Sha256: 8c19e4cf656cbee7d4d204f8b076e8c855b47740c0554fab793e4de20aa0df63
Contents?: true
Size: 1.34 KB
Versions: 72
Compression:
Stored size: 1.34 KB
Contents
'use strict';
function Luhn(number) {
this.checkDigit = number % 10;
this.addends = this.calculateAddends(number);
this.checksum = this.calculateChecksum(this.addends);
this.valid = this.determineIfValid(this.checksum);
}
Luhn.prototype = {
calculateAddends: function(number) {
var numberAsString = '' + number + '';
var numbers = numberAsString.split('');
var addends = [];
for (var i = 0; i < numbers.length; i++) {
var index = numbers.length - 1 - i;
var currentAddend = parseInt(numbers[index], 10);
if ((i + 1) % 2 === 0) {
currentAddend = currentAddend * 2;
if (currentAddend > 10) {
currentAddend = currentAddend - 9;
}
}
addends.push(currentAddend);
}
return addends.reverse();
},
calculateChecksum: function(numbers) {
var sum = 0;
for (var i = 0; i < numbers.length; i++) {
sum += numbers[i];
}
return sum;
},
determineIfValid: function(sum) {
return (sum % 10 === 0);
}
};
Luhn.create = function(number) {
var finalNumber = number * 10;
var luhnNumber = new Luhn(finalNumber);
var index = 0;
while(!luhnNumber.valid) {
finalNumber = number * 10 + index;
luhnNumber = new Luhn(finalNumber);
if (luhnNumber.valid) { break; }
index += 1;
}
return finalNumber;
};
module.exports = Luhn;
Version data entries
72 entries across 72 versions & 1 rubygems