OOP in Ruby

Fundamental Concepts

• Decrease repetition
• Data and method encapsulation and hiding
• Atomic classes and functions
• Decouple classes and methods, the goal is to decrease module coupling and increasing cohesion.

The S.O.L.I.D principle

S → Separation of Concerns O → Open for extension, closed for modification L → Liskov Substitution principle I → Implement interfaces D → Decouple modules and classes

These fundamental principles of OOP extend to all languages, as they’re reflective of the paradigm and not a specific language. See my notes on OOP in this Java course, as it translates over.

Inheritance

To inherit from a class, use the syntax SubClass < SuperClass the < denotes inheritance.

Override methods

To override a method from the super class simply reimplement that class (exact same name) in the subclass.

Modules (Not OOP)

Modules can be used to bundle together functions that thematically fit together but need to be used around the project without instantiating a class instance.

Module Utils
 
	def insert_bob() do
		puts "Bob is here!"
	end
	
	def kick_jim() do
		puts "Jim was kicked!"
	end
end

To use functions in a module follow the syntax ModuleName.function()

Importing Modules into other Ruby files

Using the require keyword, we can import a module and use all its functions. The require keyword requires a file path. But there’s also require_relative that takes a relative path from the file that’s importing.