$v += $v;
print "$v\n";

##</code><code>##

my $x = 'A';
++$x;
print "$x\n";

##</code><code>##

use warnings;
use strict;
my $v = 99;
$v = sprintf( "%04d", $v );
print "$v\n";
$v += 1;
print "$v\n";

$v += $v;
print "$v\n";

##</code><code>##

0099
100
200