试试kotlin。添加Regex并添加到when语句中。

private fun getCardType(number: String): String {

        val visa = Regex("^4[0-9]{12}(?:[0-9]{3})?$")
        val mastercard = Regex("^5[1-5][0-9]{14}$")
        val amx = Regex("^3[47][0-9]{13}$")

        return when {
            visa.matches(number) -> "Visa"
            mastercard.matches(number) -> "Mastercard"
            amx.matches(number) -> "American Express"
            else -> "Unknown"
        }
    }

在swift中，您可以创建一个枚举来检测信用卡类型。

enum CreditCardType: Int { // Enum which encapsulates different card types and method to find the type of card.

case Visa
case Master
case Amex
case Discover

func validationRegex() -> String {
    var regex = ""
    switch self {
    case .Visa:
        regex = "^4[0-9]{6,}$"

    case .Master:
        regex = "^5[1-5][0-9]{5,}$"

    case .Amex:
        regex = "^3[47][0-9]{13}$"

    case .Discover:
        regex = "^6(?:011|5[0-9]{2})[0-9]{12}$"
    }

    return regex
}

func validate(cardNumber: String) -> Bool {
    let predicate = NSPredicate(format: "SELF MATCHES %@", validationRegex())
    return predicate.evaluateWithObject(cardNumber)
}

// Method returns the credit card type for given card number
static func cardTypeForCreditCardNumber(cardNumber: String) -> CreditCardType?  {
    var creditCardType: CreditCardType?

    var index = 0
    while let cardType = CreditCardType(rawValue: index) {
        if cardType.validate(cardNumber) {
            creditCardType = cardType
            break
        } else {
            index++
        }
    }
    return creditCardType
  }
}

调用方法CreditCardType。cardTypeForCreditCardNumber(“#卡号”)返回CreditCardType enum值。

信用卡的第一个数字可以用来大致了解供应商:

签证:49、44或47 Visa电子:42、45、48、49 万事达卡:51 美国运通:34 就餐者:30、36、38 JCB: 35

另一个api解决方案在rapidapi银行卡位数检查有250K+发行卡类型。

只有一个GET rest api请求，并获得发卡机构信息，如:

{ "bin_number": 535177, "bank": "Finansbank A.S.", "scheme": "MASTERCARD", "type": "Debit", "country": "Turkey" }

更新日期:2016年6月15日(目前为最终解决方案)

请注意，我甚至放弃投票给一个被投票最多的，但为了明确这些是regexp实际上是有效的，我用数千个真实的BIN代码测试了它。最重要的是使用开始字符串(^)，否则在现实世界中会给出错误的结果!

JCB ^(?:2131|1800|35)[0-9]{0，}$开始:2131,1800,35 (3528-3589)

美国运通^3[47][0-9]{0，}$以:34,37开头

大莱卡^ 3(?:0(0-59){1}|[689])[0 - 9]{0}$开头:300 - 305年,309年,36岁,38-39

Visa ^4[0-9]{0，}$以:4开头

万事达卡^(5[1 - 5]| 222(1 - 9)| 22(3 - 9)| 2(3 - 6)| 27[01]| 2720)[0 - 9]{0}$开头:2221 - 2720,51-55

Maestro ^(5[06789]|6)[0-9]{0，}$ Maestro总是在范围内增长:60-69，以/开始，但开始5必须编码为万事达卡。大师卡必须在代码的末尾被检测到，因为其他一些卡的范围在60-69之间。请看代码。

发现^(6011|65|64[4-9]|62212[6-9]|6221[3-9]|622[2-8]|6229[01]|62292[0-5])[0-9]{0，}$发现很难编码，从:6011,622126 - 622925,644 -649,65开始

在javascript中，我使用这个函数。当你把它分配给一个onkeyup事件并尽快给出结果时，这是很好的。

function cc_brand_id(cur_val) {
    // the regular expressions check for possible matches as you type, hence the OR operators based on the number of chars
    // regexp string length {0} provided for soonest detection of beginning of the card numbers this way it could be used for BIN CODE detection also

    //JCB
    jcb_regex = new RegExp('^(?:2131|1800|35)[0-9]{0,}$'); //2131, 1800, 35 (3528-3589)
    // American Express
    amex_regex = new RegExp('^3[47][0-9]{0,}$'); //34, 37
    // Diners Club
    diners_regex = new RegExp('^3(?:0[0-59]{1}|[689])[0-9]{0,}$'); //300-305, 309, 36, 38-39
    // Visa
    visa_regex = new RegExp('^4[0-9]{0,}$'); //4
    // MasterCard
    mastercard_regex = new RegExp('^(5[1-5]|222[1-9]|22[3-9]|2[3-6]|27[01]|2720)[0-9]{0,}$'); //2221-2720, 51-55
    maestro_regex = new RegExp('^(5[06789]|6)[0-9]{0,}$'); //always growing in the range: 60-69, started with / not something else, but starting 5 must be encoded as mastercard anyway
    //Discover
    discover_regex = new RegExp('^(6011|65|64[4-9]|62212[6-9]|6221[3-9]|622[2-8]|6229[01]|62292[0-5])[0-9]{0,}$');
    ////6011, 622126-622925, 644-649, 65


