Question

ActiveSupport offers the nice method to_sentence. Thus,

require 'active_support'
[1,2,3].to_sentence  # gives "1, 2, and 3"
[1,2,3].to_sentence(:last_word_connector => ' and ')  # gives "1, 2 and 3"

it’s good that you can change the last word connector, because I prefer not to have the extra comma. but it takes so much extra text: 44 characters instead of 11!

the question: what’s the most ruby-like way to change the default value of :last_word_connector to ' and '?

Answer 1

As an answer to how to override a method in general, a post here gives a nice way of doing it. It doesn’t suffer from the same problems as the alias technique, as there isn’t a leftover “old” method.

Here how you could use that technique with your original problem (tested with ruby 1.9)

class Array
  old_to_sentence = instance_method(:to_sentence)
  define_method(:to_sentence) { |options = {}|

    options[:last_word_connector] ||= " and "
    old_to_sentence.bind(self).call(options)
  }
end

You might also want read up on UnboundMethod if the above code is confusing. Note that old_to_sentence goes out of scope after the end statement, so it isn’t a problem for future uses of Array.