What are modules in Ruby and how do I use them?

What are modules in Ruby and how do I use them?

Modules in Ruby are a way to group related methods, classes, and constants. They help in organizing code and can be mixed into classes.

Can you give me an example of how to create a module?

Sure! Here's a simple example:

module Greeting
  def hello
    puts 'Hello, world!'
  end
end

How do I include this module in a class?

You can include the module in a class like this:

class MyClass
  include Greeting
end

What happens if I include multiple modules?

If you include multiple modules, Ruby will mix in the methods from all included modules, allowing you to use them in your class.