Can credit card type be determined solely from the credit card number?
Is this recommended or should we always ask client for the type of credit card they're using?
I Googled about it and found this algorithm: http://cuinl.tripod.com/Tips/o-1.htm , is this reliable?
Yes, the site you mentioned is correct. Many sites, incl. Google Checkout I believe, rely on automatic detection of the card type. It's convenient, makes the UI less cluttered (one less input box) and saves time. Go ahead!
I have heard one good reason to make them pick (even though you can figure it out). So that they know the list of credit cards you accept.
As a consumer, I hate choosing a card first. I want to just start typing the number.
This issue is discussed in Wroblewski's Web Form Design on pages 153-154. It's in the section "Removing Questions" of the chapter "Unnecessary Inputs." The example given is Paypal, which highlights the type of card when you've typed in your number.
I am pretty certain that at least for MasterCard, Visa, Discover, and American Express that that is accurate. I have never worked with any of the others.
See the very bottom of this page:
http://www.merchantplus.com/resources/pages/credit-card-logos-and-test-numbers/
Also this might be useful to you"
http://www.beachnet.com/~hstiles/cardtype.html
This is pretty interesting to:
http://en.wikipedia.org/wiki/Bank_card_number
here is the script that i use that works with current card ranges. also does a validity check on the number.
/**
* checks a given string for a valid credit card
* #returns:
* -1 invalid
* 1 mastercard
* 2 visa
* 3 amex
* 4 diners club
* 5 discover
* 6 enRoute
* 7 jcb
*/
function checkCC(val) {
String.prototype.startsWith = function (str) {
return (this.match("^" + str) == str)
}
Array.prototype.has=function(v,i){
for (var j=0;j<this.length;j++){
if (this[j]==v) return (!i ? true : j);
}
return false;
}
// get rid of all non-numbers (space etc)
val = val.replace(/[^0-9]/g, "");
// now get digits
var d = new Array();
var a = 0;
var len = 0;
var cval = val;
while (cval != 0) {
d[a] = cval%10;
cval -= d[a];
cval /= 10;
a++;
len++;
}
if (len < 13)
return -1;
var cType = -1;
// mastercard
if (val.startsWith("5")) {
if (len != 16)
return -1;
cType = 1;
} else
// visa
if (val.startsWith("4")) {
if (len != 16 && len != 13)
return -1;
cType = 2;
} else
// amex
if (val.startsWith("34") || val.startsWith("37")) {
if (len != 15)
return -1;
cType = 3;
} else
// diners
if (val.startsWith("36") || val.startsWith("38") || val.startsWith("300") || val.startsWith("301") || val.startsWith("302") || val.startsWith("303") || val.startsWith("304") || val.startsWith("305")) {
if (len != 14)
return -1;
cType = 4;
} else
// discover
if (val.startsWith("6011")) {
if (len != 15 && len != 16)
return -1;
cType = 5;
} else
// enRoute
if (val.startsWith("2014") || val.startsWith("2149")) {
if (len != 15 && len != 16)
return -1;
// any digit check
return 6;
} else
// jcb
if (val.startsWith("3")) {
if (len != 16)
return -1;
cType = 7;
} else
// jcb
if (val.startsWith("2131") || val.startsWith("1800")) {
if (len != 15)
return -1;
cType = 7;
} else
return - 1;
// invalid cc company
// lets do some calculation
var sum = 0;
var i;
for (i = 1; i < len; i += 2) {
var s = d[i] * 2;
sum += s % 10;
sum += (s - s%10) /10;
}
for (i = 0; i < len; i += 2)
sum += d[i];
// musst be %10
if (sum%10 != 0)
return - 1;
return cType;
}
Here's Complete C# or VB code for all kinds of CC related things on codeproject.
IsValidNumber
GetCardTypeFromNumber
GetCardTestNumber
PassesLuhnTest
This article has been up for a couple years with no negative comments.
Wikipedia contains a list of most card prefixes. Some cards are missing from the link you posted. It also appears that the link you provided is valid.
