Usman Y回答的Swift 2.1版本。 使用print语句来验证，因此调用某个字符串值

print(self.validateCardType(self.creditCardField.text!))

func validateCardType(testCard: String) -> String {

    let regVisa = "^4[0-9]{12}(?:[0-9]{3})?$"
    let regMaster = "^5[1-5][0-9]{14}$"
    let regExpress = "^3[47][0-9]{13}$"
    let regDiners = "^3(?:0[0-5]|[68][0-9])[0-9]{11}$"
    let regDiscover = "^6(?:011|5[0-9]{2})[0-9]{12}$"
    let regJCB = "^(?:2131|1800|35\\d{3})\\d{11}$"


    let regVisaTest = NSPredicate(format: "SELF MATCHES %@", regVisa)
    let regMasterTest = NSPredicate(format: "SELF MATCHES %@", regMaster)
    let regExpressTest = NSPredicate(format: "SELF MATCHES %@", regExpress)
    let regDinersTest = NSPredicate(format: "SELF MATCHES %@", regDiners)
    let regDiscoverTest = NSPredicate(format: "SELF MATCHES %@", regDiscover)
    let regJCBTest = NSPredicate(format: "SELF MATCHES %@", regJCB)


    if regVisaTest.evaluateWithObject(testCard){
        return "Visa"
    }
    else if regMasterTest.evaluateWithObject(testCard){
        return "MasterCard"
    }

    else if regExpressTest.evaluateWithObject(testCard){
        return "American Express"
    }

    else if regDinersTest.evaluateWithObject(testCard){
        return "Diners Club"
    }

    else if regDiscoverTest.evaluateWithObject(testCard){
        return "Discover"
    }

    else if regJCBTest.evaluateWithObject(testCard){
        return "JCB"
    }

    return ""

}

在卡牌范围识别(CRR)中，使用一系列正则表达式或其他硬编码范围的算法的一个缺点是，根据我的经验，bin / iin会随着时间的推移而变化。信用卡的联合品牌是一个持续的复杂问题。不同的购卡商/商家可能会要求你不同地对待同一张卡，这取决于例如地理位置。

Additionally, in the last few years with e.g. UnionPay cards in wider circulation, existing models do not cope with new ranges that sometimes interleave with broader ranges that they supersede. Knowing the geography your system needs to cover may help, as some ranges are restricted to use in particular countries. For example, ranges 62 include some AAA sub-ranges in the US, but if your merchant base is outside the US, you may be able to treat all 62 as UnionPay. You may be also asked to treat a card differently based on merchant location. E.g. to treat certain UK cards as debit domestically, but as credit internationally.

There are very useful set of rules maintained by one major Acquiring Bank. E.g. https://www.barclaycard.co.uk/business/files/BIN-Rules-EIRE.pdf and https://www.barclaycard.co.uk/business/files/BIN-Rules-UK.pdf. (Valid links as of June 2017, thanks to the user who provided a link to updated reference.) But be aware of the caveat that, while these CRR rules may represent the Card Issuing universe as it applies to the merchants acquired by that entity, it does not include e.g. ranges identified as CUP/UPI.

这些注释适用于磁条(MagStripe)或PKE (Pan Key Entry)场景。在ICC/EMV领域，情况又有所不同。

更新:本页上的其他答案(以及链接的维基百科页面)的JCB始终是16长。然而，在我的公司，我们有一个专门的工程师团队，他们在多个银行和地区认证我们的POS设备和软件。这个团队从JCB获得的最新认证卡包，有一个19长PAN的合格案例。

压缩javascript版本

    var getCardType = function (number) {
        var cards = {
            visa: /^4[0-9]{12}(?:[0-9]{3})?$/,
            mastercard: /^5[1-5][0-9]{14}$/,
            amex: /^3[47][0-9]{13}$/,
            diners: /^3(?:0[0-5]|[68][0-9])[0-9]{11}$/,
            discover: /^6(?:011|5[0-9]{2})[0-9]{12}$/,
            jcb: /^(?:2131|1800|35\d{3})\d{11}$/
        };
        for (var card in cards) {
            if (cards[card].test(number)) {
                return card;
            }
        }
    };

不要试图检测信用卡类型作为处理支付的一部分。您正在冒着拒绝有效事务的风险。

如果您需要向您的支付处理器提供信息(例如，PayPal信用卡对象需要命名卡类型)，那么从可用的最少信息中猜测它，例如。

$credit_card['pan'] = preg_replace('/[^0-9]/', '', $credit_card['pan']);
$inn = (int) mb_substr($credit_card['pan'], 0, 2);

// @see http://en.wikipedia.org/wiki/List_of_Bank_Identification_Numbers#Overview
if ($inn >= 40 && $inn <= 49) {
    $type = 'visa';
} else if ($inn >= 51 && $inn <= 55) {
    $type = 'mastercard';
} else if ($inn >= 60 && $inn <= 65) {
    $type = 'discover';
} else if ($inn >= 34 && $inn <= 37) {
    $type = 'amex';
} else {
    throw new \UnexpectedValueException('Unsupported card type.');
}

这个实现(只使用前两位数字)足以识别所有主要的(在PayPal的情况下是所有受支持的)卡片方案。实际上，您可能希望完全跳过异常，并默认使用最流行的卡片类型。让支付网关/处理器告诉您在响应您的请求时是否存在验证错误。

现实情况是，你的支付网关并不关心你提供的价值。

匹配对应卡供应商的正则表达式规则:

(4\d{12}(?:\d{3})?) (5[1-5]\d{14}) (3[47]\d{13})为美国运通。 ((?: 5020 | 5038 | 6304 | 6579 | 6761) \ d {12} (?: \ \ d) ?)大师。 (3(?:0[0-5]|[68][0-9])[0-9]{11}) (6(?:011|5[0-9]{2})[0-9]{12})用于发现。 (35[2-8][89]\d\d\d{10})

public string GetCreditCardType(string CreditCardNumber)
{
    Regex regVisa = new Regex("^4[0-9]{12}(?:[0-9]{3})?$");
    Regex regMaster = new Regex("^5[1-5][0-9]{14}$");
    Regex regExpress = new Regex("^3[47][0-9]{13}$");
    Regex regDiners = new Regex("^3(?:0[0-5]|[68][0-9])[0-9]{11}$");
    Regex regDiscover = new Regex("^6(?:011|5[0-9]{2})[0-9]{12}$");
    Regex regJCB = new Regex("^(?:2131|1800|35\\d{3})\\d{11}$");


    if (regVisa.IsMatch(CreditCardNumber))
        return "VISA";
    else if (regMaster.IsMatch(CreditCardNumber))
        return "MASTER";
    else  if (regExpress.IsMatch(CreditCardNumber))
        return "AEXPRESS";
    else if (regDiners.IsMatch(CreditCardNumber))
        return "DINERS";
    else if (regDiscover.IsMatch(CreditCardNumber))
        return "DISCOVERS";
    else if (regJCB.IsMatch(CreditCardNumber))
        return "JCB";
    else
        return "invalid";
}

下面是使用Regex, c#检查信用卡类型的函数