class Integer

  # Factorial of number
  # 5.factorial == 5 x 4 x 3 x 2 x 1 == 120
  #------------------------------------------------------------------------------
  def factorial
    return 1 if self.zero?
    (1..self).inject(:*)
  end

  #------------------------------------------------------------------------------
  def as_boolean
    (self > 0) ? true : false
  end

end