One reason to ask for the card type is for extra validation, compare what the user provided against the number.
This is the php version of same algorithm mentioned in 1st post
<?php
function CreditCardType($CardNo)
{
/*
'*CARD TYPES *PREFIX *WIDTH
'American Express 34, 37 15
'Diners Club 300 to 305, 36 14
'Carte Blanche 38 14
'Discover 6011 16
'EnRoute 2014, 2149 15
'JCB 3 16
'JCB 2131, 1800 15
'Master Card 51 to 55 16
'Visa 4 13, 16
*/
//Just in case nothing is found
$CreditCardType = "Unknown";
//Remove all spaces and dashes from the passed string
$CardNo = str_replace("-", "",str_replace(" ", "",$CardNo));
//Check that the minimum length of the string isn't less
//than fourteen characters and -is- numeric
If(strlen($CardNo) < 14 || !is_numeric($CardNo))
return false;
//Check the first two digits first
switch(substr($CardNo,0, 2))
{
Case 34: Case 37:
$CreditCardType = "American Express";
break;
Case 36:
$CreditCardType = "Diners Club";
break;
Case 38:
$CreditCardType = "Carte Blanche";
break;
Case 51: Case 52: Case 53: Case 54: Case 55:
$CreditCardType = "Master Card";
break;
}
//None of the above - so check the
if($CreditCardType == "Unknown")
{
//first four digits collectively
switch(substr($CardNo,0, 4))
{
Case 2014:Case 2149:
$CreditCardType = "EnRoute";
break;
Case 2131:Case 1800:
$CreditCardType = "JCB";
break;
Case 6011:
$CreditCardType = "Discover";
break;
}
}
//None of the above - so check the
if($CreditCardType == "Unknown")
{
//first three digits collectively
if(substr($CardNo,0, 3) >= 300 && substr($CardNo,0, 3) <= 305)
{
$CreditCardType = "American Diners Club";
}
}
//None of the above -
if($CreditCardType == "Unknown")
{
//So simply check the first digit
switch(substr($CardNo,0, 1))
{
Case 3:
$CreditCardType = "JCB";
break;
Case 4:
$CreditCardType = "Visa";
break;
}
}
return $CreditCardType;
}
?>
The code you linked has an incomplete BIN/range list for Discover, omits Diner's club (which now belongs to Discover anyway), lists card types that no longer exist and should be folded into other types (enRoute, Carte Blanche), and ignores the increasingly-important Maestro International cart type.
As #Alex confirmed, it's possible to determine the card type from the BIN number, and numerous companies do it but doing so consistently and correctly is not trivial: card brands constantly change, and keeping track of things becomes more complicated as you try to handle regional debit cards (Laser in Ireland, Maestro in Europe, etc) - I have not found a free and maintained (correct) piece of code or algorithm for this anywhere.
As #MitMaro poined out, Wikipedia contains a high-level list of card identifiers, and also a more-specific list of BIN numbers and ranges, which is a good start, and as gbjbaanb commented, Barclays has a publically-published list (but it does not seem to include Discover for some reason - presumably they don't process on the Discover network?)
Trivial as it may seem, a correct card-identification algorithm/method/function takes work to maintain, so unless your detection routine is non-critical/informational (eg #Simon_Weaver's suggestion), OR you're going to put in the work to keep it current, I would recommend that you skip the automatic detection.
Stripe has provided this fantastic javascript library for card scheme detection. Let me add few code snippets and show you how to use it.
Firstly Include it to your web page as
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery.payment/1.2.3/jquery.payment.js " ></script>
Secondly use the function cardType for detecting the card scheme.
$(document).ready(function() {
var type = $.payment.cardType("4242 4242 4242 4242"); //test card number
console.log(type);
});
Here are the reference links for more examples and demos.
Stripe blog for jquery.payment.js
Github repository
Here's a quick a dirty way to determine the card type automatically and show it to the user while they're typing.
That means
a) the user doesnt have to pick it and
b) they wont waste time looking for a dropdown that doesnt exist.
