class Fixnum
  # Returns the length of the number's string representation.
  #     0.string_length
  #     #=> 1
  #     123.string_length
  #     #=> 3
  #     -1.string_length
  #     #=> 2
  def string_length
    return 1 if self.zero?
    len = Math.log10(self.abs).floor.next
    self > 0 ? len : len.next
  end
end