Credit Card Checker Challenge Project (JavaScript)

Hello All,

This is still very much a work in progress. I am still trying to make sure I understand what I actually coded. Any feedback would be greatly appreciated.

Codepen has been updated. It should match the below Gist

// 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: let isValid = false; function validateCred(arr) { let copyArr = Array.isArray(arr) ? arr.slice().reverse() : arr.toString().split("").reverse().map(Number); // Check if arr is an array, if not convert it to an array let sum = 0; let isEven = false; for (let i = 0; i < copyArr.length; i++) { let digit = parseInt(copyArr[i]); if (isEven) { digit *= 2; if (digit > 9) { digit -= 9; } } sum += digit; isEven = !isEven; } isValid = sum % 10 === 0; console.log( `The card number: ${arr} has been validated. Is it valid? Result: ${isValid}` ); return arr; } function findInvalidCards(batch) { let invalidCards = []; for (let i = 0; i < batch.length; i++) { validateCred(batch[i]); // Run validateCred() to update isValid if (!isValid) { invalidCards.push(batch[i]); } } console.log("The below card numbers are not valid:"); return invalidCards; } function idInvalidCardCompanies(invalidNumbers) { let companies = []; // Convert single array or string to an array of arrays if (!Array.isArray(invalidNumbers[0])) { invalidNumbers = [invalidNumbers]; } else if (typeof invalidNumbers === "string") { invalidNumbers = [invalidNumbers.split("").map(Number)]; } for (let i = 0; i < invalidNumbers.length; i++) { let firstDigit = invalidNumbers[i][0]; switch (firstDigit) { case 3: if (!companies.includes("Amex")) { companies.push("Amex"); console.log(invalidNumbers[i][0]); } break; case 4: if (!companies.includes("Visa")) { companies.push("Visa"); console.log(invalidNumbers[i][0]); } break; case 5: if (!companies.includes("Mastercard")) { companies.push("Mastercard"); console.log(invalidNumbers[i][0]); } break; case 6: if (!companies.includes("Discover")) { companies.push("Discover"); console.log(invalidNumbers[i][0]); } break; default: console.log(invalidNumbers[i][0]); console.log("Company not found"); } } return companies; } console.log(validateCred(invalid1)); console.log(findInvalidCards(batch)); // console.log(idInvalidCardCompanies(findInvalidCards(batch))); // console.log(idInvalidCardCompanies(validateCred(invalid2))); // console.log(idInvalidCardCompanies(invalid2)); // console.log(idInvalidCardCompanies(validateCred(invalid1))); // console.log(validateCred(valid1)); // console.log(validateCred(invalid1));