ruby_errors.rb

class Table
  attr_reader :num_legs

  def initialize(num_legs)
    if num_legs > 0
      @num_legs = num_legs
    elsif num_legs == 0
      raise "Tables have one or more legs."
    else
      raise ArgumentError, "The number of legs has to be greater than zero."
    end
  end
end

legs = -1

begin
  t = Table.new legs
  p t
rescue ArgumentError
  puts "So sorry!"
rescue
  puts "Say what?"
end

puts "All done!"