How can I extend a module in Ruby?

How can I extend a module in Ruby?

In Ruby, you can extend a module by using the extend keyword. This allows you to add module methods as class methods.

Can you give me an example of extending a module?

Sure! Here's a simple example:

module Greetings
  def hello
    "Hello!"
  end
end

class Person
  extend Greetings
end

puts Person.hello  # Outputs: Hello!

What if I want to include the module instead of extending it?

If you include a module, its methods become instance methods. You can do this using the include keyword. Here's an example:

class Person
  include Greetings
end

person = Person.new
puts person.hello  # Outputs: Hello!

Are there any differences in behavior between extend and include?

Yes, the main difference is that extend adds methods as class methods, while include adds them as instance methods.