Object-oriented programming (OOP) is a programming paradigm that uses objects and their interactions to design and program applications

• Allows the program to block off areas of code that perform certain tasks independently of other areas in the application.

Encapsulation - concept of blocking off areas of code and not making it available to the rest of the program

Abstraction - is simplifying a complex process of a program, an enterprise software solution for example by modeling classes appropriate for it

Inheritance - is used where a class inherits the behavior of another class, referred to as the superclass

Polymorphism - is when a class inherits the behaviors of another class, but has the ability to not inherit everything and change some of it’s inherited behaviors. For example to write a method that does something differently from the inherited method

Classes - It is a blueprint that describes the state and behavior that the objects of the class all share. A class can be used to create many objects. Objects created at runtime from a class are called instances of that particular class.

Example of a user class

class User attr_accessor :name, :email def initialize(name, email) @name = name @email = email end def run puts "Hey I'm running" end def self.identify_yourself puts "Hey I am a class method" end end user = User.new("mashrur", "[email protected]") user.run User.identify_youself # to run this class method you don't need an instance of user