Grepping on array

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

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Re: Grepping on array by diotalevi (Canon) on May 19, 2004 at 13:01 UTC
I would feel silly quoting the documentation. Execute `perldoc -q "difference of two arrays"` to see the standard answer. This is in perlfaq4, btw.	[reply] [d/l]
Re: Grepping on array by ctilmes (Vicar) on May 19, 2004 at 13:05 UTC
You can also use List::Compare to do this sort of thing: `my @arr1 = qw(a b c d e f g h); my @arr2 = qw(d a e); my @result = List::Compare->new(\@arr1, \@arr2)->get_Lonly; # @result = qw(b c f g h);` [download]	[reply] [d/l]
Re: Grepping on array by Abigail-II (Bishop) on May 19, 2004 at 13:01 UTC
`perldoc -q duplicate` [download] Abigail	[reply] [d/l]
Re: Grepping on array by herveus (Parson) on May 19, 2004 at 13:08 UTC
Howdy! `my %first = map { $_ => 1 } @arr2; @result = grep !exists $first{$_}, @arr1;` [download] %first is a hash whose keys are the distinct values in @arr2. The grep returns a list of the values in @arr1 that don't exist in %first, thus eliminating values in @arr2. yours, Michael	[reply] [d/l]
Re: Grepping on array by monkey_boy (Priest) on May 19, 2004 at 15:12 UTC
Set::scalar esp. usefull if your manipulations get more complex. I should really do something about this apathy ... but i just cant be bothered	[reply]
Re: Grepping on array by dragonchild (Archbishop) on May 19, 2004 at 14:07 UTC
This is a very basic set arithmetic question. (You're looking for the result set when subtracting @arr2 from @arr1.) ------ We are the carpenters and bricklayers of the Information Age. Then there are Damian modules.... sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon.* - flyingmoose I shouldn't have to say this, but any code, unless otherwise stated, is untested	[reply]


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