Inspired by the fact that 2013 is the first year since 1987 which has four unique digits, what's your best code to determine the number of unique digits in a number?

Here's what I ended up with, skipping the %unique method: 

$y = 2013;
($y = join('',sort(split(//,$y)))) =~ tr/0-9//s;
print "unique digits: " .  length($y) . $/;

[download]

I'm sure there's something smarter.

In reply to Golf for unique digits by Cody Fendant

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