An excellent click bait article for functional programming. For example, the brief talk of validators, why couldn't you just put the validator in the credit car

An excellent click bait article for functional programming. For example, the brief talk of validators, why couldn't you just put the validator in the credit card object? The credit card validator should only be used in the credit card object so the discussion about not being able to see it can be accessed by simply navigating to the classes that compose the credit card. Putting it in the constructor or other credit card methods fixes the not being forced aspect (when I look at the FP example, it looks like it's doing just this). And you can use the validator anywhere in the CC object.