Updated June 15, 2023
Ruby Interview Questions and Answers
Ruby is a dynamic, open-source programming language focusing on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write. Ruby is a language of careful balance. Ruby is a pure object-oriented programming language. Ruby is simple in appearance but is very complex inside, just like our human body. In Ruby, everything is an object.
Below is the list of the top 2023 Ruby Interview Questions and Answers:
Part 1 – Ruby Interview Questions (Basic)
This first part covers basic Ruby Interview Questions and Answers:
Q1. How will you define Ruby’s programming language?
Answer:
Ruby is a dynamic, reflective, general-purpose, open-source programming language focusing on simplicity and productivity. Ruby is a pure object-oriented programming language with simple in appearance and complex inside.
Q2. Can you explain the different features of the Ruby Programming Language?
Answer:
Below is the list of features offered by Ruby:
- Ruby is open-source and is freely available on the Web.
- Ruby is a general-purpose and interpreted programming language.
- Ruby is a true object-oriented programming language.
- Ruby is a server-side scripting language that is very much similar to Python and PERL.
- Ruby can be used to write Common Gateway Interface (CGI) scripts.
- Ruby can be embedded into Hypertext Markup Language (HTML).
- Ruby has a clean and easy syntax that allows a new developer to learn very quickly and easily.
- Ruby has a syntax similar to that of many programming languages, such as C++ and Perl.
Q3. What are the different Ruby editors?
Answer:
Below are different editors for Linux and Windows:
- You can use Notepad or Edit Plus on Windows.
- You can use VIM on Linux.
- RubyWin is a Ruby Integrated Development Environment (IDE) for Windows.
- Ruby Development Environment IDE for Windows users.
Q4. What is the difference between raise/rescue and throw/catch in ruby?
Answer:
Raise and rescue is used to raise and handle exceptions which are often used for exception handling, whereas throw and catch accept only matching symbols as arguments and are considered as a control-flow structure and not used for exception handling in common. Raise and Rescue is the fundamental part of the Ruby language.
Q5. What are Ruby variables, and explain each?
Answer:
There are four types of variables in Ruby:
- Global Variables: These variables start with $, and their scope is available for the entire Ruby program.
- Class Variables: These variables start with @@ and are accessible by all instances of the class that is defined.
- Local Variable: These variables start with a lowercase letter or an underscore, and the scope is within the function or code construct where it is declared.
- Instance Variable: These variables start with @ and are similar to class variables, except class variables are local to a single class instance.
Q6. What are the different variables in Ruby?
Answer:
Ruby has four types of variables:
- Local Variables: Local variables are the variables that are defined in a method. Local variables are not available outside the method.
- Instance Variables: Instance variables are available across methods for any particular instance or object. That means that instance variables change from object to object.
- Class Variables: Class variables are available across different objects. A class variable belongs to the class and is a characteristic of a class.
- Global Variables: Class variables are not available across classes. If you want to have a single variable available across classes, you need to define a global variable.
Q7. What is the command to get the installed Ruby version in your system?
Answer:
The command to get the installed Ruby version in your system is Ruby –v.
Q8. What are the advantages of using Ruby?
Answer:
- Ruby is an open-source language, 100 percent free, with a large developer community.
- Ruby is well-suited for Metaprogramming, it provides the ability to write code that depends on other code.
- Ruby has simple and easy syntax; users can develop complex programs within in few lines of code. The code is human-readable and easy to follow and understand.
Q9. What are the different operators used in Ruby?
Answer:
The different operators in Ruby are:
- Unary operator
- Arithmetic operator
- Bitwise operator
- Logical operator
- Ternary operator
Q10. What is the difference between a statement and an expression in Ruby?
Answer:
In Ruby, all statements are expressions; every statement will return a value. A statement is a simple way to refer to any syntax.
Q11. Why use “each” instead of “For/in” Ruby?
Answer:
It all depends on the ruby; it is a ruby’s way. It shows how Ruby defines methods that mimic/ exact copy of natural language concepts. #each is an iterator method that reads more naturally and is a block that defines the new variable scope, whereas #for/it depends on the existence of #each, which means #each is a fundamental part of natural language. So in ruby #, each is used instead of #for/in.
