use JSON qw(objToJson); # from the CPAN

 my $data = [
        [ "264","O","3"],
        [ "24","ED","5","Enh"],
        [ "368","B", "fng"] 
           ];
print objToJson($data), "\n";
[download]

[[264,"O",3],[24,"ED",5,"Enh"],[368,"B","fng"]]
[download]

I'll take this chance to booster for JSON:XS too. I dropped it into serialize.pl and got this-

Modules
JSON        : 1.07
JSON::PC    : 0.01
JSON::Syck  : 0.26
JSON::XS    : 1.53
Storable    : 2.15
XML::Simple : 2.14
YAML        : 0.65
YAML::Syck  : 0.99

Deflate
               Rate   YAML XML::Simple JSON YAML::Syck Storable JSON::
+Syck JSON::PC JSON::XS
YAML          107/s     --        -89% -92%       -98%     -98%       
+-98%     -99%     -99%
XML::Simple   990/s   822%          -- -24%       -81%     -81%       
+-81%     -92%     -93%
JSON         1305/s  1115%         32%   --       -75%     -75%       
+-76%     -90%     -90%
YAML::Syck   5207/s  4748%        426% 299%         --      -1%       
+ -2%     -59%     -62%
Storable     5239/s  4778%        429% 301%         1%       --       
+ -2%     -59%     -62%
JSON::Syck   5338/s  4870%        439% 309%         3%       2%       
+  --     -58%     -61%
JSON::PC    12687/s 11712%       1181% 872%       144%     142%       
+138%       --      -7%
JSON::XS    13652/s 12611%       1279% 946%       162%     161%       
+156%       8%       --

Inflate
               Rate   YAML XML::Simple  JSON YAML::Syck JSON::Syck JSO
+N::PC Storable JSON::XS
YAML         82.2/s     --        -62%  -84%       -98%       -98%    
+ -99%    -100%    -100%
XML::Simple   217/s   165%          --  -59%       -94%       -94%    
+ -97%     -99%     -99%
JSON          527/s   542%        143%    --       -85%       -85%    
+ -94%     -97%     -97%
YAML::Syck   3412/s  4052%       1470%  547%         --        -6%    
+ -59%     -82%     -83%
JSON::Syck   3622/s  4307%       1566%  587%         6%         --    
+ -56%     -81%     -81%
JSON::PC     8295/s  9994%       3716% 1473%       143%       129%    
+   --     -56%     -57%
Storable    18980/s 22996%       8631% 3499%       456%       424%    
+ 129%       --      -3%
JSON::XS    19504/s 23634%       8872% 3598%       472%       439%    
+ 135%       3%       --
[download]

I did find reserialization (roundtrip) problems with vanilla JSON.pm when using it for a project recently.

use JSON::Any;
$json = JSON::Any->new()->encode( $yourAofA );
[download]