Perl JSON decoding and print key from key value pair

Question

I am a Perl newbie and want to loop over JSON data.
This is my code:

use JSON::XS;
my $jsonxx = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
my $text = decode_json($jsonxx);
foreach my $key(keys %$text) {
    print "$key\n";
}

and output is:

e
c
a
b
d

But I want output in the order of key-value pair given.

Expected Output:

a
b
c
d
e

Can anyone please help?

This is not possible. JSON objects/Perl hashes are unordered by definition. You can sort the keys, though, which might still get you what you want. If you need an ordered collection, an array is what you want. — Matt Jacob, Oct 20 '15 at 05:36
for(sort { $h->{$a} <=> $h->{$b} } keys %$h) { print "$_\n" } if you need sorted output. Sorted hash isn't possible — red0ct, Oct 20 '15 at 11:55

score 1 · Answer 1 · answered Oct 20 '15 at 05:42

1

I guess using sort will give you expected output:

foreach my $key(sort keys %$text) {
    print "$key\n";
}

answered Oct 20 '15 at 05:42

serenesat

JSON data may vary. Actually i want output in the order key-value pair added. – Soorajlal K G Oct 20 '15 at 05:57
1

@SoorajlalKG It's an object. An object is an unordered set of name/value pairs. **There is no order.** – Matt Jacob Oct 20 '15 at 06:13
You can output your JSON by setting `canonical`. – Sobrique Oct 20 '15 at 08:42

1 Answers1