Introduction to Object-Oriented Programming in Ruby

Understanding Object-Oriented Programming (OOP)

Object-Oriented Programming (OOP) is a programming paradigm that is widely used in software development. It's based on the concept of "objects," which are instances of classes, and it emphasizes data encapsulation and modularity. In Ruby, OOP is a core concept, and almost everything is an object. Let's explore OOP in Ruby step by step.

Classes and Objects

In Ruby, a class is a blueprint for creating objects. It defines the attributes (instance variables) and behaviors (methods) that the objects of the class will have. Here's an example of a simple class definition:

class Dog
def initialize(name, breed)
@name = name
@breed = breed
def bark
puts "Woof!"

In this example, we've defined a Dog class with an initialize constructor method and a bark method.

Creating Objects

To create objects from a class, you can use the new method. Objects are instances of the class and have their own set of attributes and can call methods defined in the class:

my_dog ="Fido", "Golden Retriever")

This code creates a Dog object named my_dog and invokes its bark method.

Attributes and Methods

Objects in Ruby have attributes (instance variables) that store data and methods (functions) that define their behavior. You can access and modify an object's attributes using methods:

class Dog
# ...
def name
def name=(new_name)
@name = new_name
my_dog ="Fido", "Golden Retriever")
puts = "Buddy"

In this example, we've added name and name= methods to get and set the @name attribute of a Dog object.


Object-Oriented Programming is a powerful paradigm that helps organize and structure code. In Ruby, you can easily create classes, define objects, and work with attributes and methods to build complex and modular applications.

Practice OOP in Ruby by creating your own classes and objects and exploring the principles of encapsulation, inheritance, and polymorphism. For more information, refer to the official Ruby documentation.

Happy coding!