#---
# Excerpted from "Seven Languages in Seven Weeks",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material, 
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose. 
# Visit http://www.pragmaticprogrammer.com/titles/btlang for more book information.
#---
class NilClass
  def blank?
    true
  end
end

class String
  def blank?
    self.size == 0
  end
end

["", "person", nil].each do |element| 
  puts element unless element.blank? 
end