Contents

class Luhn {
    static valid(value: string): boolean {
        const numbers = value.replace(/\s/g, '')
        const digits = [...numbers]

        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 Luhn

Version data entries

63 entries across 63 versions & 1 rubygems

Version	Path
trackler-2.2.1.180	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.179	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.178	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.177	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.176	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.175	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.174	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.173	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.172	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.171	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.170	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.169	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.167	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.166	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.165	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.164	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.163	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.162	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.161	tracks/typescript/exercises/luhn/luhn.example.ts
trackler-2.2.1.160	tracks/typescript/exercises/luhn/luhn.example.ts