#!/usr/bin/perl

#use strict;
use warnings;

sub foo { $n++; }

$n = 10;

print "$n\n";  # 10
foo();
print "$n\n";  # 11

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

sub foo { $n++; }   # Compile-time (strict) error!

our $n = 10;

print "$n\n";  # 10
foo();
print "$n\n";  # 11

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

# "our $n;" disables "use strict 'vars';" for $n for the
# remainder of the lexical scope in which it is located.

sub foo { our $n; $n++; }

our $n = 10;

print "$n\n";  # 10
foo();
print "$n\n";  # 11

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

sub foo { my $n; $n++; }   # Different $n!

my $n = 10;

print "$n\n";  # 10
foo();
print "$n\n";  # 10

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

sub foo { $n++; }   # Compile-time (strict) error!

my $n = 10;

print "$n\n";
foo();
print "$n\n";

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

my $n = 10;

sub foo { $n++; }

print "$n\n";  # 10
foo();
print "$n\n";  # 11