Top 20 most asked Ruby Interview Questions for freshers

Top 20 most asked Ruby Interview Questions for freshers .Ruby is an object-oriented, dynamic programming language that prioritizes efficiency and ease of use. It is well-known for its simple syntax that is sometimes referred to as “natural-language-like.” This makes it reasonably simple to grasp and learn, especially for people who are not familiar with programming.

Ruby is a flexible language that can be used for many different tasks, such as automation, data analysis, scripting, and web development. It’s especially well-liked for web development frameworks like Ruby on Rails, which make web application development easier.

Here are some Top 20 most asked Ruby Interview Questions for freshers

1.Explain Ruby if-else statement.

Ruby’s if-else statement is a conditional statement that lets you run various code blocks according to a specified circumstance. It’s an essential control flow structure that facilitates decision-making and the development of more dynamic systems.

• Condition: The term “if” is used at the beginning of the if statement, followed by a condition. An expression that evaluates to true or false is used in this condition. The code block contained in the if statement is executed if the condition is true.
• Else: Optionally, you can include an else clause after the if statement. The else clause contains a code block that is executed if the condition is false. This provides a way to handle alternative scenarios or default behaviour.

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2.Explain case statement in Ruby.

The case statement is a strong and adaptable conditional execution technique in Ruby. It offers a clearer and more accessible substitute for nested if-else expressions, particularly when handling several situations.

A case statement’s fundamental structure consists of an expression to be evaluated and a case keyword. Next, this expression is evaluated against a number of when clauses. The relevant code block is performed if the expression in a when clause matches. The else clause, if it exists, is carried out if no match is discovered.

3. Explain for loop in Ruby.

The for loop is mostly used in Ruby to iterate over a group of elements, like an array or a range. It offers a clear and understandable method for carrying out operations on every component of the collection.

The for keyword, a variable name, the in keyword, and an expression that represents the collection to iterate over make up the fundamental building blocks of a for loop. Every time an iteration, the current element is assigned to the variable name, which enables you to manipulate it within the body of the loop.

4. Explain next stateAment in Ruby.

Within loops (such as for, while, or do-end), the following statement is used to move on to the next iteration without running any of the remaining code in the current iteration. This is very helpful if you wish to exclude specific situations or elements based on predetermined standards.

Use next to go on to the next element, for instance, if you’re iterating over an array and come across a value that satisfies a particular requirement. By doing so, you can reduce the number of pointless computations and increase the efficiency of your code.

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5. Explain Ruby object.

Everything is an object in Ruby, including complicated structures like arrays and hashes and basic data types like strings and integers. In Ruby programming, objects serve as a key building block for creating and manipulating data since they encompass both data (attributes) and behavior (methods).

Every object is a member of a class, which specifies the properties and functions that members of that class are allowed to have. The class keyword can be used to build classes, and the new method can be used to instantiate instances. Via method calls, objects can communicate with one another and exhibit dynamic, complicated behavior.

6.What is the difference between String and Symbol?

In Ruby, strings and symbols are both used to represent text data, but they serve different purposes and have distinct characteristics.

Strings : are changeable character sequences that are surrounded by single or double quote marks. They can be changed, combined, and worked with in many ways. Textual data is frequently stored and displayed using strings.

Symbols : conversely, are unchangeable items that serve as unique identifiers. They are made by placing a colon (:name) after the name of the identifier. Because symbols are not meant to be changed, Ruby effectively controls memory by making sure that a symbol is only used once.

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7.Explain how rail implements Ajax?

AJAX implementation is made easier with Rails by utilizing its convention-over-configuration philosophy. The JavaScript code required by Rails to handle the asynchronous request is automatically generated when you mark a form or link with the remote: true property.

Rails intercepts the request made by clicking the link or submitting the form, and it is sent as an AJAX request to the server. The matching controller action is called on the server, and the response—typically JSON or HTML—is provided in a format that is compatible with JavaScript. Without requiring a complete page reload, the created JavaScript then updates the designated area of the page with the received response, resulting in a dynamic and interactive user experience.

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8. What does garbage collection do in Ruby on Rails?

In Ruby on Rails, garbage collection is a process that takes care of memory allocation and deallocation for objects automatically. The garbage collector recognizes items and recovers the memory they occupy when they are no longer required or referenced by other objects. This procedure guarantees that memory is used efficiently in Rails apps and helps to minimize memory leaks.

The mark-and-sweep mechanism is used by Ruby’s garbage collector to identify items that are still in use. After marking every object that can be accessed from the object graph’s root, it goes through the memory and retrieves any unmarked objects. You can use configuration parameters to control garbage collection’s frequency and intensity, but in most cases, the Ruby runtime takes care of it automatically.

9. What are access modifiers in Ruby?

The visibility of methods and instance variables within a class is managed using access modifiers in Ruby. Ruby has a convention-based method to determine visibility, unlike several other languages that have explicit private or public keywords.

Public : Instance variables and public methods are available from anywhere, inside and outside of the class. Unless specifically stated otherwise, all Ruby methods and instance variables are public by default.

Private : Private methods can only be accessed from other methods specified in the same class or from within the class itself. This encourages encapsulation and avoids unexpected side effects by making sure that certain methods are not used directly from outside the class.

Protected : Both the class and its subclasses have access to protected methods. This limits subclasses’ access to the class hierarchy while enabling them to inherit and override certain methods.

