Perl: making an array ref out of a scalar variable inside of a hash

Question

Can anybody please let me know how can I make an array ref out of a scalar variable (equivalent to a hash ref)? The code I have so far is:

#! /usr/bin/perl
use strict;

my $index=0;
my $car={};

$car->{model}[$index]="Tesla";
my $texxt = $car->{model}[$index];
@{$texxt}=qw(1 2 3);

print "@{$texxt}";

This gives the following error: Can't use string ("Tesla") as an ARRAY ref while "strict refs" in use at test99.pl line 8.

Basically I am trying to make an array (or an array ref) called "@Tesla" that has values (1 2 3).

Thanks for your help!

I'm having a bit of trouble figuring out what kind of datastructure you want to have in the end. Hash of arrays? Hash of hashes? Can you elaborate? c.f. perldsc. — G. Cito
– G. Cito, Commented Nov 1, 2014 at 5:24

G. Cito · Accepted Answer · 2014-11-01 05:30:43Z

1

If you want a hash with a key called "model" that contains an array with "Tesla" as the first element and an anonymous array as the second element (and texxt as a short cut reference to that) then this would work

#! /usr/bin/perl
use strict;

my $index=0;
my $car={};

$car->{model}[$index]="Tesla";
my $texxt = $car->{model} ;
push @{$texxt} , [qw(1 2 3)];

print ref eq "ARRAY" ? "@{$_}" : "$_ " for @{$texxt} ;

output: Tesla 1 2 3

You can use Data::Printer to view the data structure in a nicely formatted way:

use DDP;
p $texxt;

outputs:

\ [
    [0] "Tesla",
    [1] [
        [0] 1,
        [1] 2,
        [2] 3
    ]
]

This can help you visualize what perl is doing to your data.

edited Nov 1, 2014 at 5:30

answered Nov 1, 2014 at 5:21

G. Cito

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Comments

choroba · Accepted Answer · 2014-11-01 00:43:20Z

0

If $texxt is a string (it's not a hash ref), you cannot dereference it as an array. You can assign an anonymous array to it, though:

$texxt = 'Tesla';
$texxt = [qw[ 1 2 3 ]];

answered Nov 1, 2014 at 0:43

choroba

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