Searching an array of arrays

Never mind. Figured it out..

PAYMENT_TYPES.rassoc("MC")[0] would give you "MasterCard"


That's pretty inefficient. You could use a hash:

PAYMENT_TYPES = { 'MC'=>'MasterCard', 'VISA'=>'Visa',
'AMEX'=>'American Express']

and then:

You should strongly consider storing the display names in the database
as well. Your current setup distributes the business data across two
different layers (database and domain model), which is generally not a
good idea.