Ordinal Numbers Done Right

August 15, 2006

I found some Ruby code for Ordinals today that was wrong. Here’s the issue:


irb(main):011:0> 112.ordinal
=> "112nd"

Wow thats WRONG. So, I fixed it:


class Numeric
  def ordinal
    cardinal = self.to_i.abs
    if (10...20).include?(cardinal%100) then
      cardinal.to_s << 'th'
    else
      cardinal.to_s << %w{th st nd rd th th th th th th}[cardinal % 10]
    end
  end
end


irb(main):011:0> 112.ordinal
=> "112th"
irb(main):012:0> 1234.ordinal
=> "1234th"
irb(main):013:0> 1211.ordinal
=> "1211th"

Yes, I know, I saved the day. Again.



Posted, by in Uncategorized Tags:

Comments

  1. Benjamin

    August 15, 2006 at 5:41 PM

    I love ordinals. Nicely done there, way to save the day as you said! hee – ben @ http://rubyonrailsblog.com/