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What is the best way to validate a credit card in PHP?
I am thinking of making an online shopping cart, using credit card validation. My question is, how is the entered credit card going to be validated? I am new to credit card validation, and I was wondering if there is a database with valid credit card numbers? (I know you can do this through PayPal). I also know there is an algorithm to check if the credit card is valid. And after checking the validation how is the charge gonna be made to that credit card and where do you get the money from? Excuse me if my question(s) are naive