anatoly用PHP回答:

 public static function detectCardType($num)
 {
    $re = array(
        "visa"       => "/^4[0-9]{12}(?:[0-9]{3})?$/",
        "mastercard" => "/^5[1-5][0-9]{14}$/",
        "amex"       => "/^3[47][0-9]{13}$/",
        "discover"   => "/^6(?:011|5[0-9]{2})[0-9]{12}$/",
    );

    if (preg_match($re['visa'],$num))
    {
        return 'visa';
    }
    else if (preg_match($re['mastercard'],$num))
    {
        return 'mastercard';
    }
    else if (preg_match($re['amex'],$num))
    {
        return 'amex';
    }
    else if (preg_match($re['discover'],$num))
    {
        return 'discover';
    }
    else
    {
        return false;
    }
 }

这里有完整的c#或VB代码，用于各种CC相关的东西。

IsValidNumber GetCardTypeFromNumber GetCardTestNumber PassesLuhnTest

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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

// abobjects.com, parvez ahmad ab bulk mailer
use below script

function isValidCreditCard2(type, ccnum) {
       if (type == "Visa") {
          // Visa: length 16, prefix 4, dashes optional.
          var re = /^4\d{3}?\d{4}?\d{4}?\d{4}$/;
       } else if (type == "MasterCard") {
          // Mastercard: length 16, prefix 51-55, dashes optional.
          var re = /^5[1-5]\d{2}?\d{4}?\d{4}?\d{4}$/;
       } else if (type == "Discover") {
          // Discover: length 16, prefix 6011, dashes optional.
          var re = /^6011?\d{4}?\d{4}?\d{4}$/;
       } else if (type == "AmEx") {
          // American Express: length 15, prefix 34 or 37.
          var re = /^3[4,7]\d{13}$/;
       } else if (type == "Diners") {
          // Diners: length 14, prefix 30, 36, or 38.
          var re = /^3[0,6,8]\d{12}$/;
       }
       if (!re.test(ccnum)) return false;
       return true;
       /*
       // Remove all dashes for the checksum checks to eliminate negative numbers
       ccnum = ccnum.split("-").join("");
       // Checksum ("Mod 10")
       // Add even digits in even length strings or odd digits in odd length strings.
       var checksum = 0;
       for (var i=(2-(ccnum.length % 2)); i<=ccnum.length; i+=2) {
          checksum += parseInt(ccnum.charAt(i-1));
       }
       // Analyze odd digits in even length strings or even digits in odd length strings.
       for (var i=(ccnum.length % 2) + 1; i<ccnum.length; i+=2) {
          var digit = parseInt(ccnum.charAt(i-1)) * 2;
          if (digit < 10) { checksum += digit; } else { checksum += (digit-9); }
       }
       if ((checksum % 10) == 0) return true; else return false;
       */

    }
jQuery.validator.addMethod("isValidCreditCard", function(postalcode, element) { 
    return isValidCreditCard2($("#cardType").val(), $("#cardNum").val()); 

}, "<br>credit card is invalid");


     Type</td>
                                          <td class="text">&nbsp; <form:select path="cardType" cssclass="fields" style="border: 1px solid #D5D5D5;padding: 0px 0px 0px 0px;width: 130px;height: 22px;">
                                              <option value="SELECT">SELECT</option>
                                              <option value="MasterCard">Mastercard</option>
                                              <option value="Visa">Visa</option>
                                               <option value="AmEx">American Express</option>
                                              <option value="Discover">Discover</option>
                                            </form:select> <font color="#FF0000">*</font> 

$("#signupForm").validate({

    rules:{
       companyName:{required: true},
       address1:{required: true},
       city:{required: true},
       state:{required: true},
       zip:{required: true},
       country:{required: true},
       chkAgree:{required: true},
       confPassword:{required: true},
       lastName:{required: true},
       firstName:{required: true},
       ccAddress1:{required: true},
       ccZip:{         
           postalcode : true
       },
       phone:{required: true},
       email:{
           required: true,
           email: true
           },
       userName:{
           required: true,
           minlength: 6
           },
       password:{
           required: true,
           minlength: 6
           },          
       cardNum:{           
            isValidCreditCard : true
       },

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。

卡号的前六位数字(包括初始信息信息) 数字)被称为发行者识别号码(IIN)。这些 识别向该卡发行该卡的发卡机构 持有人。其余的数字由发卡机构分配。的 卡号的长度是它的位数。许多发卡机构打印 他们卡上的整个IIN和账号。

基于以上事实，我想保留一段JAVA代码来识别卡片品牌。

样卡类型

public static final String AMERICAN_EXPRESS = "American Express";
public static final String DISCOVER = "Discover";
public static final String JCB = "JCB";
public static final String DINERS_CLUB = "Diners Club";
public static final String VISA = "Visa";
public static final String MASTERCARD = "MasterCard";
public static final String UNKNOWN = "Unknown";

卡前缀

// Based on http://en.wikipedia.org/wiki/Bank_card_number#Issuer_identification_number_.28IIN.29
public static final String[] PREFIXES_AMERICAN_EXPRESS = {"34", "37"};
public static final String[] PREFIXES_DISCOVER = {"60", "62", "64", "65"};
public static final String[] PREFIXES_JCB = {"35"};
public static final String[] PREFIXES_DINERS_CLUB = {"300", "301", "302", "303", "304", "305", "309", "36", "38", "39"};
public static final String[] PREFIXES_VISA = {"4"};
public static final String[] PREFIXES_MASTERCARD = {
        "2221", "2222", "2223", "2224", "2225", "2226", "2227", "2228", "2229",
        "223", "224", "225", "226", "227", "228", "229",
        "23", "24", "25", "26",
        "270", "271", "2720",
        "50", "51", "52", "53", "54", "55"
    };

检查输入的数字是否有任何给定的前缀。

public String getBrand(String number) {

String evaluatedType;
if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_AMERICAN_EXPRESS)) {
    evaluatedType = AMERICAN_EXPRESS;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_DISCOVER)) {
    evaluatedType = DISCOVER;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_JCB)) {
    evaluatedType = JCB;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_DINERS_CLUB)) {
    evaluatedType = DINERS_CLUB;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_VISA)) {
    evaluatedType = VISA;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_MASTERCARD)) {
    evaluatedType = MASTERCARD;
} else {
    evaluatedType = UNKNOWN;
}
    return evaluatedType;
}

最后，效用方法

/**
  * Check to see if the input number has any of the given prefixes.
  *
  * @param number the number to test
  * @param prefixes the prefixes to test against
  * @return {@code true} if number begins with any of the input prefixes
*/

public static boolean hasAnyPrefix(String number, String... prefixes) {
  if (number == null) {
       return false;
  }
   for (String prefix : prefixes) {
       if (number.startsWith(prefix)) {
       return true;
    }
  }
     return false;
}

参考

条纹卡生成器