Get element of array not looping.

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks,

Whats the way to manually access the firt element of this arrays without looping?

Test Code:

#!/usr/bin/env perl

use strict;
use warnings;


my $DATA = {

            "facts": [
                {
                    "name": "A", 
                    "type": "Normal"
                }, 
                {
                    "name": "B", 
                    "type": "Broken"
                }
            ],

 };

 print $DATA->{ facts }->{ name }->[0]; # A
 print $DATA->{ facts }->{ type }->[0]; # Normal
 exit;
[download]

Thanks for looking!

Comment on Get element of array not looping. Download Code

Replies are listed 'Best First'.
Re: Get element of array not looping. by choroba (Cardinal) on Jul 13, 2021 at 17:59 UTC
`syntax error at ./script.pl line 8, near ""facts":"` [download] Perl can parse JSON, but only from a string, not directly from the source code. In Perl hashes, keys are separated by commas or fat commas from the values, not colons. Then, you can do: `my $DATA = { facts => [ { name => 'A', type => 'Normal' }, { name => 'B', type => 'Broken' } ], }; print $DATA->{facts}[0]{name}; # A print $DATA->{facts}[0]{type}; # Normal` [download] It's a hash containing an array containing hashes, not a hash of hashes of arrays. Or, parse the JSON, but remove the trailing comma after the array, JSON doesn't support it: `#!/usr/bin/perl use warnings; use strict; use Cpanel::JSON::XS; my $DATA = decode_json('{ "facts": [ { "name": "A", "type": "Normal" }, { "name": "B", "type": "Broken" } ] }'); print $DATA->{facts}[0]{name}; # A print $DATA->{facts}[0]{type}; # Normal` [download] `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]
Re^2: Get element of array not looping. by Anonymous Monk on Jul 13, 2021 at 18:58 UTC
Perfect, thank you!!!	[reply]
Re: Get element of array not looping. by AnomalousMonk (Archbishop) on Jul 13, 2021 at 22:40 UTC
More info on working with complex Perl data structures (once you get them into the right syntax :) is found in the Perl Data Structures Cookbook (perldsc). Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]