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@CodingCyrus
Created Aug 6, 2022
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Challenge Project: Credit Card Checker
// 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) => {
let sum = 0;
if (array.length % 2 == 0) {
for (let i = array.length - 2; i >= 0; i--) {
if (i % 2 == 0) {
let num = array[i] * 2;
if (num > 9) {
let newNum = num - 9;
sum += newNum;
} else {
sum += num;
}
} else {
sum += array[i];
}
}
} else {
for (let i = array.length - 2; i >= 0; i--) {
if (i % 2 != 0) {
let num = array[i] * 2;
if (num > 9) {
let newNum = num - 9;
sum += newNum;
} else {
sum += num;
}
} else {
sum += array[i];
}
}
}
sum = sum + array[array.length - 1];
if (sum % 10 == 0) {
return true;
} else {
return false;
}
};
// Test functions:
console.log(validateCred(valid1)); // Should print true
console.log(validateCred(invalid1)); // Should print false
const findInvalidCards = (nestedArray) => {
let invalidCards = [];
for (let array of nestedArray) {
if (!validateCred(array)) {
invalidCards.push(array);
}
}
return invalidCards;
};
// Test function
console.log(findInvalidCards([valid1, valid2, valid3, valid4, valid5])); // Shouldn't print anything
console.log(
findInvalidCards([invalid1, invalid2, invalid3, invalid4, invalid5])
); // Should print all of the numbers
console.log(findInvalidCards(batch)); // Test what the mystery numbers are
const idInvalidCardCompanies = (invalidCards) => {
const companies = [];
for (let cardNumber in invalidCards) {
let company = "";
switch (invalidCards[cardNumber][0]) {
case 3:
company = "Amex (American Express)";
break;
case 4:
company = "Visa";
break;
case 5:
company = "Mastercard";
break;
case 6:
company = "Discover";
break;
default:
console.log("Company not found");
}
if (!companies.includes(company)) {
companies.push(company);
}
}
return companies;
};
console.log(idInvalidCardCompanies([invalid1])); // Should print['visa']
console.log(idInvalidCardCompanies([invalid2])); // Should print ['mastercard']
console.log(idInvalidCardCompanies(batch)); // Find out which companies have mailed out invalid cards
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