OOP - Debugging Grimoire

🧠 Ruby OOP Crash Course – For When You’re Tired of C++’s BS

Because sometimes you want to write OOP without declaring constructors like it’s a war crime.

🎭 Classes – Your Basic Drama Unit

class Witch
  def initialize(name)
    @name = name
  end

  def cackle
    puts "#{@name} cackles wickedly. 🔮"
  end
end

sabrina = Witch.new("Sabrina")
sabrina.cackle

initialize is the constructor.
@name is an instance variable — tied to that specific girl (object).
new creates the object.
Cute and to the point.

🧘‍♀️ `self` – Finding Yourself Spiritually and Contextually

class Mirror
  def self.reflect
    puts "I am looking at myself. 💅"
  end

  def reflect
    puts "You're looking at an instance now. 👀"
  end
end

Mirror.reflect         # Class method
Mirror.new.reflect     # Instance method

self.method is a class method.
Just def method is an instance method.
You have to be explicit with self. for class methods, or Ruby’s like “nah fam”.

🫂 Instance vs Class Variables

class Cult
  @@followers = 0

  def initialize
    @@followers += 1
  end

  def self.count_followers
    @@followers
  end
end

3.times { Cult.new }
puts Cult.count_followers # 3

@@variable is shared across all instances — a class variable.
Use with caution: this can get messy if subclassing. Ruby has drama here.

📦 Modules – When You Just Wanna Mixin™ Some Behavior

module Flyable
  def fly
    puts "Zooming through the sky! 🕊️"
  end
end

class Witch
  include Flyable
end

Witch.new.fly

Use include to mixin instance methods.
Use extend to add class methods from a module.

module Sassy
  def roast
    puts "Your code's so bad, it makes Perl look readable. 💅"
  end
end

class Ruby
  extend Sassy
end

Ruby.roast

🧱 When to Use Classes vs Modules

Use Case	Go With	Why
You’re building real objects (people, dragons, buttons)	Class	They’re blueprints for things
You just want to slap on some extra behavior	Module	They’re like trait makeup kits
You’re trying to share methods across multiple classes	Module	DRY, reusable, non-instantiable
You need to instantiate something	Class	Modules don’t `.new` unless you're cursed

🪄 Inheritance – Passing Down That Magic

class Being
  def exist
    puts "I exist. 🌌"
  end
end

class Unicorn < Being
  def sparkle
    puts "✨ I sparkle with purpose ✨"
  end
end

Unicorn.new.exist
Unicorn.new.sparkle

Class < ParentClass for inheritance.
Ruby only supports single inheritance (no poly party), but you can fake it with modules.

💣 Extra Sass & Warnings

Don’t overuse class variables (@@). They can leak like gossip in a small town.
Prefer modules for reusable behavior, especially if you don’t need state.
Ruby is duck-typed — don’t obsess over class hierarchies like it’s Java.
Everything is an object. Even classes. Even nil. So go wild (but not too wild).

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