The same as the last time you asked, and the time before that :P

#!/usr/bin/perl
use strict;
use warnings;
use Mojo::UserAgent;
use feature 'say';

my $url_food  = 'https://api.nal.usda.gov/fdc/v1/food/170581?api_key=O
+c4bD3tFWgPAscW0R0gBRivwqEdt0N182PXCGNQO';
my $ua_food   = Mojo::UserAgent->new;
my $json_food = $ua_food->get($url_food)->res->json;
say $json_food->{fdcId};

foreach my $nutrients( @{$json_food->{'foodNutrients'}} ){
  say $nutrients->{'nutrient'}{'name'};
}
[download]

You're right (and diligent). Sorry for wasting your time. I was tired and frustrated and not thinking clearly.

It happens to us all, and these are the right circumstances to ask others for help. Don't worry about it :)

Hi,

It's a little confusing but $mojo->tx->res->json returns the de-serialized data from the JSON response.

So for clarity you should rename your $json_food variable to, e.g., $data_food. You can then access elements of the hashref as you would normally, e.g. $data_food->{fdcId}.

Hope this helps!

G'day anautismobserver,

Decode (to a Perl data structure) using JSON. If you also have JSON::XS installed, it will run faster. You can use JSON::XS directly, but some users who maybe can't compile XS code will not be able to run your script. [See Update below]

Once you have the JSON data in a Perl format, getting the wanted values is pretty straightforward. See "perldsc - Perl Data Structures Cookbook" if you don't know how to do this.

Update: I took "Below is code that returns a JSON object." on face value and, in line with the title, "decoding a JSON object", provided a generic response on how to achieve that. I think you can be forgiven for assuming a method called json() returns JSON; however, that's not the case — see ++1nickt's explanation.

Sorry, but the first paragraph is not applicable here - Mojo has JSON decoding already built in, and $json_food will already contain decoded JSON due to the ->json call.