我想知道如何仅根据信用卡的号码来判断信用卡的类型。有谁知道确定可靠的方法吗?
当前回答
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 ""
}
其他回答
follow Luhn’s algorithm
private boolean validateCreditCardNumber(String str) {
int[] ints = new int[str.length()];
for (int i = 0; i < str.length(); i++) {
ints[i] = Integer.parseInt(str.substring(i, i + 1));
}
for (int i = ints.length - 2; i >= 0; i = i - 2) {
int j = ints[i];
j = j * 2;
if (j > 9) {
j = j % 10 + 1;
}
ints[i] = j;
}
int sum = 0;
for (int i = 0; i < ints.length; i++) {
sum += ints[i];
}
if (sum % 10 == 0) {
return true;
} else {
return false;
}
}
then call this method
Edittext mCreditCardNumberEt;
mCreditCardNumberEt.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
int cardcount= s.toString().length();
if(cardcount>=16) {
boolean cardnumbervalid= validateCreditCardNumber(s.toString());
if(cardnumbervalid) {
cardvalidtesting.setText("Valid Card");
cardvalidtesting.setTextColor(ContextCompat.getColor(context,R.color.green));
}
else {
cardvalidtesting.setText("Invalid Card");
cardvalidtesting.setTextColor(ContextCompat.getColor(context,R.color.red));
}
}
else if(cardcount>0 &&cardcount<16) {
cardvalidtesting.setText("Invalid Card");
cardvalidtesting.setTextColor(ContextCompat.getColor(context,R.color.red));
}
else {
cardvalidtesting.setText("");
}
}
@Override
public void afterTextChanged(Editable s) {
}
});
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
看看这个:
http://www.breakingpar.com/bkp/home.nsf/0/87256B280015193F87256CC70060A01B
function isValidCreditCard(type, ccnum) {
/* Visa: length 16, prefix 4, dashes optional.
Mastercard: length 16, prefix 51-55, dashes optional.
Discover: length 16, prefix 6011, dashes optional.
American Express: length 15, prefix 34 or 37.
Diners: length 14, prefix 30, 36, or 38. */
var re = new Regex({
"visa": "/^4\d{3}-?\d{4}-?\d{4}-?\d",
"mc": "/^5[1-5]\d{2}-?\d{4}-?\d{4}-?\d{4}$/",
"disc": "/^6011-?\d{4}-?\d{4}-?\d{4}$/",
"amex": "/^3[47]\d{13}$/",
"diners": "/^3[068]\d{12}$/"
}[type.toLowerCase()])
if (!re.test(ccnum)) return false;
// 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;
}
只需一点点的勺子喂养:
$("#CreditCardNumber").focusout(function () {
var regVisa = /^4[0-9]{12}(?:[0-9]{3})?$/;
var regMasterCard = /^5[1-5][0-9]{14}$/;
var regAmex = /^3[47][0-9]{13}$/;
var regDiscover = /^6(?:011|5[0-9]{2})[0-9]{12}$/;
if (regVisa.test($(this).val())) {
$("#CCImage").html("<img height='40px' src='@Url.Content("~/images/visa.png")'>");
}
else if (regMasterCard.test($(this).val())) {
$("#CCImage").html("<img height='40px' src='@Url.Content("~/images/mastercard.png")'>");
}
else if (regAmex.test($(this).val())) {
$("#CCImage").html("<img height='40px' src='@Url.Content("~/images/amex.png")'>");
}
else if (regDiscover.test($(this).val())) {
$("#CCImage").html("<img height='40px' src='@Url.Content("~/images/discover.png")'>");
}
else {
$("#CCImage").html("NA");
}
});
public string GetCreditCardType(string CreditCardNumber)
{
Regex regVisa = new Regex("^4[0-9]{12}(?:[0-9]{3})?$");
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
