#!/usr/bin/env perl -l

use strict;
use warnings;

my $host = 'localhost';

BEGIN {
    print 'Host: ', $host;
}

##</code><code>##

$ pm_1125079_begin_before_use.pl
Use of uninitialized value $host in print at ./pm_1125079_begin_before_use.pl line 9.
Host: 

##</code><code>##

#!/usr/bin/env perl -l

use strict;
use warnings;

my $host;
BEGIN {
    $host = 'localhost';
}
BEGIN {
    print 'Host: ', $host;
}

##</code><code>##

$ pm_1125079_begin_before_use.pl
Host: localhost