# Ruby Object-Oriented Programming (Ruby on Rails)

> Classes, modules, inheritance, mixins, attr_accessor, self, basic metaprogramming

- 20 interview questions
- Junior
- [Interview Questions: Ruby on Rails](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions.md)

## 1. How to define a class in Ruby?

**Answer**

In Ruby, a class is defined with the class keyword followed by the class name (CamelCase by convention) and ends with end. The initialize method serves as the constructor and is automatically called when creating a new instance with Class.new. Instance variables (prefixed with @) store the state of each object.

## 2. What is the role of the initialize method in Ruby?

**Answer**

The initialize method is the constructor in Ruby. It is automatically called when a new object is created via Class.new. It allows initializing instance variables and setting up the initial state of the object. Unlike other languages, the constructor is not named after the class but is always called initialize.

## 3. What is the difference between attr_reader, attr_writer and attr_accessor?

**Answer**

These three class methods automatically generate accessors. attr_reader creates only a getter (read), attr_writer creates only a setter (write), and attr_accessor creates both at once. This avoids manually writing repetitive getter/setter methods, making the code more concise and readable.

## 17 more questions available

- How does class inheritance work in Ruby?
- What is the difference between a module and a class in Ruby?

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## Other Ruby on Rails interview topics

- [Ruby Basics](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/ruby-basics.md): 25 questions, Junior
- [Rails Fundamentals](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-fundamentals.md): 18 questions, Junior
- [Routing & Controllers](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/routing-controllers.md): 22 questions, Junior
- [ActiveRecord Basics](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/active-record-basics.md): 25 questions, Junior
- [Views & ERB Templates](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/views-erb-templates.md): 20 questions, Junior
- [ActiveRecord Associations](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/active-record-associations.md): 24 questions, Mid-Level
- [Advanced ActiveRecord Queries](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/active-record-queries.md): 28 questions, Mid-Level
- [Rails Forms](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-forms.md): 20 questions, Mid-Level
- [Authentication & Authorization](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/authentication-authorization.md): 22 questions, Mid-Level
- [Modern Asset Pipeline & Frontend](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-asset-pipeline.md): 18 questions, Mid-Level
- [Rails API Mode](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-api-mode.md): 20 questions, Mid-Level
- [Testing with RSpec](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-testing-rspec.md): 24 questions, Mid-Level
- [ActiveJob & Background Jobs](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/active-job-background-jobs.md): 20 questions, Mid-Level
- [ActionCable & WebSockets](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/action-cable-websockets.md): 18 questions, Mid-Level
- [ActionMailer](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/action-mailer.md): 18 questions, Mid-Level
- [ActiveStorage](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/active-storage.md): 20 questions, Mid-Level
- [Caching Strategies](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/caching-strategies.md): 20 questions, Mid-Level
- [Advanced Migrations](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/database-migrations-advanced.md): 20 questions, Mid-Level
- [Rails Engines & Modular Apps](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-engines-modular-apps.md): 18 questions, Senior
- [Performance Optimization](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/performance-optimization.md): 26 questions, Senior
- [Rails Design Patterns](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-design-patterns.md): 22 questions, Senior
- [Ruby Metaprogramming](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/ruby-metaprogramming.md): 20 questions, Senior
- [Rails Security](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-security.md): 22 questions, Senior
- [GraphQL with Rails](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/graphql-rails.md): 20 questions, Senior
- [Deployment & Production](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-deployment-production.md): 20 questions, Senior
- [Monitoring & Logging](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/monitoring-logging.md): 20 questions, Senior
- [Rails Upgrade Strategies](https://sharpskill.dev/en/technologies/ruby-on-rails/interview-questions/rails-upgrade-strategies.md): 18 questions, Senior

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