add methods, and use method_missing to handle calls to undefined methods. Modules provide mixins for code reuse without multiple inheritance problems.

How to Use These Flashcards

First pass: Go through all 15 cards without rating, just flip and read. This familiarises you with the content and identifies weak areas.

IRB practice: After reviewing a card, open IRB (Interactive Ruby) and experiment with the concept. Ruby’s interactive nature makes it perfect for rapid experimentation.

Rails connection: If you’re learning Ruby for Rails, relate each concept to its Rails use case, blocks for route definitions, mixins for concerns, metaprogramming for ActiveRecord.

Common Pitfalls

Monkey patching risks: Reopening a class and changing method behaviour affects every instance globally, this can introduce hard-to-debug conflicts between libraries.
Symbol vs string: :symbol and "string" differ, symbols are immutable and interned (memory efficient), strings are mutable. Use symbols for hash keys and identifiers.
Block vs proc vs lambda: Blocks are not objects, Procs don’t check argument count, and Lambdas do, mixing them up causes subtle argument-passing bugs.

Study Tips

Use IRB for rapid experimentation: Ruby’s interactive shell is perfect for testing metaprogramming techniques, exploring the object model, and verifying assumptions about method dispatch.
Read the Ruby style guide: The community style guide (rubystyle.guide) covers conventions that make Ruby code readable and maintainable. Follow it from the beginning.
Study Rails source code: Rails is a masterclass in Ruby metaprogramming. Reading how ActiveRecord defines dynamic finders or how ActiveRecord::Base uses method_missing reveals advanced techniques.
Write your own metaprogramming examples: Create a simple class that uses method_missing to delegate calls, or define methods dynamically with define_method. Hands-on experimentation builds understanding.
Practise with blocks and procs: Write functions that accept blocks using yieldconvert blocks to procs with &blockand use lambdas for strict argument checking.
Explore Ruby 3.x features: Ractors for concurrency, endless methods for brevity, and pattern matching for data destructuring are modern additions worth learning.
Study the Enumerable module: Ruby’s Enumerable mixin provides powerful iteration methods (map, select, reduce, sort_by). Understanding how to use and extend Enumerable is fundamental to idiomatic Ruby.
Practise with regular expressions: Ruby’s regex support is excellent. Write patterns for common validation tasks (email, phone, URL) and use match?, scanand gsub for string processing.

Ruby Basics Flashcards