How do I pull out unique values in a multidimentional array

xorl has asked for the wisdom of the Perl Monks concerning the following question:

This is what I have:

@array = ([a,0,b],[c,1,d],[d,1,e],[f,2,h];
[download]

I only care about the 2nd field. I want all of the unique values. In other words I want to get 0, 1, and 2. In the script I have they will always be sorted by the 2nd field, so there should be no need to do a sort. Any suggestions? Thanks

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Re: How do I pull out unique values in a multidimentional array by dragonchild (Archbishop) on Jun 28, 2001 at 23:15 UTC
`my %unique_values; $unique_values{$_->[1]}++ for @array; print "Key $_\n" foreach keys %unique_values;` [download]	[reply] [d/l]
Re: How do I pull out unique values in a multidimentional array by dimmesdale (Friar) on Jun 28, 2001 at 23:53 UTC
This isn't tested, but it should do the trick `map { $results[$k++] = $_->[1] if !$seen{$_->[1]}++ } @array;` [download]	[reply] [d/l]
Re: How do I pull out unique values in a multidimentional array by repson (Chaplain) on Jun 29, 2001 at 11:31 UTC
If you are willing to rely on the values being sorted and don't want to create a hash of the values like the other solutions you could do something like this. `my @unique; for (@array) { push @unique, $_->[1] unless $unique[$#unique] == $_->[ +1] }` [download]	[reply] [d/l]
Re: How do I pull out unique values in a multidimentional array by dragonchild (Archbishop) on Jun 28, 2001 at 23:18 UTC
Sorry about the above - forgot the <code> tags. `my %unique_values; $unique_values{$_->[1]}++ for @array; print "Key $_\n" foreach keys %unique_values;` [download] Originally posted as a Categorized Answer.	[reply] [d/l]