here is my updated code
use strict; use warnings;
Yeah!! :)
while(<IBDIN>){
my @array_a = split ' ', <IBDIN>;
my @array_b = split ' ', <IBDIN>;
compare_array();
}
By declaring the arrays within a while loop, they are not accessible outside the loop. That's why Perl complains. (Suggested reading, since you seem not to be used to strictures: http://perl.plover.com/FAQs/Namespaces.html)
This is what I first suggested:
my @array_a = split ' ', <IBDIN>;
my @array_b = split ' ', <IBDIN>;
compare_array();i.e. no loop at all. If you prefer a while loop, two named arrays is not very suitable. In that case, you may use an array of arrays instead:
my @arrays;
while(<IBDIN>){
@{ $arrays[$.] } = split ' ';
}
compare_array();But if you are not familiar with Perl data structures, why not stick to the option without a while loop.
sub compare_array {
my (%seen, @bonly);
@[EMAIL PROTECTED] = (); # build lookup table
foreach my $item (@array_b){
push(@bonly, $item) unless exists $seen{$item};
}
print "@bonly \n";
}
Since you now are using a subroutine, I'd like to make a comment with respect to style. It's good programming practice to pass variables to a subroutine rather than having it process file scoped variables. With that in mind, I'd suggest the following:
open IBDIN, "<$file" or die "cannot open $file $!";
my @array_a = split ' ', <IBDIN>;
my @array_b = split ' ', <IBDIN>;
close IBDIN;compare_array( [EMAIL PROTECTED], [EMAIL PROTECTED] );
sub compare_array {
my ($ref_a, $ref_b) = @_;
my (%seen, @bonly);
@seen{ @$ref_a } = (); # build lookup table
foreach my $item ( @$ref_b ) {
push (@bonly, $item) unless exists $seen{$item};
}
print "@bonly \n";
}-- Gunnar Hjalmarsson Email: http://www.gunnar.cc/cgi-bin/contact.pl
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