Sha256: 1ab7c113b4cf437bcb4f06a80cab93183d49fe1f21ba37131531a5175562b56a
Contents?: true
Size: 1.32 KB
Versions: 72
Compression:
Stored size: 1.32 KB
Contents
export default class Luhn {
constructor(number) {
this.checkDigit = number % 10;
this.addends = Luhn.calculateAddends(number);
this.checksum = Luhn.calculateChecksum(this.addends);
this.valid = Luhn.determineIfValid(this.checksum);
}
static calculateAddends(number) {
const numberAsString = '' + number + '',
numbers = [...numberAsString],
addends = [];
for (let i = 0; i < numbers.length; i++) {
const index = numbers.length - 1 - i;
let 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();
}
static calculateChecksum(numbers) {
let sum = 0;
for (let i = 0; i < numbers.length; i++) {
sum += numbers[i];
}
return sum;
}
static determineIfValid(sum) {
return sum % 10 === 0;
}
static create(number) {
let finalNumber = number * 10,
luhnNumber = new Luhn(finalNumber),
index = 0;
while (!luhnNumber.valid) {
finalNumber = number * 10 + index;
luhnNumber = new Luhn(finalNumber);
if (luhnNumber.valid) {
break;
}
index += 1;
}
return finalNumber;
}
}
Version data entries
72 entries across 72 versions & 1 rubygems