una funcion que genere numeros de tarjetas de credito de mastercard y visa

var visa = "4"
var mastercard = 5
var amex = 3
var diners = 3

var ccv = "123"

// function that: creates a random credit card number and ccv

var credit_cards = ["visa", "mastercard", "amex", "diners"]

function random_credit_card(credit_cards){
  var credit_card_prefix = credit_cards[Math.floor(Math.random()*credit_cards.length)]
  var credit_card_number = credit_card_prefix + "1234567890"
  var credit_card_ccv = "123"
  return [credit_card_number, credit_card_ccv]
}