understanding json in perl- encoding and decoding. Why?

[bio_informatics]

Hello members,
I am new to json. I know it is key value pair, and that is it.
I am using language-Perl.

What is encode, decode in it? Why do we require?

use strict;
use autodie;
use Data::Dumper;
use IO::File;
use warnings;
use JSON::PP;
my %rec_hash = ('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5);
my $json = encode_json \%rec_hash;
print "$json\n";

my $son = '{
        "trans1": [20,30]
}';


print $son;

my output is:

{"e":5,"c":3,"a":1,"b":2,"d":4}
{
"trans1": [20,30]
}

Questions:
1- when should I use hash for initiating json?
2- I want to print output as

{
"trans1": [20,30]
}
This is the output I want in a new file. So is it a encoded one or decoded one? I will read this output from a python a script.

Also, there is tonnes of info on utf-8 for Json, I couldn't get much on that.

Please guide me here.

[par]

JSON encoding will take a data structure (in Perl, Python, etc) and encode it as a string in a standard format. decode turns the string back into the data structure. You can encode literals (numbers, strings), arrays, and hashes.

Whether you encode a hash or an array depends on the data you need to encode. In your example, you want to encode a hash to produce a JSON string that's wrapped in the "{ }" and has key-value pairs.