luhn

来源： https://stackoverflow.com/questions/40688156/python-credit-card-validation

问题 Does anyone have a library or JavaScript snippet to validate the check digit of credit cards before the user hits Submit? 回答1: The jQuery Validation Plugin has a method for validating credit card numbers. There are other specific scripts: JavaScript Credit Card Validation Function Credit Card Validation Most of them use the Luhn algorithm. 回答2: Probably OP doesn't even follow this thread anymore but this may be helpful for someone else: http://jquerycreditcardvalidator.com It checks the card

问题 I used to be coding with C#, I'm learning C++ at UOW currently. There's this assignment that im supposed to verify a credit card whether its valid via modulus 10 (LUHN formula) However I didn't manage to get the correct answer as displayed/required by the lecturer. The below are my C++ efforts for this assignment. Do advise, cheers. Problem1 - Loop error / infinite Problem2 - sum of 4 tokens (Digits) I got are incorrect I believe. Problem3 - Any advice to improve on this coding (without

问题 I tried to check the validation of credit card using Luhn algorithm, which works as the following steps: Double every second digit from right to left. If doubling of a digit results in a two-digit number, add up the two digits to get a single-digit number. 2 * 2 = 4 2 * 2 = 4 4 * 2 = 8 1 * 2 = 2 6 * 2 = 12 (1 + 2 = 3) 5 * 2 = 10 (1 + 0 = 1) 8 * 2 = 16 (1 + 6 = 7) 4 * 2 = 8 Now add all single-digit numbers from Step 1. 4 + 4 + 8 + 2 + 3 + 1 + 7 + 8 = 37 Add all digits in the odd places from

问题 def checksum(card_without_check): card_without_check = card_without_check[-1::-1] def numbers(string): return [int(x) for x in string] print(card_without_check) odd_numbers = numbers(card_without_check[0::2]) even_numbers = numbers(card_without_check[1::2]) odd_numbers = [x * 2 for x in odd_numbers] odd_numbers = [x - 9 if x > 9 else x for x in odd_numbers] print(even_numbers) print(odd_numbers) return sum(odd_numbers) + sum(even_numbers) def check(checksum, check): return checksum % 10 ==

问题 I was trying to implement the Luhn Formula in Python, here is my code: import sys def luhn_check(number): if number.isdigit(): last_digit = int(str(number)[-1]) reverse_sequence = list(int(d) for d in str(int(number[-2::-1]))) for i in range(0, len(reverse_sequence), 2): reverse_sequence[i] *= 2 for i in range(len(reverse_sequence)): if reverse_sequence[i] > 9: reverse_sequence[i] -= 9 sum_of_digits = 0 for i in range(len(reverse_sequence)): sum_of_digits += reverse_sequence[i] result =

问题 I am using following code to implement Luhn algorithm for credit card check in c# language but could not get the output to generate the check sum its showing validity: kindly help me.Thank you in advance public class Program { private static void Main(string[]creditcard) { int sum = 0, d; string num ="7992739871"; int a = 0; for (int i = num.Length - 2; i >= 0; i--) { d = Convert.ToInt32(num.Substring(i, 1)); if (a % 2 == 0) d = d * 2; if (d > 9) d -= 9; sum += d; a++; } if ((10 - (sum % 10)

问题 Having a little issue with my code to see if a credit card number adheres to the Luhn Algorithm. The code is returning true when the Credit Card is divisible by 10, but also is returning true when the CC number is not divisible by 10. I have printed out the final sum to make sure the numbers were actually adding to the sum variable, and they seem to be.. Below is my code. I know it can be cleaner, but at this stage I would like to see it work first. def check_card c_num= [] sum=0 s_numbers=

问题 I've used the code from the link below to try and validate a credit card, however I'm not getting an alert when I submit a the wrong data in the field. Strip spaces before performing Luhn check my form is as follows: <form id="myform" method="post" action=""> <p>Select credit card: <select tabindex="11" id="CardType"> <option value="AmEx">American Express</option> <option value="CarteBlanche">Carte Blanche</option> <option value="DinersClub">Diners Club</option> <option value="Discover"

问题 I think I have computed Luhn algorithm correctly in Haskell: f1 :: Integer -> [Integer] f1 x = if x < 10 then [x] else (f1 (div x 10))++[mod x 10] f2 :: [Integer] -> [Integer] f2 xs = [(!!) xs (x - 1) | x <- [1..(length xs)] , even x] f3 :: [Integer] -> [Integer] f3 xs = if mod (length xs) 2 /= 0 then (f2 xs) else (f2 (0:xs)) f4 :: [Integer] -> [Integer] f4 xs = map (*2) (f3 xs) f5 :: [Integer] -> [[Integer]] f5 xs = map f1 xs f6 :: [[Integer]] -> [Integer] f6 [] = [] f6 (xs : xss) = xs++(f6