Created
March 25, 2013 13:43
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Credit card verification luhn checksum method
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/** | |
* Credit card verification luhn checksum method | |
*/ | |
function validateLuhnChecksum(cardNumber) { | |
if (cardNumber == 0) { return false; } | |
var sum = 0; | |
var mul = 1; | |
for (var x = cardNumber.length; x > 0 ; x--) { | |
var tproduct = parseInt(cardNumber.charAt(x - 1), 10) * mul; | |
if (tproduct >= 10) { | |
sum += (tproduct % 10) + 1; | |
} else { | |
sum += tproduct; | |
} | |
if (mul == 1) { | |
mul++; | |
} else { | |
mul--; | |
} | |
} | |
return ((sum % 10) == 0); | |
} |
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