Perl XML::LibXML searching for attribute value and counting occurences

Question

So this code works to match attribute values from one source to another with exactly the same structure so I haven't shown the xml. I just figured with how flash XML::LibXML is, that there would be a much better way to do it

#get from one data source
for my $movie($review_details1->findnodes('/result_set/results/review')){
    my $id = $movie->findvalue('@movie_id');

    #check if it exists in the other data source
    for my $new_movie($review_details2->findnodes('result_set/results/review')){
        my $new_id = $new_movie->findvalue('@movie_id');
        if ($id eq $new_id){
        print "ID $id matches NEW ID $new_id\n";
        }
    }
}

Cheers

Answer 1

my %ids1;
my %ids2;

# count all the IDs in Details1
$ids1{$_->value}++ foreach @{$review_details1->findnodes('book_reviewers/results/reviewer/@movie_id')};

# count all the IDs in Details2
$ids2{$_->value}++ foreach @{$review_details2->findnodes('book_reviewers/results/reviewer/@movie_id')};

# pass through all keys from IDs2 that also exist in IDs1
grep{exists $ids1{$_}} keys %ids2;

that grep statement will return the list of id's; for you to do with whatever you like, print it, assign it to an array - all yours.