Multiplying the contents of two arrays (not the arrays themselves)

I want to make an array with every card in the deck, so it would be ["Ac", "Ad", "Ah", "As", "Kc", ...] though order is not important.

Isn't there a way that inject could be used to solve this problem? This was as close as I could get.

cards = ["A", "K", "Q", "J", "T", "9", "8", "7", "6", "5", "4", "3", "2"] 
suits = ["c", "s", "d", "h"] 
ruby-1.9.2-p180 :025 > car开发者_StackOverflow社区ds.inject(suits) { |suit, card| suit.map{|s| "#{card}#{s}"}}
 => ["23456789TJQKAc", "23456789TJQKAs", "23456789TJQKAd", "23456789TJQKAh"] 

Is this what you aim to do?

cards.map { |card|
  suits.map { |suit| "#{card}#{suit}" }
}.flatten

Or maybe something similar to

cards.product( suits ).map(&:join)

This doesn't use inject but thought worth mentioning: Array#product. See answer to similar question here