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 = (arr) => {
    cloneArr = [...arr];
    cloneArr.reverse();
    let result = [];
    cloneArr.forEach((elem, idx) => {
        if(idx % 2 === 0){
            result.push(elem);
        } else {
            if((elem * 2) > 9){
                result.push(elem * 2 - 9)
            } else (
                result.push(elem * 2)
            )
        }
    })
    let total = result.reduce((acu, cur) => acu + cur);
    if(total % 10 === 0){
        return true;
    } else {
        return false;
    }

}

const findInvalidCards = (arr) => {
    let invalid = [];
    arr.forEach(elem => {
        if(!validateCred(elem)){
            invalid.push(elem);
        }

    })
    return invalid;
}

const idInvalidCardCompanies = (arr) => {
    let firstDigit = [];
    let names = [];
    arr.forEach(elem => {firstDigit.push(elem[0])});
    if(firstDigit.includes(3)){
        names.push('Amex (American Express)');
    }
    if(firstDigit.includes(4)){
        names.push('Visa');
    }
    if(firstDigit.includes(5)){
        names.push('Mastercard');
    }
    if(firstDigit.includes(6)){
        names.push('Discover');
    }
    if(names.length !== 0){
        return(names);
    } else {
        console.log('Company not found');
    }
}

DId you remember to remember the doubles from the push of idInvalidCardCompanies?

Beside that... Well done!!!