ModernPerlQuestion

#!/usr/bin/env perl
use v5.12;
#use Test::More;
#use Modern::Perl;
use Modern::Perl 2011;
use autodie;
use Data::Dumper;

## Example from here:
# http://modernperlbooks.com/books/modern_perl_2014/03-perl-language.html#TmVzdGVkRGF0YVN0cnVjdHVyZXM
## Perl Version
# $ perl -v
# This is perl 5, version 12, subversion 4 (v5.12.4) built for darwin-thread-multi-2level
# (with 2 registered patches, see perl -V for more detail)


    ## Code snippet below did not work, got undefined values.
    ## Had to first declare 'entree' with my in one statement, then assign to it.
    ## Question: Wondering why this has to be so, and why the book version does not work, as
    ## it seems that it should.
my %meals = (
    breakfast => { entree => 'eggs',
                   side   => 'hash browns' },
    lunch     => { entree => 'panini',
                   side   => 'apple'},
    dinner    => { entree => 'steak',
                    side   => 'avocado salad' },
);


## Work on structure


    ## From the book:
my ($entree, $side) = @{ $_ }{qw(entree side)} for $meals{breakfast};
defined $entree ? say "book version entree defined." : say "book version entree NOT defined.";
## Output:
#book version entree NOT defined.


    ## How I made work
my ($entree2, $side2);
($entree2, $side2) = @{ $_ }{qw(entree side)} for $meals{breakfast};
defined $entree2 ? say "predeclare entree2 defined." : say "predelcare entree2 NOT defined.";
## Output:
#predeclare entree2 defined.