CASE1:
my @result = map $_*2, @list;

##</code><code>##

@result = join (',',@result);

##</code><code>##

CASE2:
my @result = map $_*55, @list;

##</code><code>##

@result = join (',',@result);

##</code><code>##

#!/usr/local/bin/perl
use strict;
use warnings;
use Devel::Size qw(size total_size);

my @list = qw(1 2 3 4);
my @result = map $_*55, @list;

@list = join(',',@list);
#@result = join (',',@result);

print qq(the size of "@list" is: ).total_size(\@list). " Bytes\n";
print qq(the size of "@result" is: ).total_size(\@result)." Bytes\n";