    // get rid of anything but numbers
    cur_val = cur_val.replace(/\D/g, '');

    // checks per each, as their could be multiple hits
    //fix: ordering matter in detection, otherwise can give false results in rare cases
    var sel_brand = "unknown";
    if (cur_val.match(jcb_regex)) {
        sel_brand = "jcb";
    } else if (cur_val.match(amex_regex)) {
        sel_brand = "amex";
    } else if (cur_val.match(diners_regex)) {
        sel_brand = "diners_club";
    } else if (cur_val.match(visa_regex)) {
        sel_brand = "visa";
    } else if (cur_val.match(mastercard_regex)) {
        sel_brand = "mastercard";
    } else if (cur_val.match(discover_regex)) {
        sel_brand = "discover";
    } else if (cur_val.match(maestro_regex)) {
        if (cur_val[0] == '5') { //started 5 must be mastercard
            sel_brand = "mastercard";
        } else {
            sel_brand = "maestro"; //maestro is all 60-69 which is not something else, thats why this condition in the end
        }
    }

    return sel_brand;
}

在这里你可以玩它:

http://jsfiddle.net/upN3L/69/

对于PHP使用这个函数，它也会检测一些子VISA/MC卡:

/**
  * Obtain a brand constant from a PAN
  *
  * @param string $pan               Credit card number
  * @param bool   $include_sub_types Include detection of sub visa brands
  * @return string
  */
public static function getCardBrand($pan, $include_sub_types = false)
{
    //maximum length is not fixed now, there are growing number of CCs has more numbers in length, limiting can give false negatives atm

    //these regexps accept not whole cc numbers too
    //visa
    $visa_regex = "/^4[0-9]{0,}$/";
    $vpreca_regex = "/^428485[0-9]{0,}$/";
    $postepay_regex = "/^(402360|402361|403035|417631|529948){0,}$/";
    $cartasi_regex = "/^(432917|432930|453998)[0-9]{0,}$/";
    $entropay_regex = "/^(406742|410162|431380|459061|533844|522093)[0-9]{0,}$/";
    $o2money_regex = "/^(422793|475743)[0-9]{0,}$/";

    // MasterCard
    $mastercard_regex = "/^(5[1-5]|222[1-9]|22[3-9]|2[3-6]|27[01]|2720)[0-9]{0,}$/";
    $maestro_regex = "/^(5[06789]|6)[0-9]{0,}$/";
    $kukuruza_regex = "/^525477[0-9]{0,}$/";
    $yunacard_regex = "/^541275[0-9]{0,}$/";

    // American Express
    $amex_regex = "/^3[47][0-9]{0,}$/";

    // Diners Club
    $diners_regex = "/^3(?:0[0-59]{1}|[689])[0-9]{0,}$/";

    //Discover
    $discover_regex = "/^(6011|65|64[4-9]|62212[6-9]|6221[3-9]|622[2-8]|6229[01]|62292[0-5])[0-9]{0,}$/";

    //JCB
    $jcb_regex = "/^(?:2131|1800|35)[0-9]{0,}$/";

    //ordering matter in detection, otherwise can give false results in rare cases
    if (preg_match($jcb_regex, $pan)) {
        return "jcb";
    }

    if (preg_match($amex_regex, $pan)) {
        return "amex";
    }

    if (preg_match($diners_regex, $pan)) {
        return "diners_club";
    }

    //sub visa/mastercard cards
    if ($include_sub_types) {
        if (preg_match($vpreca_regex, $pan)) {
            return "v-preca";
        }
        if (preg_match($postepay_regex, $pan)) {
            return "postepay";
        }
        if (preg_match($cartasi_regex, $pan)) {
            return "cartasi";
        }
        if (preg_match($entropay_regex, $pan)) {
            return "entropay";
        }
        if (preg_match($o2money_regex, $pan)) {
            return "o2money";
        }
        if (preg_match($kukuruza_regex, $pan)) {
            return "kukuruza";
        }
        if (preg_match($yunacard_regex, $pan)) {
            return "yunacard";
        }
    }

    if (preg_match($visa_regex, $pan)) {
        return "visa";
    }

    if (preg_match($mastercard_regex, $pan)) {
        return "mastercard";
    }

    if (preg_match($discover_regex, $pan)) {
        return "discover";
    }

    if (preg_match($maestro_regex, $pan)) {
        if ($pan[0] == '5') { //started 5 must be mastercard
            return "mastercard";
        }
        return "maestro"; //maestro is all 60-69 which is not something else, thats why this condition in the end

    }

    return "unknown"; //unknown for this system
}

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})