Codecademy export

main.js

// All valid credit card numbers
const valid1 = [4, 5, 3, 9, 6, 7, 7, 9, 0, 8, 0, 1, 6, 8, 0, 8]
const valid2 = [5, 5, 3, 5, 7, 6, 6, 7, 6, 8, 7, 5, 1, 4, 3, 9]
const valid3 = [3, 7, 1, 6, 1, 2, 0, 1, 9, 9, 8, 5, 2, 3, 6]
const valid4 = [6, 0, 1, 1, 1, 4, 4, 3, 4, 0, 6, 8, 2, 9, 0, 5]
const valid5 = [4, 5, 3, 9, 4, 0, 4, 9, 6, 7, 8, 6, 9, 6, 6, 6]

// All invalid credit card numbers
const invalid1 = [4, 5, 3, 2, 7, 7, 8, 7, 7, 1, 0, 9, 1, 7, 9, 5]
const invalid2 = [5, 7, 9, 5, 5, 9, 3, 3, 9, 2, 1, 3, 4, 6, 4, 3]
const invalid3 = [3, 7, 5, 7, 9, 6, 0, 8, 4, 4, 5, 9, 9, 1, 4]
const invalid4 = [6, 0, 1, 1, 1, 2, 7, 9, 6, 1, 7, 7, 7, 9, 3, 5]
const invalid5 = [5, 3, 8, 2, 0, 1, 9, 7, 7, 2, 8, 8, 3, 8, 5, 4]

// Can be either valid or invalid
const mystery1 = [3, 4, 4, 8, 0, 1, 9, 6, 8, 3, 0, 5, 4, 1, 4]
const mystery2 = [5, 4, 6, 6, 1, 0, 0, 8, 6, 1, 6, 2, 0, 2, 3, 9]
const mystery3 = [6, 0, 1, 1, 3, 7, 7, 0, 2, 0, 9, 6, 2, 6, 5, 6, 2, 0, 3]
const mystery4 = [4, 9, 2, 9, 8, 7, 7, 1, 6, 9, 2, 1, 7, 0, 9, 3]
const mystery5 = [4, 9, 1, 3, 5, 4, 0, 4, 6, 3, 0, 7, 2, 5, 2, 3]

// An array of all the arrays above
const batch = [valid1, valid2, valid3, valid4, valid5, invalid1, invalid2, invalid3, invalid4, invalid5, mystery1, mystery2, mystery3, mystery4, mystery5]


// Add your functions below:

const validateCred = card => {
    let array = card.map( x => x);
    let sum = array.pop();
    let double = 1;
    let digits = array.reduceRight( (total, digit) => {
        if (double%2) {
            digit = digit*2;
            if(digit > 9) {
                digit -= 9;
            }
        }
        double += 1;
        return total + digit;
    }, 0);
    
    sum += digits;

    return(!(sum%10));
}

const findInvalidCards = (array) => {
    const invalidCards = [];

    array.forEach( card => {
        if (validateCred(card) === false) {
            invalidCards.push(card);
        }
    })

    return invalidCards;
}

const idInvalidCardCompanies = array => {
    const invalidCardCompanies = [];

    array.forEach( card => {
        let company = '';

        switch (card[0]) {
            case 3:
                company = 'Amex (American Express)';
                break;
            case 4:
                company = 'Visa';
                break;
            case 5:
                company = 'Mastercard';
                break;
            case 6:
                company = 'Discover';
                break;
            default:
                company = 'Company not found';
        }

        if (!invalidCardCompanies.includes(company)) {
            invalidCardCompanies.push(company);
        }
    })

    return invalidCardCompanies;
}

console.log(idInvalidCardCompanies(findInvalidCards(batch)));