Debugging (pretty printing)

• Data::Dumper

But once we have those references we have a better tool to print out their content.

#!/usr/bin/env perl
use strict;
use warnings;

use Data::Dumper qw(Dumper);

my @names     = qw(Foo Bar Baz);
my $names_ref = \@names;

my %phones = (
    Foo  => 123,
    Bar  => 456,
    Baz  => 789,
);
my $phones_ref = \%phones;

print Dumper $names_ref, $phones_ref;

$VAR1 = [
          'Foo',
          'Bar',
          'Baz'
        ];
$VAR2 = {
          'Bar' => 456,
          'Baz' => 789,
          'Foo' => 123
        };

Actually you can use the Dumper on the references themself without putting them in scalar variables.

print Dumper \@names, \%phones;