[algorithm] How do you detect Credit card type based on number?

The first numbers of the credit card can be used to approximate the vendor:

  • Visa: 49,44 or 47
  • Visa electron: 42, 45, 48, 49
  • MasterCard: 51
  • Amex:34
  • Diners: 30, 36, 38
  • JCB: 35