Product

product.rb

# arr.product( ‹ arrays›* ) → result_array 
# arr.product( ‹ arrays›* ) ‹{|combination| … }› → arr

suits = %w[ C D H S ]   
ranks = [ *2..10, *%w{ J Q K A }]

card_deck = suits.product(ranks).shuffle
card_deck.first(13) # => [["H", "Q"], ["D", 7], ["S", "A"], ["S", "J"], 
                    # .. ["D", 2], ["S", 10], ["D", 4], ["S", 9], ["C", 7], 
                    # .. ["C", 4], ["H", 5], ["D", 5], ["S", 4]]