Module methods in Ruby - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a module method in Ruby?

A module method is a method defined inside a module that can be called on the module itself or included in classes. It helps group related methods without creating objects.

beginner

How do you define a module method that can be called directly on the module?

You define it using def self.method_name inside the module. This makes the method callable on the module itself, like ModuleName.method_name.

intermediate

What is the difference between def method_name and def self.method_name inside a module?

def method_name defines an instance method for classes that include the module.<br>def self.method_name defines a module method callable directly on the module.

beginner

How can you call a module method after defining it with def self.method_name?

Call it by using the module name followed by the method name, like ModuleName.method_name.

beginner

Can module methods be used without including the module in a class?

Yes, module methods defined with def self.method_name can be called directly on the module without including it in any class.

How do you define a method inside a module that can be called directly on the module?

A def method_name

B def @method_name

C def module.method_name

D def self.method_name

Using def self.method_name defines a module method callable on the module itself.

What happens if you define def method_name inside a module and include that module in a class?

A The method becomes an instance method of the class

B The method becomes a class method of the class

C The method can only be called on the module

D The method is private and cannot be called

Instance methods defined in modules become instance methods of classes that include the module.

Which of these calls a module method correctly?

A ModuleName.method_name

B ModuleName#method_name

C method_name()

D include ModuleName.method_name

Module methods are called on the module using dot notation: ModuleName.method_name.

Can you call a module method without including the module in a class?

A No, you must include the module first.

B Yes, if it is defined with self.

C Only if the module is a subclass.

D Only if the method is public.

Module methods defined with self. can be called directly on the module without including it.

What keyword is used to define a module method inside a module?

A class

B module

C self

D defmodule

The keyword self is used to define methods on the module itself.

Explain how to define and call a module method in Ruby.

Think about how to make a method belong to the module itself.

Describe the difference between instance methods and module methods inside a Ruby module.

Focus on where and how each method is called.