Ruby 2.0 introduces keyword arguments

"Keyword arguments" allow naming method arguments (optionally setting a default value). By using the double-splat operator, you can collect additional options. Default values for standard arguments still work (see adjective).

Copydef greet(name, adjective = 'happy', suffix: '!', count: 7, **options)
  greeting = options[:letter] ? 'Dear' : 'Hello'
  puts "#{greeting} #{adjective} #{name + suffix * count}"
end

Invoke the method like this:

Copygreet('Otto', 'sad', suffix: '??', count: 9, include_blank: true)

In Ruby 2.1+, you can also make an argument required by not giving it a default value: def something(required_option:).