10. What is the role of load and require in Ruby?

load and require in Ruby: Importing Code

You can reuse code modules in different sections of your program by using load and require to import external Ruby code files into the current execution context. But they exhibit different behaviors:

Each time load is encountered, the specified file is loaded. This implies that the code included in a file will be performed more than once if it is loaded numerous times during a single execution. This can be helpful for modules that need to be run more than once or for dynamic code reloading.

even if a file is encountered more than once during a single operation, it only needs to be loaded once. Ruby does this by remembering the files it has loaded and not loading them again. For importing code modules, this is usually the best approach because it reduces the chance of duplicate execution and boosts efficiency.

11.How would you freeze an object in Ruby?

In Ruby, freezing an object stops future changes to its state. This implies that you are unable to call methods that alter its internal data or modify its properties. An thing stays frozen for the rest of its existence once it has reached that state.

12.Explain DRY in Rails?

DRY (Don’t Repeat Yourself) is a basic idea in software development that strives to make code more maintainable and less redundant, including Rails. This means that with Rails, code blocks should not be duplicated, especially if they carry out comparable functions.

13. Why Ruby is known as a language of flexibility?

Ruby’s rich syntax and dynamic nature provide it versatility. Ruby allows you to construct variables and methods without defining their data types, in contrast to statically typed languages. Development can proceed more fluidly and with more code structure flexibility because to this dynamic typing.

Ruby’s expressive syntax, which prioritizes readability and uses techniques akin to natural language, helps programmers generate code that is frequently elegant and succinct. Because of its adaptability to multiple programming styles and methodologies, Ruby may be used for a wide range of project requirements. Further adding to Ruby’s image as a flexible language are its metaprogramming features, which include method declarations and object change at runtime. These features offer a great degree of customisation and flexibility.

14. Explain Ruby class.

An object’s blueprint is found in a Ruby class. It outlines the characteristics (instance variables) and actions (methods) that those class’s objects will have. Consider a class as a cookie cutter; it establishes the features and form of the cookies (items) that are made from it.

You establish instance variables inside a class to hold information unique to each object. Methods are used to access and change these variables. Code segments known as methods are used to operate on or with an object’s data. Objects that include both data and behavior can be made by mixing methods and instance variables.

A Person class, for instance, might contain instance variables for address, name, and age. Additionally, it may have birthday, walk, and welcome techniques. A newly created Person object can call the class’s defined methods and will have its own distinct values for these instance variables.

15.Define Ruby methods.

Ruby methods are code snippets that carry out particular tasks. They enable you to encapsulate functionality and reuse it across your code, making them fundamental building blocks of Ruby programs. The def keyword is used to define a method. The method name and a block of code surrounded in curly braces {} or do…end follow.

When a method is called, it may accept arguments, which are values that are supplied to it. The method can conduct computations or change the object’s state using these arguments. Additionally, methods can return values that you can utilize in other sections of your code. This enables you to write reusable and modular code, which improves the organization and maintainability of your programs.

16. What are Ruby blocks.

Anonymous code segments called Ruby blocks can be supplied as parameters to methods. They are an essential idea in Ruby that offer a potent means of reusing and encapsulating code. Data manipulation, filtering, and iteration are common uses for blocks.

The do…end syntax or the curly brackets {} are used to define blocks. When a block is run, it receives arguments that it may choose to accept. A method can launch a block and give any required parameters by using the yield keyword when it gets a block as an input. Because methods can modify their behavior in response to the blocks that are provided, programming can become more flexible and dynamic.

17.What is yield statement in Ruby.

In Ruby, a block of code that has been supplied as an input to a method can be invoked using the yield keyword. The yield keyword in a method denotes that the procedure anticipates receiving a block. The yield statement causes the block of code to be executed when the method is invoked with a block.

Arguments can also be passed to the block using the yield statement. You can put arguments in parenthesis following the yield keyword if you wish to pass them. The block will get these arguments when it is performed. A significant technique for developing reusable and adaptable methods that can change their behavior based on the blocks that are provided is the yield statement.

18.Explain Ruby module ?

A group of constants and methods that can be used in other classes or modules is called a Ruby module. It offers a method for arranging and reusing code, encouraging modularity and reusability. Unlike classes, modules cannot be instantiated; their only purpose is to offer functionality.

The module keyword and the module name are used to define modules. Using the include keyword, one can include a module in a class or another module to have access to its defined methods and constants. This enables you to add more methods and constants to classes and modules to increase their usefulness. Namespaces can also be created with modules, which helps to avoid naming conflicts in your code.

Modules basically serve two purposes:

• They act as namespace. They prevent the name clashes.
• They allow the mixin facility to share functionality between classes.

19. How to write multiline string in Ruby.

In Ruby, creating multiline strings is quite easy. We’ll go over three methods for printing multiline strings.

• You can write a string between double quotations.
• The string is encased in the / character and the % character is used.
• The string is enclosed within the term STRING in the heredoc syntax, and we use \.

20.What are Ruby arrays and how they can be created?

Ordered collections of things make up a ruby array. Objects such as integers, numbers, hashes, strings, symbols, and other arrays can be stored in them.

Its index number begins at 0. The array’s end is where the negative index begins, at -1. For instance, 0 denotes the array’s first element while -1 denotes its last element.

A Ruby array is created in many ways.

• Using literal constructor []
• Using new class method