no strict;      # just for this demo
use warnings;

my $ref         = \do{ my $anon = 42 };
my $deref       = ${ $ref };

print '$ref: '          , "$ref\n";	
print '$deref: '        , "$deref\n";	
print '$anon: '         , "$anon\n";	

__END__

Output:

Name "main::anon" used only once: possible typo at ./anon-scalar-ref-demo.pl line 9.
$ref: SCALAR(0x9dbefd8)
$deref: 42
Use of uninitialized value $anon in concatenation (.) or string at ./anon-scalar-ref-demo.pl line 9.
$anon: 


##</code><code>##

my @arr      = (1, 2, 3);
my $ref      = \@arr;