Very simple jQuery version for Amex, Visa and Mastercard.
if you need other card types you can take the
$('[id$=CreditCardNumber]').assertOne().keyup(function(){
// rules taken from http://en.wikipedia.org/wiki/Credit_card_number#cite_note-GenCardFeatures-0
var value = $(this).val();
$('#ccCardType').removeClass("unknown");
if ((/^4/).test(value)) {
$('#ccCardType').html("Visa");
return;
}
if ((/^5[1-5]/).test(value)) {
$('#ccCardType').html("Mastercard");
return;
}
if ((/^3[47]/).test(value)) {
$('#ccCardType').html("Mastercard");
return;
}
$('#ccCardType').html("Enter card number above");
$('#ccCardType').addClass("unknown");
});
This is the jQuery to accompany this (ASP.NET MVC):
Card number: <%= Html.TextBox("PaymentDetails.CreditCardDetails.CreditCardNumber")%>
Card Type: <span id="ccCardType" class="unknown">Enter card number above</span>
I have a css rule for .unknown to display grayed out text.
This implementation in Python should work for AmEx, Discover, Master Card, Visa:
def cardType(number):
number = str(number)
cardtype = "Invalid"
if len(number) == 15:
if number[:2] == "34" or number[:2] == "37":
cardtype = "American Express"
if len(number) == 13:
if number[:1] == "4":
cardtype = "Visa"
if len(number) == 16:
if number[:4] == "6011":
cardtype = "Discover"
if int(number[:2]) >= 51 and int(number[:2]) <= 55:
cardtype = "Master Card"
if number[:1] == "4":
cardtype = "Visa"
return cardtype
If all the credit cards that you accept have the same properties then just let the user enter the card number and other properties (expiry date, CVV, etc). However, some card types require different fields to be entered (e.g. start date or issue number for UK Maestro cards). In those cases, you either have to have all fields, thereby confusing the user, or some Javascript to hide/show the relevant fields, again making the user experience a bit weird (fields disappearing/appearing, as they enter the credit card number). In those cases, I recommend asking for the card type first.
Personally I have no problem with picking the card type first. But there are two aspects of credit card number entry that are problematic in my view.
The worst is the inability to enter spaces between groups of numbers. Including the spaces printed on the physical cards would make the digits vastly easier for the user to scan to verify they've entered the information correctly. Every time I encounter this ubiquitous deficiency I feel like I'm being propelled backwards into a stone age when user input couldn't be filtered to remove unnecessary characters.
The second is the need when placing a phone order to listen to the vendor repeat the card number back to you. All the credit card recipient actually needs is a UI that gives them access to the check digit scheme which verifies that a cc number is valid. According to that algorithm the first 15 (or however many) digits calculate the last digit - and is virtually impossible to "fool." For a fat fingered number to "pass" requires at least two mutually canceling errors among the 15 digits. Unless the algorithm suffers from the defect of being dis-proportionally fooled by transposing adjacent numbers (a common entry error) which I doubt, I except it is more reliable than any human double check.
https://binlist.net/ offers a free API. You only need to enter the first 6 or 8 digits of the card number - i.e. the Issuer Identification Numbers (IIN), previously known as Bank Identification Number (BIN).
curl -H "Accept-Version: 3" "https://lookup.binlist.net/45717360"
NPM: https://www.npmjs.com/package/binlookup
Source: https://github.com/paylike/binlookup
(cross-posted from a more specific question: How tell the difference between a Debit Card and a Credit Card )
Related
I am trying to write a code that will loop you in case you provide wrong data. The problem is that I need to have some type of "Bad data" message for both 2 cases:
- you enter not an integer value
- you enter the value below 0
In this code if you type a letter, it loops you with a message: "Bad data", but if you type for example negative value like -10 Bad data is not appearing (even though validation works and you need to correct number to positive)
How can I do it more universal, so in both scenarios sysout with print on-screen Bad data
Random rand = new Random();
int los = rand.nextInt(11);
int NumberOfPlayers ;
Scanner scan7 = new Scanner(System.in);
System.out.println(" Type number of players :");
do {
while (!scan7.hasNextInt()){
System.out.println(" Bad data");
scan7.next();
}
NumberOfPlayers = scan7.nextInt();
}while (NumberOfPlayers < 0);
you are only validating if scanner has next int, you do not validate it's value, and integers can be negative.
