[eluser]untermensch[/eluser]
[quote author="Pygon" date="1194044896"]Mine is a concern for speed and enforcing standards, while allowing user input to be anything they want while still working. Should your function encounter a trailing hyphen, it would not work properly.[/quote]
Mate, have you even tried running your one above? The preg_replace is superfluos, and it strips out the hyphens, and assumes all CC numbers have 16 digits (they vary between 14 and 16).
Besides which, nobody asked about a CC number *validator*. It is assumed validation has already been done. The request was only to mask out all but the last 4 digits - so the trailing hyphen point is entirely moot (although your solution suffers from the same "problem").
[quote author="Pygon" date="1194044896"]"Simplicity", in the form of one-line functions, doesn't necessarily mean it is the best solution.[/quote]
Simplicity is readability.
[quote author="Pygon" date="1194044896"]Regex is great but takes it's toll on the CPU.[/quote]
Which makes me wonder why you have a redundant preg_replace
[quote author="Pygon" date="1194044896"]My function is limited in scope as to just masking any card that is entered (provided there are atleast 4 numbers)[/quote]
Which is exactly what the original poster asked for...