Q12. What are the different class libraries used in Ruby?
Answer:
The different class libraries used in Ruby are:
- Text processing
- CGI Programming
- Network programming
- GUI programming
- XML Programming
Q13. What are the different data types used in Ruby?
Answer:
The different data types used in Ruby are:
- Numbers
- Strings
- Symbols
- Hashes
- Arrays
- Booleans
Part 2 –Ruby Interview Questions (Advanced)
Let us now have a look at the advanced Ruby Interview Questions:
Q14. What are the different iterators used in Ruby?
Answer:
The different iterators used in Ruby are:
- each iterator
- times iterator
- upto and down to the iterator
- step iterator
- each_line iterator
Q15. What is the use of Super?
Answer:
Super has the following forms of implementation.
- Calling only the super means
- Call the parents to initialize
Q16. Describe the method name resolution process in Ruby
Answer:
Below are the steps to follow for method name resolution:
- First, we need to check the eigenclass for singleton methods, including the inheritance of eigenclasses on class objects.
- Next, we need to check for instance methods and instance methods for any included modules.
- Next, we need to check instance methods and instance methods for any included modules in an inheritance hierarchy manner.
Q17. Explain the role of thread pooling with respect to the thread lifecycle in Ruby.
Answer:
In Ruby, the lifecycle of a thread starts automatically whenever CPU resources are available. Threads will work by using CPU resources but running multiple threads at a time will improve application performance.
These threads will be ready to perform tasks whenever needed.
Q18. What is the difference between Block, Proc, and Lambda in Ruby?
Answer:
In General, calling lambda is similar to invoking a method where a return statement will be returned. Lambda must be invoked with an exact number of arguments, whereas procs are flexible in handling arguments. These are the advanced Ruby Interview Questions which is asked in an interview.
Q19. How can you declare a block in Ruby?
Answer:
In Ruby, the code in the block is always enclosed within braces ({}). You can invoke a block by using a yield statement.
Q20. What are the levels of method access control for classes in Ruby?
Answer:
There are three levels of method access control for classes:
- Public Methods: It can be called by all objects and subclasses of the class in which they are defined in.
- Protected Methods: It can be only accessible to objects within the same class.
- Private Methods: It is accessible in the same instance.
Q21. How does the symbol differ from the string?
Answer:
- Multiple symbols representing a single value are identical, which is impossible with the Strings.
- Symbols and strings are used interchangeably by various developers, and You can consider Symbols as faster & immutable strings.
Q22. What is an interpolation in Ruby Programming Language?
Answer:
Interpolation is a very important process in Ruby. Interpolation is the process of inserting a string into a literal. There is only one way in which you can interpolate a string into a literal by placing a Hash (#) within {} open and close brackets. This refers to a new name by referring to the copy of the original method.
Q23. What is the difference between calling super and super() in Ruby?
Answer:
In Ruby, calling super invokes the parent method with the same arguments as passed to the child method. If arguments passed to the child, don’t match what the parent is expecting, then an error will be thrown.
In Ruby, calling super () invokes the parent method without any arguments, as expected. As always, being explicit in code is good.
Q24. What is the difference between nil and false in Ruby?
Answer:
- In Ruby, nil cannot be a value, whereas false can be a value.
- Nil is not a Boolean data type, whereas false is a Boolean data type.
- Nil is an object of the nil class, whereas false is an object of a false class.
Q25. What is the difference between NIL and FALSE in Ruby?
Answer:
The differences between NIL and FALSE in Ruby are:
- FALSE is a boolean data type, whereas NIL is not.
- NIL cannot be a value, whereas FALSE can be a value.
- A method returns true or FALSE in the case of a predicate.
- NIL is an object for NilClass, whereas FALSE is an object for FalseClass.
Recommended Articles
This has been a guide to the List of Ruby Interview Questions. Here we have covered the few commonly asked interview questions with their detailed answers so that candidates can crack interviews with ease. You may also look at the following articles to learn more –
