Contents

class ISBN {
    isbn: string

    constructor(isbn: string) {
        this.isbn = isbn.replace(/-/g, '')
    }

    isValid() {
        if (!this.isbn.match(/^(\d{9}[\dxX])$/)) {
            return false
        }

        const digits = [...this.isbn]
        if (digits[9].match(/[xX]/)) {
            digits[9] = '10'
        }

        const sum = digits.reduce((acc, value, index) => acc + ((10 - index) * parseInt(value, 10)), 0)

        return sum % 11 === 0
    }
}

export default ISBN

Version data entries

59 entries across 59 versions & 1 rubygems

Version	Path
trackler-2.2.1.159	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.158	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.157	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.156	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.155	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.154	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.153	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.152	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.151	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.150	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.149	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.148	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.147	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.146	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.145	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.144	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.143	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.142	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.141	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts
trackler-2.2.1.140	tracks/typescript/exercises/isbn-verifier/isbn-verifier.example.ts