Credit Card Validator
In this lab, you will be implementing the validateCreditCard
method in Java. The method should utilize the Luhn algorithm to determine the validity of a given credit card number.
Instructions
-
Implement
validateCreditCard
method:- Open the
Main
class. - Implement the
validateCreditCard
method using the provided signature:public static boolean validateCreditCard(String creditCardNumber) { // Your implementation here }
- Your method should return
true
for a valid credit card number.
- Open the
-
Handle invalid credit card numbers:
- Extend the
validateCreditCard
method to handle invalid credit card numbers. - Update the method to return
false
when an invalid credit card number is provided. - Ensure the method still returns
true
for a valid credit card number.
- Extend the
Luhn Algorithm
The Luhn algorithm is a simple checksum formula that is used to validate various identification numbers, including credit card numbers. Here's a brief overview:
- Starting from the rightmost digit, double every second digit.
- If doubling results in a two-digit number, add the digits together.
- Sum all the digits in the credit card number.
- If the total sum is a multiple of 10, the credit card number is valid.
Expected Output
- Challenge 1: Your
validateCreditCard
method should returntrue
for a valid credit card number. - Challenge 2: The method should return
false
for an invalid credit card number.
Tips
- Pay attention to the Luhn algorithm logic.
- Test your code thoroughly with different credit card numbers.
Challenges
Challenge 1: Implement the validateCreditCard
method
Implement the validateCreditCard
method in the Main
class in Java. The method should use the Luhn algorithm to check the validity of a given credit card number. The method should be defined as follows:
Ensure that the method returns true
for a valid credit card number.
Challenge 2: Handle invalid credit card numbers
Extend the validateCreditCard
method to handle invalid credit card numbers. Update the method to return false
when an invalid credit card number is provided. Ensure that the method still returns true
for a valid credit card number.