Sha256: b54628e344abb8b6965827f30178b7d9a2c78f0021f2d5e6b5610f35d00f6706
Contents?: true
Size: 634 Bytes
Versions: 139
Compression:
Stored size: 634 Bytes
Contents
function isValid(number) {
number = number.replace(/\s/g, '');
const digits = [...number];
const sum = digits
// convert to integers
.map(d => parseInt(d, 10))
// double even positions (odd indexes)
.map((d, i) => {
if (i % 2 !== 0) {
return d * 2;
}
return d;
})
// limit to digits less than 10
.map(d => {
if (d > 9) {
return d - 9;
}
return d;
})
// sum all digits
.reduce((d, acc) => d + acc, 0);
return sum > 0 && sum % 10 === 0;
}
export default class Luhn {
constructor(number) {
this.valid = isValid(number);
}
}
Version data entries
139 entries across 139 versions & 1 rubygems