try this solution:
do {
while (!scan7.hasNextInt()) {
System.out.println(" Bad data");
scan7.next();
}
NumberOfPlayers = scan7.nextInt();
if (NumberOfPlayers <= 0) {
System.out.println(" Number must be larger than zero");
}
} while (NumberOfPlayers <= 0);
After checking for next int, I added part checking value of provided int.
ALSO please remember about naming variables and classes - start with small letter, so in your case NumberOfPlayers should be numberOfPlayers.
Why you named scanner scan7? is there valid reason for that name? if no, you should avoid adding numbers to names.
I'm currently learning C programming, and wrote a script similar to one I've written in Python before. My goal is to learn how to pass input to an application and have it process the data I pass it.
The problem I'm having now is the feedback my application is giving me. I wrote a simple application to read keyboard input and give 1 of 3 responses based on what input I give it. The code is as follows:
/*Input test.*/
#include<stdio.h>
#include<stdlib.h>
char input;
const int option_a = 1;
const int option_b = 2;
int main()
{
printf("Lets get started! a for on or b for off?\n");
while(1)
{
input = getchar();
if(input == option_a)
{
printf("We're on.!\n");
}
else if(input == option_b)
{
printf("Off we go.\n");
}
else
{
printf("Excuse me, but I didn't get that.\n");
}
}
return 0;
}
Simply option_a is me pressing the 1 key on keyboard, and option_b is key 2. When I press these keys, or any key for that matter, the application will always go to the "else" portion of the decision tree. Saying that, it's clear to me that, and I'll say with a lack of a better term/expression, that my application isn't seeing my input as the decimal number 1 or 2.
From the terminal, what is the structure of the data I'm sending to my application, or simply put, what does my 1or 2 "look" like to my application?
When you are taking input with getchar() you are getting an char value. But you are comparing it with an integer. Instead of comparing with the integer, you can compare the input with corresponding characters. For example, use
const char option_a = '1';
const char option_b = '2';
I believe you want to find the American Standard Code for information interchange(ASCII) table. 0 = 48, 1 = 49, 2 = 50,...I had the same problem while working with arduino’s serial monitor, and it should all be covered by the same standard.
I have been developing a very simple text game using Objective C and Xcode. It is almost done but I am having a problem, the scanf method stops the loop and asks for user input while I need the computer to be running the rest of the loop, the solution I came up with was running two while loops at the same time, one being the logic loop and another being a loop for user input.
I have been doing my research and it looks like using threads are the way to go, I just have not found a tutorial that will break it down for a n00b in Objective C (I am decent in java, I just have never worked with threads). If anybody could explain them or link me to a very broken down tutorial that would be great. Or if anybody has another idea I am open to anything else.
Necessary Code (The scanf I am having a problem with has asterisks on the line):
while(running != 0)
{
if(gameState == 1)
{
if(timeToGenerateNum == true)
{
while(randNumber < 10000000)
{
randNumber = arc4random() % 100000000;
}
NSLog(#"%i", randNumber);
timeToGenerateNum = false;
}
else
{
while(time <= 2500)
{
NSLog(#"Testing");
time++;
******************scanf("%i", &userNum);************************
if(userNum == randNumber)
{
score += time;
time = 0;
timeToGenerateNum = true;
}
}
NSLog(#"Game Over! Your score was %i!", score);
running = 0;
}
}
else if(gameState == 2)
{
NSLog(#"To play, simply type in the number that appears on the screen.");
NSLog(#"But be careful, you only have a short amount of time before GAME OVER!");
NSLog(#"The quicker you type in the number the more score you get!");
NSLog(#"Are you ready to start, if so type '1' and press enter!");
scanf("%i", &gameState);
}
}
You're going to have to learn a bit about BSD (Unix, Linux) input/output to pull this off: replace your call to scanf with a non-blocking function you write to acquire input from the user's keyboard.
