A script to detect a valid credit card, just dial into the terminal the 16 digit number you want to verify and run the code to check it's authenticity Steps to use the code : STEP 1 :- Download the files as a zip. STEP 2 :- Open the MainCode.cpp into your preferred IDE STEP 3 :- Download gcc compiler and feed it's path into your environment variable STEP 4 :- Run the code, type the credit card number into your terminal and let the code do it's thing This code run on the principle set by Luhn's Algorithm which actually is an international standard to produce the numbers mentioned on one credit cards' For better understanding refer to following to get ins about the algorithm working https://www.geeksforgeeks.org/luhn-algorithm/