Credit Card validation with Jquery

Question

I\'m trying to validate credit card numbers with jQuery but i dont want to use the validation plugin , is there any other plugin for doing this?

Answer 1

I recommend you to use Regular expression... You can check my repository I have a code snippet to validate Visa, Master card, Discovery, american express and the Security code

https://github.com/leojavier/RegexCollection

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Remember... just because you limit the amount of digits doesn't mean it will be right.

for instance:
- All Visa card numbers start with a 4. New cards have 16 digits.
- All MasterCard numbers start with the numbers 51 through 55. All have 16 digits. and so on...

The index.html is a sample, to show you how you can use it! Feel free to write me if you have any questions :)

Answer 2

If you want to be certain that its a valid card number, you'll need to check much more than the Luhn digit.

The Luhn digit is only intended for checking transposition errors, and can easily be spoofed with numbers such as 22222222222222222

The first six digits of the card number should be checked. These digits are known as the issuer identification number, and can be used to ensure that the number is within a recognised range. Unfortunately you'll struggle to find a comprehensive list of IIN's, not least because issuers are constantly adding and removing ranges. Wikipedia has a very basic overview though: Bank card number

If you can determine the card type from the IIN, you can then have a stab at validating the length of the number also.

Unless you have very good reason, its much easier to use something like a validation plug-in.

Answer 3

http://en.wikipedia.org/wiki/Luhn_algorithm

You could minimize this below into a very small footprint in your code.

function isCreditCard( CC )
 {                        
      if (CC.length > 19)
           return (false);

      sum = 0; mul = 1; l = CC.length;
      for (i = 0; i < l; i++)
      {
           digit = CC.substring(l-i-1,l-i);
           tproduct = parseInt(digit ,10)*mul;
           if (tproduct >= 10)
                sum += (tproduct % 10) + 1;
           else
                sum += tproduct;
           if (mul == 1)
                mul++;
           else
                mul--;
      }
      if ((sum % 10) == 0)
           return (true);
      else
           return (false);
 }