my @var_array = (1,2,3,4,5,6);
my $var, my $r = 0;
my %hash();

foreach my $var_p (@var_array){
  $var = 3+$r;
  
  #hash with $var_p key and $var value:
  #%hash = (
  # 1 => 3,
  # 2 => 4,
  # ...
  # 6 => 8,
  #);

  print "### $var\n";
  $r++;
}