ChallengeProjectCreditCardChecker.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]
const valid6 =   [4, 5, 3, 9, 6, 8, 9, 8, 8, 7, 7, 0, 5, 7, 9, 8]

// 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,valid6, invalid1, invalid2, invalid3, invalid4, invalid5, mystery1, mystery2, mystery3, mystery4, mystery5]

// Identify the credit card companies
const creditCompanies = {
    3:'Amex (American Express)',
    4: 'Visa',
    5: 'Mastercard',
    6: 'Discover'
}

// Add your functions below:

const sumAll = arrOfNums => {
    return arrOfNums.reduce((acc,newNum)=>acc + newNum)
}

const multyplayArrByTwo = arr => arr.map(num=> num * 2)

const decrementItFrom9 = arr => arr.map(num => {
    if (num > 9){
        return num - 9
    }else{
        return num
    }
})

const reverseAnArray = arr => arr.reverse()

const evenArrIndex = arr =>{
    let evenIndexNum = [];
    for (let i = 0; i < arr.length; i++){
        if (i % 2 === 0){
            evenIndexNum.push(arr[i])
        }
    }
    return evenIndexNum
}

const oddArrIndex = arr => {
    let oddIndexNum = [];
    for (let i = 0; i < arr.length; i++){
        if (i % 2 !== 0){
            oddIndexNum.push(arr[i])
        }
    }
    return oddIndexNum
}


// Step one reverse an array
// const arrayReversed = reverseAnArray(test)
// console.log(arrayReversed, 'passed')

// Step two select even index from an reversed array.
// const evenIndexSelected = evenArrIndex(arrayReversed)
// console.log(evenIndexSelected, evenIndexSelected.length, 'passed')

// Step three Select odd index from an reversed array
// const oddIndexSelected = oddArrIndex(arrayReversed)
// console.log(oddIndexSelected, oddIndexSelected.length, 'passed')

// Step four multiplay each number withen evenIndexSelected by 2
// const multyByTwo = multyplayArrByTwo(oddIndexSelected)
// console.log(multyByTwo, 'passed')

// Step five check if any number withen multyByTwo is greater than 9
// If so decrement it from 9
// const decrementItList = decrementItFrom9(multyByTwo)
// console.log(decrementItList, 'passed')

// Step six sum array one and two and then modulo 10 if the result is zero that mean the cridet is valid otherwise is not valid
// console.log((sumAll(decrementItList) + sumAll(evenIndexSelected)) % 10 )

const validateCred = arr => {
    let arrayReversed = reverseAnArray(arr)
    const evenIndexSelected = evenArrIndex(arrayReversed)
    const oddIndexSelected = oddArrIndex(arrayReversed)
    const multyByTwo = multyplayArrByTwo(oddIndexSelected)
    const decrementItList = decrementItFrom9(multyByTwo)
    const sumTwoList = sumAll(decrementItList) + sumAll(evenIndexSelected)
    arrayReversed = reverseAnArray(arr)
    if (sumTwoList % 10 === 0){
        return true
    }
    return false
}

const idInvalidCardCompanies = (arr)=> {
    
    if(creditCompanies[arr[0]]) {
        return creditCompanies[arr[0]]
    }else{
        return 'Company not found'
    }

}


console.log('\nInvalids credit card \n')
for (numsArr of batch){
    if (!validateCred(numsArr)){
        let creditNum = numsArr.join('')
        console.log(`${idInvalidCardCompanies(numsArr)} with number |${creditNum}| is not valid!`)
    }
}

console.log('\nValids credit card \n')
for (numsArr of batch){
    // console.log(numsArr)
    if (validateCred(numsArr)){
        let creditNum = numsArr.join('')
        console.log(`${idInvalidCardCompanies(numsArr)} with number |${creditNum}| is valid!`)
    }
}