Common Ruby on Rails Interview Questions and Answers

To secure a job successfully, excelling in your interview is essential. If you’re vying for a position that involves Ruby on Rails, it’s crucial to demonstrate your skills and qualifications by effectively addressing a range of pertinent questions posed by the hiring manager.

If you’re in line for a role that involves utilizing the Ruby on Rails web application framework, it’s advisable to get ready by anticipating the questions likely to be posed. Below are some questions along with sample answers to help you prepare.

1. What is Ruby on Rails?

Ruby on Rails, commonly referred to as Rails, stands as a server-side web application development framework scripted in the Ruby programming language. Developed by David Heinemeier Hansson under the MIT License, Rails embraces the MVC (Model-View-Controller) architecture, offering a predefined structure for databases, web pages, and web services. It leverages web standards such as JSON or XML for data transfer and utilizes HTML, CSS, and JavaScript for crafting the user interface. Emphasizing the incorporation of established software engineering patterns and paradigms, Rails is designed to promote efficient and organized web application development.

A) DRY (Don’t Repeat Yourself): This is a fundamental principle in software development aimed at minimizing the redundancy of information or code.

B) CoC (Convention Over Configuration): This principle advocates for providing predefined conventions for the optimal way to handle various aspects within a web application.

2. Why use Ruby on Rails?

• Accelerates the deployment of responsive web applications.
• Cost-effective solution through the utilization of the Ruby on Rails framework.
• Simplifies maintenance and mitigates issues related to data migration.
• Enhances the speed and security of our application with the Ruby on Rails Framework.
• Seamless integration of the latest functionalities for easy application updates.
• Employs Metaprogramming techniques for efficient program development.

3. Tell the Name of things Rails Migration can do.
Rails Migration offers a wide range of capabilities, such as table renaming, column addition, column modification, table deletion, column removal, and more.
4. How can you protect Rails against Cross-Site Request Forgery?
Rails provides the feature CSRF token to protect Cross-Site-Forgery, to implement it we have to write ‘protect_from_forgery‘ in relevant controller.
5. What the use of garbage collection in Ruby On Rails?
Garbage collection helps prevent memory leaks by identifying and releasing memory occupied by objects that are no longer needed. This ensures efficient utilization of memory resources within a Rails application.
Automatic Resource Reclamation, Improved Performance, Preventing Memory Exhaustion, Enhancing Developer Productivity
In summary, garbage collection in Ruby on Rails is a vital mechanism that ensures efficient memory usage, prevents memory leaks, and contributes to the overall reliability and performance of web applications built on the Rails framework.
6. What are the some limitations on Ruby On Rails?

While Ruby on Rails is a powerful and flexible web development framework, it does have some limitations. Here are a few notable ones:

Learning Curve: For developers who are new to Ruby on Rails, there can be a learning curve. The framework has its conventions and best practices, and understanding them might take time, especially for those not familiar with Ruby.

Performance: While Rails has improved its performance over the years, it might not be as fast as some lower-level, more lightweight frameworks, especially for certain types of applications. However, efforts have been made to address this through optimizations and the use of caching strategies.

Opinionated Framework: Rails is an opinionated framework, which means it enforces certain conventions and makes decisions for the developer. While this can speed up development by reducing decision-making, it may not be suitable for projects with specific architectural requirements that deviate significantly from Rails conventions.

Community Size: While the Ruby on Rails community is vibrant and supportive, it might not be as extensive as some other larger communities associated with different programming languages and frameworks.

7. What are the basic types of variables used in Ruby class?

In Ruby, variables in a class can be categorized into several types based on their scope and usage. Here are the basic types of variables used in a Ruby class:

Local Variables:

• Scope: Limited to the block or method where they are defined.
• Naming Convention: Starts with a lowercase letter or an underscore (_).

Instance Variables:

• Scope: Belongs to an instance of a class and is accessible throughout the entire class.
• Naming Convention: Starts with @.

Class Variables:

• Scope: Belongs to the class and is shared among all instances of that class.
• Naming Convention: Starts with @@.

Global Variables:

• Scope: Available throughout the entire Ruby program.
• Naming Convention: Starts with $.

These variable types provide different levels of scope and visibility within a Ruby class, allowing developers to control the accessibility and lifespan of data in their programs. It’s important to use them judiciously based on the specific requirements of the code.

8. Explain the difference between a class and an instance of a class in Ruby.

In Ruby, a class and an instance of a class are fundamental concepts in object-oriented programming. Let’s explore the key differences between a class and an instance:

1. Class:
   • Definition: A class is a blueprint or a template for creating objects. It defines a set of attributes and behaviors that its instances will have.
   • Purpose: Classes encapsulate related data and functionality, allowing you to create objects with similar characteristics and behaviors.
2. Instance:
   • Definition: An instance, or object, is a concrete realization of a class. It is created from a class and represents a specific occurrence of that class.
   • Purpose: Instances hold unique data and can invoke the behaviors defined in their class. They are individual entities with their own state and behavior.