43 lines
944 B
JavaScript
43 lines
944 B
JavaScript
|
"use strict";
|
||
|
|
||
|
Object.defineProperty(exports, "__esModule", {
|
||
|
value: true
|
||
|
});
|
||
|
exports.default = isLuhnNumber;
|
||
|
|
||
|
var _assertString = _interopRequireDefault(require("./util/assertString"));
|
||
|
|
||
|
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
|
||
|
|
||
|
function isLuhnNumber(str) {
|
||
|
(0, _assertString.default)(str);
|
||
|
var sanitized = str.replace(/[- ]+/g, '');
|
||
|
var sum = 0;
|
||
|
var digit;
|
||
|
var tmpNum;
|
||
|
var shouldDouble;
|
||
|
|
||
|
for (var i = sanitized.length - 1; i >= 0; i--) {
|
||
|
digit = sanitized.substring(i, i + 1);
|
||
|
tmpNum = parseInt(digit, 10);
|
||
|
|
||
|
if (shouldDouble) {
|
||
|
tmpNum *= 2;
|
||
|
|
||
|
if (tmpNum >= 10) {
|
||
|
sum += tmpNum % 10 + 1;
|
||
|
} else {
|
||
|
sum += tmpNum;
|
||
|
}
|
||
|
} else {
|
||
|
sum += tmpNum;
|
||
|
}
|
||
|
|
||
|
shouldDouble = !shouldDouble;
|
||
|
}
|
||
|
|
||
|
return !!(sum % 10 === 0 ? sanitized : false);
|
||
|
}
|
||
|
|
||
|
module.exports = exports.default;
|
||
|
module.exports.default = exports.default;
|