Ruby Object-Oriented Programming Examples

Introduction to Ruby Object-Oriented Programming

Ruby is an object-oriented programming language that emphasizes simplicity and productivity. In Ruby, everything is an object, which allows developers to model real-world scenarios effectively. This approach enhances code reusability and maintainability. Below are three diverse examples of Ruby object-oriented programming that demonstrate its capabilities.

Example 1: Creating a Simple Class for a Book

Context

This example illustrates how to create a class to represent a book in a library system. It encapsulates attributes like title, author, and availability status.

class Book
  attr_accessor :title, :author, :available

  def initialize(title, author)
    @title = title
    @author = author
    @available = true
  end

  def borrow
    if @available
      @available = false
      puts "You have borrowed '#{title}' by #{author}."
    else
      puts "Sorry, '#{title}' is currently unavailable."
    end
  end

  def return_book
    @available = true
    puts "Thank you for returning '#{title}'."
  end
end

Notes

• This class can be utilized in a library application.
• The borrow and return_book methods manage the availability of the book.

Example 2: Inheritance with Animals

Context

This example demonstrates inheritance by creating a base class for animals and extending it to create specific animal types.

class Animal
  attr_accessor :name, :species

  def initialize(name, species)
    @name = name
    @species = species
  end

  def speak
    raise NotImplementedError, 'This method should be overridden in subclasses'
  end
end

class Dog < Animal
  def speak
    "Woof!"
  end
end

class Cat < Animal
  def speak
    "Meow!"
  end
end

## Usage
my_dog = Dog.new('Buddy', 'Golden Retriever')
puts my_dog.speak  # Output: Woof!

my_cat = Cat.new('Whiskers', 'Siamese')
puts my_cat.speak  # Output: Meow!

Notes

• This example illustrates polymorphism, as different animals implement their own version of speak.
• You can extend this by adding more animal classes.

Example 3: Modules for Shared Functionality

Context

In this example, we will use modules to provide shared functionality across different classes, demonstrating Ruby’s mixin capabilities.

module Walkable
  def walk
    puts "#{@name} is walking."
  end
end

module Flyable
  def fly
    puts "#{@name} is flying."
  end
end

class Bird
  include Walkable
  include Flyable

  def initialize(name)
    @name = name
  end
end

class Dog
  include Walkable

  def initialize(name)
    @name = name
  end
end

## Usage
parrot = Bird.new('Polly')
parrot.walk  # Output: Polly is walking.
parrot.fly   # Output: Polly is flying.

rex = Dog.new('Rex')
rex.walk     # Output: Rex is walking.

Notes

• Modules allow for code reuse and organization without using inheritance.
• This promotes cleaner code and separation of concerns.