Luhn test of credit card numbers
Solutions
Solution 1 (Click to Show/Hide)
function luhnTest(str) {
var luhnArr = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9];
var counter = 0;
var incNum;
var odd = false;
var temp = String(str).replace(/[^\d]/g, '');
if (temp.length == 0) return false;
for (var i = temp.length - 1; i >= 0; --i) {
incNum = parseInt(temp.charAt(i), 10);
counter += (odd = !odd) ? incNum : luhnArr[incNum];
}
return counter % 10 == 0;
}