#!/usr/bin/env perl -l

use strict;
use warnings;

print '*** Create @x with no elements ***';
my @x;
print 'Elements in @x: ', scalar @x;

print '*** Use array index beyond end as RHS of assignment ***';
my $y = $x[42];
print 'Value assigned from beyond end of @x: ', defined $y ? $y : '<undef>';
print 'Elements in @x: ', scalar @x;

print '*** Use array index beyond end as LHS of assignment ***';
$x[21] = 'hello';
for my $i (0, 10, 21, 32) {
    print "Index: $i";
    print 'Value: ', defined $x[$i] ? $x[$i] : '<undef>';
}
print 'Elements in @x: ', scalar @x;

##</code><code>##

*** Create @x with no elements ***
Elements in @x: 0
*** Use array index beyond end as RHS of assignment ***
Value assigned from beyond end of @x: <undef>
Elements in @x: 0
*** Use array index beyond end as LHS of assignment ***
Index: 0
Value: <undef>
Index: 10
Value: <undef>
Index: 21
Value: hello
Index: 32
Value: <undef>
Elements in @x: 22

##</code><code>##

@hash{'goodbye', 'world'} = ();

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;

use Data::Dumper;

my %hash = ('hello', 1, 'goodbye', 2, 'world', 3, 'mars', 4);
print Dumper \%hash;

$hash{goodbye} = ()[0];
$hash{world} = ()[1];
print Dumper \%hash;

##</code><code>##

$VAR1 = {
          'hello' => 1,
          'goodbye' => 2,
          'world' => 3,
          'mars' => 4
        };
$VAR1 = {
          'hello' => 1,
          'goodbye' => undef,
          'world' => undef,
          'mars' => 4
        };

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;

use Data::Dumper;

my %hash = ('hello', 1, 'goodbye', 2, 'world', 3, 'mars', 4);
print Dumper \%hash;

@hash{'goodbye', 'world'} = ('farewell');
print Dumper \%hash;

##</code><code>##

$VAR1 = {
          'hello' => 1,
          'goodbye' => 2,
          'world' => 3,
          'mars' => 4
        };
$VAR1 = {
          'hello' => 1,
          'goodbye' => 'farewell',
          'world' => undef,
          'mars' => 4
        };