That's bad for readability (harder for the user to figure out which one of his cards was used), and it's bad security (since the number could be obtained over time or if multiple retailers did this). And of course, there's are times when two, one and even no digits are hidden.

In reply to Re^2: Golf: Replacing part of a string with "*" by ikegami
in thread Golf: Replacing part of a string with "*" by kwaping

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