To find elements that are in one array but not in another, there is a nice loopless solution from the Perl Cookbook which uses the delete function: 
my %seen;
@seen{ @original_1 } = ();
delete @seen{ @original_2 };
my @original_1_only = keys %seen;

[download]
Of course there is also a loopy solution, should you prefer it: 
my %seen;
my @original_1_only;
@seen{ @original_2 } = ();
foreach (@original_1) {
    push(@original_1_only, $_) unless exists $seen{$_};
};

[download]
Stick with these.

Ciao,
Emanuele.

In reply to Re: Extracting elements in one array but not in another by emazep
in thread Extracting elements in one array but not in another by august3

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