[SOLVED]JSONをパースしてキーに入ってる配列を扱う際、期待した動きにならないけど、どうしてだろう？

conv.pl

#!/usr/bin/env perl
use strict;
use warnings;
use utf8;
use feature qw/say/;
use Encode;
use Data::Dumper;
use JSON;
use File::Slurp qw/read_file write_file/;

my $json = JSON::decode_json File::Slurp::read_file 'data.json';

say 'confirm ref() shows type only with reference';
my @array = (1,2,3);
print 'say @array: ';
    say @array;
print 'say ref @array; ';
    say ref @array;
my $ref =\@array;
print 'say $ref; ';
    say $ref;
print 'say ref $ref: ';
    say ref $ref;
say '-----------------------------------';
foreach my $key (keys %$json){
    say sprintf 'In foreach loop. key is now "%s"', $key;
    my $type = ref $json->{$key};
    say sprintf '$json->{$key} is %s', $type;

    say '-----------------------------------';

    say 'foreach my $item (@array)';
    say 'unexpected behavior...';
    my @array = $json->{$key};
    foreach my $item (@array){
        say Dumper $item;
    }

    say '-----------------------------------';

    say 'foreach my $item (@$ref)';
    say 'expected behavir!';
    my $ref = $json->{$key};
    foreach my $item (@$ref){
        say Dumper $item;
    }

    say '-----------------------------------';

    say 'advised solution.';
    say 'that unexpected behavior is because $json->{$key} gives array ref. not array';
    say 'expected behavir!';
    my @array2 = @{$json->{$key}};
    foreach my $item (@array2){
        say Dumper $item;
    }
}

data.json

{
    "foo": [{
        "key": 1
    },{
        "key": 2
    },{
        "key": 3
    }],
    "bar": [{
        "key": 1
    },{
        "key": 2
    },{
        "key": 3
    }]
}