Module declaration syntax in Ruby - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the basic syntax to declare a module in Ruby?

Use the module keyword followed by the module name and end. For example:<br>

module MyModule
  # code here
end

beginner

Can a Ruby module contain methods and constants?

Yes, a Ruby module can contain methods, constants, and even other modules or classes. It acts like a container for related code.

beginner

How do you define a method inside a Ruby module?

Inside the module block, define methods just like in a class using <code>def method_name</code>. For example:<br><pre>module Greetings
  def hello
    puts 'Hello!'
  end
end</pre>

intermediate

What is the purpose of using modules in Ruby?

Modules group related methods and constants together. They help organize code and can be mixed into classes to share behavior without inheritance.

intermediate

Is it possible to nest modules inside other modules in Ruby?

Yes, Ruby allows nesting modules inside other modules to create a hierarchy or namespace. For example:<br>

module Outer
  module Inner
    # code
  end
end
end

Which keyword starts a module declaration in Ruby?

A package

B module

C def

D class

The module keyword is used to declare a module in Ruby.

What keyword ends a module declaration in Ruby?

A end

B stop

C close

D finish

Ruby uses end to close blocks including modules.

Can a Ruby module contain instance variables?

A Modules can have instance variables but they behave differently

B Yes, like classes

C Modules can have class variables but not instance variables

D No, modules cannot have any variables

Modules can have instance variables, but they belong to the module itself, not to instances like in classes.

How do you call a method defined inside a module without including it in a class?

A new module_name.method_name()

B method_name()

C module_name.method_name

D You cannot call it without including

You can call module methods directly using the module name if they are defined as module methods (e.g., with self.method_name).

What is a common use of modules in Ruby?

A To create objects

B To replace classes

C To store global variables

D To share reusable code across classes

Modules are often used to share reusable methods and constants across multiple classes.

Explain how to declare a module in Ruby and what it can contain.

Think about the structure and what you can put inside the module.

Describe why and how you would use modules in Ruby programming.

Consider how modules help avoid repeating code.