JSON from array prints invalid json

Question

I have a script I have been using where a user will enter a search string and it will then return the json result of the search. I however had to make changes and let the script search for the data in a table and print a json result. I created a for loop to use perform this task. (posted a sample of the for loop which is the only relevant part here):

#!/bin/perl
use strict;
use warnings;
use JSON;
$json = JSON->new->allow_nonref;
...
foreach (...) {
      my $object = {name => "$name", surname => "$surname", age => "$age"}, 'response';
      my $result = $json->encode($object);
      print "$result";
  }

This does exactly what it use to and prints the each element in valid json format (manually made it pretty):

{
   "name" : "Sarah",
   "surname" : "O'Conner",
   "age" : "89"
}
{
   "name" : "John",
   "surname" : "Smith",
   "age" : "32"
}

The problem is that each each json elements are valid, but invalid as multiple root elements. I instead needed this:

[
   {
      "name":"Sarah",
      "surname":"O'Conner",
      "age":"89"
   },
   {
      "name":"John",
      "surname":"Smith",
      "age":"32"
   }
]

I tried 20 different ways but I just cannot fix this. Can anyone please help me with fixing this? How do I get the result as a multiple root element and separate elements?

Answer 1

Create an array of the "objects" (called hashes in Perl) and encode it:

my @objects;
foreach (...) {
      push @objects, {name => $name, surname => $surname, age => $age};
}
my $result = $json->encode(\@objects);
print $result;

If you show us the ... part, we might show you how to translate it to @objects directly without pushing (e.g. using a map).

BTW, there's no need to doublequote variables.

Answer 2

You're doing the JSON conversion at the wrong point of the process. Instead of converting each individual record, you should create an array of your records and convert that.

#!/bin/perl
use strict;
use warnings;
use JSON;
$json = JSON->new->allow_nonref;
...
my @objects;

foreach (...) {
      my $object = {name => "$name", surname => "$surname", age => "$age"};
      push @objects, $object;
}

my $result = $json->encode(\@objects);
print "$result";