my $n;
for (1..10000000) 
{
    $n = $_**2;
}

versus:

my $n;
for (1..10000000) 
{
    state $n = $_**2;
}

##</code><code>##

#!/usr/bin/perl -w
use strict;
use 5.10.0;

foreach (1..5)
{
   print nextNum(),"\n";
}

sub nextNum
{
   state $num =10;
   return $num++;
}

__END__
Prints:
10
11
12
13
14