What is a Ruby Eigenclass?

The Eigenclass When you create an instance of a class, Ruby creates a hidden class, basically a copy of the original class, but that is owned exclusively by this instance. This is the Eigenclass. If you modify the Eigenclass of your first instance, it won’t change anything for another instance.

What is a singleton class in Ruby?

Singleton is a creational design pattern, which ensures that only one object of its kind exists and provides a single point of access to it for any other code. Singleton has almost the same pros and cons as global variables. Although they’re super-handy, they break the modularity of your code.

What is class method in Ruby?

Class Methods are the methods that are defined inside the class, public class methods can be accessed with the help of objects. The method is marked as private by default, when a method is defined outside of the class definition. By default, methods are marked as public which is defined in the class definition.

What are Ruby callbacks?

Callbacks are methods that get called at certain moments of an object’s life cycle. With callbacks it is possible to write code that will run whenever an Active Record object is created, saved, updated, deleted, validated, or loaded from the database.

What is Attr_accessor in Ruby?

In Ruby, object methods are public by default, while data is private. attr_accessor is a shortcut method when you need both attr_reader and attr_writer . Since both reading and writing data are common, the idiomatic method attr_accessor is quite useful.

What is self in Ruby?

The keyword self in Ruby enables you to access to the current object — the object that is receiving the current message. Using self inside an instance or class method refers to the same object the method is being called on, i.e., and instance and class respectively. In an instance method such as #say_hi, using self.

What is RubyMonk?

If you’re looking to get into web development and want to learn one of the more popular programming languages on the web, RubyMonk can teach you to code in the Ruby language. It features interactive lessons and exercises that you can learn right from your web browser so you can participate from practically anywhere.

Does Update_attributes call save?

update_attribute calls save on the object, which is unnecessary in this case, since the statement is inside a before_save callback and will get saved anyway.

What is hook in Ruby?

Ruby Hook Methods are called in reaction to something you do. They are usually used to extend the working of methods at run time. These methods are not defined by default, but a programmer can define them according to imply them on any object or class or module and they will come into picture when certain events occur.

What is initialize in Ruby?

The initialize method is part of the object-creation process in Ruby & it allows you to set the initial values for an object. In other programming languages they call this a “constructor”. For example: Let’s say that you have a Point class, this point needs two coordinates, x & y .