use strict;
use warnings;

my $chapters = [
    {
        title   => 'Basic',
        page    => [
            { paragraph => 'lesson1'},
            { paragraph => 'lesson2'},
        ],
    },
    {
        title   => 'Advanced',
        page    => [
            { paragraph => 'lesson3'},
            { paragraph => 'lesson4'},
        ],
    },
];

### since we started with a scalar to hold
    ### an anonymous array ref, we have to
    ### use the little 'arrow' notation

print   $chapters->[0]{title};  ### basic
print   "\n---------------\n";

print   $chapters->[1]{title};  ### advanced
print   "\n---------------\n";

print   $chapters->[1]{page}[0]{paragraph}; ### lesson3
print   "\n---------------\n";

print   $chapters->[1]{page}[1]{paragraph}; ### lesson4
print   "\n---------------\n";