You examples look fine to me too, but if you really want to do it differently, this seems to work too

#!/usr/bin/perl  -l

use strict;
use warnings;

my @arr = ( 1,2,3,4,5) ;
my $n = 1 ;
my @new = map{ $n = 1000; ++$_ } @arr ;

print "new=@new";
print "n=$n\n";
[download]

Cheers
LuCa