After toying around with Ruby a little and reading through the book Programming Ruby see below for the first class I made.

# product
class Product
  def initialize( id, description )
    @id = id
    @description = description
  end
end

	
aProduct = Product.new( ‘demo’, ‘Demo part’ )
puts aProduct.inspect


	
class Product
  def to_s
    ”#{@id}: #{@description}” 
  end
end


	
bProduct = Product.new( ‘demo2’, ‘Another demo part’ )
puts bProduct.to_s


	
class SNProduct < Product
  def initialize( id, description, sn )
    super(id,description)
    @sn = sn
  end
  def to_s
    super + ” [#{@sn}]” 
  end
end


snProduct = SNProduct.new( ‘demo-sn’, ‘SN Tracked part’, 123456789 )
puts snProduct.to_s