Ambiguous error message from JSON::Path

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

Hey monks,

I have trouble to get the following code to run:

use JSON::Path;
$json = q( { "array": [ 1, 2, 3], "string": "string_value", "object": 
+{ "obj1": "val1", "obj2": "val2" } } );
$arr_path = JSON::Path->new( q($.array) );
$scal_path = JSON::Path->new( q($.string) );
$value = $arr_path->value();

if ( ! ( defined ref $value ) )

{ print "SCALAR\n" }

elsif ( ref $value eq q(ARRAY) ) { print "ARRAY\n" }

else { print "NEITHER" }
[download]

I get the following error message:

Use of uninitialized value $json_object in concatenation (.) or string
+ at /usr/local/share/perl/5.20.2/JSON/Path/Evaluator.pm line 84.
Unable to decode  as JSON: malformed JSON string, neither tag, array, 
+object, number, string or atom, at character offset 0 (before "(end o
+f string)") at /usr/local/share/perl/5.20.2/JSON/Path/Evaluator.pm li
+ne 81.
 at /usr/local/share/perl/5.20.2/JSON/Path/Evaluator.pm line 79.
[download]

According to JSONLint $json is valid JSON. Therefore I do not understand the error message.

What's goin' wrong?

Comment on Ambiguous error message from JSON::Path Select or Download Code

Replies are listed 'Best First'.
Re: Ambiguous error message from JSON::Path by choroba (Cardinal) on Apr 16, 2018 at 07:31 UTC
Where do you pass $json to JSON::Path? The documentation seems to pass the json string to the value method. ($q=q:Sq=~/;[c](.)(.)/;chr(-\|\|-\|5+lengthSq)`"S\|oS2"`map{chr \|+ord }map{substrSq`S_+\|`\|}3E\|-\|`7**2-3:)=~y+S\|`+$1,++print+eval$q,q,a, [download]	[reply] [d/l]
Re: Ambiguous error message from JSON::Path by Discipulus (Canon) on Apr 16, 2018 at 07:36 UTC
Hello, it seems you need `my $value = $arr_path->value( $json );` instead of `$value = $arr_path->value();` I also added `use strict` and `use warnings` .. L* There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l] [select]