This function should immediately return whatever the user typed, or immediately return with a zero character count if she didn't type anything.
Read up on the select(2) system call, and keep in mind that keyboard input (standard input) is the first file descriptor, file descriptor zero.
Coming from an extremely spoiled family upbringing (turbo pascal, python, ruby) I'm a bit puzzled when it comes to doing all the household chores myself.
Yesterday was one of these days where I just did not find myself a solution. I had to check whether a value matches one of some other values.
x = some_function_return_value();
if x in (1,4,17,29,35):
That's how I used to write it. Now with Objective-C I obviously can't do that. And I searched the old google, but found no answer, and the old manual, and nothing there, so how do you do this in Objective-C, without doing something cranky like the following?
if (x == 1 || x == 4 || x == 17 || x == ...) {
Edited: in this case it is an (int), I know for NSArray and NSString there are methods for this
If it's about integer values, you can use switch:
switch (x) {
case 1:
case 4:
case 17:
case 29:
case 35:
do_something();
break;
}
Do not forget that in C/C++/Objective-C, the cases fall through to the next by default. You need to add break; statements to prevent that.
For non-integer values, you have to do long if statements with a lot of repetition as C doesn't provide syntactic sugar or features that many scripting languages have to abbreviate this.
Another way would be for example to prepare an array and then do:
if ([myArray containsObject:[NSNumber numberWithInteger:x]])
or even better, use an NSSet for that. This will work for most objects, for example it will also work with strings.
There is a fast enumeration syntax in objective C that uses "in" to loop over collections, however given it requires converting your int values to NSNumbers, it's probably easier to use C here
BOOL success = NO;
int size = 5
NSInteger numbers[size] = {1,4,17,29,35};
for (int i = 0; i < size; i++) {
if (yourValue == numbers[i]) {
success = YES;
break;
}
}
if (success) {
/* do your stuff */
}
admittedly not as nice as python...
Here's my silly program of the day:
bool int_exists_in_array(const int n, const int a[], const size_t elementCount) {
return (0 != elementCount) &&
(n == a[0] || int_exists_in_array(n, a + 1, elementCount - 1U));
}
so this:
if x in (1,4,17,29,35):
becomes:
const int a[] = { 1, 4, 17, 29, 35 };
if (int_exists_in_array(x, a, sizeof(a)/sizeof(a[0]))) {
...
}
You can use NSSet in addition with NSValue.
I'm trying to use the systemLock() to lock the device when the getSpeed() returns a value greater than 20 m/s.
public void locationUpdated(LocationProvider provider, Location location)
{
if(location.isValid())
{
float speed = location.getSpeed();
// Information to be displayed on the device
StringBuffer sb = new StringBuffer();
sb.append("\n");
sb.append("Speed : ");
sb.append(speed);
sb.append(" m/s");
if(speed < 20){
appMan = ApplicationManager.getApplicationManager();
appMan.lockSystem(true);
}else{
}
MyApp.this.updateLocationScreen(sb.toString());
}
}
I have a RichTextField and I can use the .settext() successfully in the if/else statement to change the RichTextField's text so I must be using the lockSystem() wrong.
Edit
if(speed > 20 || Double.isNaN(speed)){
requestForeground();
appMan = ApplicationManager.getApplicationManager();
appMan.lockSystem(true);
}else{
}
The first thing that comes to the eyes is:
to lock the device when the getSpeed() returns a value greater than 20 m/s.
and
if (speed < 20) {
appMan = ApplicationManager.getApplicationManager();
appMan.lockSystem(true);
}
From the docs on Location
public float getSpeed()
Returns:
the current ground speed in m/s for
the terminal or Float.NaN if the speed is not known
In Java, any comparison against Float.NaN will return false, so your lock screen code block won't execute if your device is returning NaN as the speed. You might want to add Double.isNaN(speed) to your condition.