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 = (array) => {
    array.reverse() // inverter array
    //console.log(array)

    let temporaryArray = [];

    // tag hvert tal i rækken og gang kun hvert anndet tal med 2
    // hvis tallet gange med 2 er over 9 lægges de to tal sammen eks.   13 = 4.
    // derefter lægges tallet i midlertidig array.
    for (let i = 0; i < array.length; i ++){
        if (i % 2 === 1){
            let doubleUp = array[i] * 2;
            if (doubleUp > 9){
                doubleUp -= 9;
            };
            temporaryArray.push(doubleUp);
        } else {
            temporaryArray.push(array[i]);
        }; // if
    }; // for loop

    // tag hvert tal i midlertidig array og læg dem sammen.
    let sum = 0;
    temporaryArray.forEach(tal => {
        sum += tal;  
    }); // forEach funktion

    if (sum % 10 == 0){
        return "Valid"
    } else {
        return "Invalid"
    }
    //console.log(sum)
    //console.log(temporaryArray)
};

// 4
const findInvalidCards = (nestedArray) => {
    const invalidCards = [];
    nestedArray.forEach(value => {
        if (validateCred(value) === "Invalid"){
            invalidCards.push(value.reverse())
        };

    });
    return invalidCards
    
};

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

// 5
const idInvalidCardCompanies = (invalidNumbersArray) => {
    
    const companies = []; // companies that have mailed out

    invalidNumbersArray.forEach(element => {
        if (element[0] === 3){
            if (companies.indexOf("Amex (American Express)") >= 0){
                return true;
            } else {
                companies.push("Amex (American Express)");
            };
        }; // if 

        if (element[0] === 4){
            if (companies.indexOf("Visa") >= 0){
                return true;
            } else {
                companies.push("Visa");
            };
        };

        if (element[0] === 5){
            if (companies.indexOf("Mastercard") >= 0){
                return true;
            } else {
                companies.push("Mastercard");
            };
        };

        if (element[0] === 6){
            if (companies.indexOf("Discover") >= 0){
                return true;
            } else {
                companies.push("Discover");
            };
        } else {
            console.log("Company not found");
        };
    }); // forEach metode slut

    return companies;
};

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