Re: What is the best way to get just the duplicates from an array?

This is a FAQ. Please see perldoc -q duplicate or perlfaq4, How can I remove duplicate elements from a list or array. Obviously you want to keep just the duplicates instead of removing them, but doing so is left as an exercise.

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Re^2: What is the best way to get just the duplicates from an array? by wenD (Beadle) on Jul 27, 2007 at 15:56 UTC
Thanks! The perlfaq4 example (with the ! for unique removed) is the one that I'll use from now on. `my %seen = (); my @duplicates = grep { $seen{ $_ }++ } @array;` [download]	[reply] [d/l]
Re^3: What is the best way to get just the duplicates from an array? by ikegami (Patriarch) on Jul 27, 2007 at 16:09 UTC
That won't work. If there's three of the same thing, it will print the duplicate twice. That's why I used `==` in my earlier post instead of (an implied) `>`.	[reply] [d/l] [select]