Re: How to pass two lists to a sub?

use strict;
use warnings;
use Data::Dumper;

my @list1 = qw(a b c);
my @list2 = qw(d e f);

printem([@list1], [@list2]);

sub printem {
  my $list1 = shift or die "no list1";
  my $list2 = shift or die "no list2";
  print "list1: " . Dumper($list1);
  print "list2: " . Dumper($list2);
}
[download]

Comment on Re: How to pass two lists to a sub? Download Code

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Re^2: How to pass two lists to a sub? by wazoox (Prior) on Oct 18, 2006 at 11:26 UTC
Please notice that `printem([@list1], [@list2]);` [download] actually creates two anonymous arrays and copy data in memory, while `printem(\@list1, \@list2)` [download] will pass references to the original arrays. Copying data will prevent accidental changes of the original arrays but may be quite long and memory-hungry if the copied data is big... Here's a small sample to picture the difference : #!/usr/bin/perl use strict; use warnings; use Data::Dumper; my @list1 = qw(a b c); my @list2 = qw(d e f); sub sem { my $list1 = shift or die "no list1"; my $list2 = shift or die "no list2"; $list1->[0]='x'; @{$list2}=qw(D E F); } # print original data print "list1: " . Dumper(@list1); print "list2: " . Dumper(@list2); # call with copy sem([@list1], [@list2]); print "list1: " . Dumper(@list1); print "list2: " . Dumper(@list2); # call by reference sem(\@list1, \@list2); print "list1: " . Dumper(@list1); print "list2: " . Dumper(@list2); [download]	[reply] [d/l] [select]
Re^3: How to pass two lists to a sub? by sanjay nayak (Sexton) on Oct 18, 2006 at 13:36 UTC
Hi Thanks a lot for your suggestion. Regd's Sanjay	[reply]