Hello amaa11,

It's difficult to give advice because the code you need to write will be highly dependent on the data structure returned by decode_json, which is highly dependent on the structure of your JSON string.

If you are going to be extracting data from complex JSON strings, then it may be helpful to use a module that helps you extract the data (without having to worry about the perl data structure). One such module is JSON::Path. It lets your write a JSONPath string to extract the data. This way you can write a JSONPath string that will extract only the portion of data that you are interested in and it will reduce the amount of perl code you need to write. I have converted your script of use JSON::Path to give you an example to work from.

#!/usr/bin/env perl
use strict;
use warnings;

use JSON::Path;
 
my $json = '{
  "_embded" : {
    "stes" : [ {
      "SampleSize" : "3,117 ",
      "ge" : false,
      "gx" : false,
      "Count" : 1922309,
      "qualifier" : null,
      "imputed" : true,
      "pooled" : false,
      "Comment" : null,
      "Id" : "G00854",
      "full" : false,
      "Requested" : false,
      "forms" : [ {
        "manufacturer" : "ymetrix"
      } ],
      "ries" : [ {
        "te" : "initial",
        "Individuals" : 4390,
        "Groups" : [ {
          "Group" : "European"
        } ],
        "Origin" : [ ],
        "Recruitment" : [ {
          "majorArea" : "Europe",
          "region" : "Northern Europe",
          "countryName" : "U.K."
        } ]
      }, {
        "te" : "epion",
        "Individuals" : 2698,
        "Groups" : [ {
          "Group" : "European"
        } ],
        "country" : [ ],
        "Recruitment" : [ {
          "majorArea" : "Europe",
          "region" : "Western Europe",
          "countryName" : "Germany"
        } ]
      }, {
        "te" : "ation",
        "Individuals" : 1649,
        "Groups" : [ {
          "Group" : "NR"
        } ],
        "country" : [ ],
        "Recruitment" : [ ]
      } ],
      "sea" : {
        "trt" : "risk"
      },
      "Technologies" : [ {
        "Technology" : "GW"
      } ],
      "SampleSize" : "2,698 ",
      "publicationInfo" : {
        "Id" : "247",
        "publicationDate" : "2016-12-01",
        "publication" : "Psychiat",
        "title" : "GTW.",
        "author" : {
          "fullname" : "Perlis RH",
          "orcid" : null
        },
        "_links" : {
          "stes" : {
            "href" : " ",
            "teated" : true
          }
        }
      },
      "_links" : {
        "self" : {
          "href" : ""
        },
        "sd" : {
          "href" : "",
          "templated" : true
        },
        "asmary" : {
          "href" : ""
        },
        "ets" : {
          "href" : ""
        },
        "ss" : {
          "href" : ""
        },
        "aons" : {
          "href" : ""
        }
      }
    } ]
  },
  "_links" : {
    "self" : {
      "href" : ""
    }
  }
}';
 
my $jpath_stes = JSON::Path->new('$._embded.stes[*]');
# @vals will contain all of the elements of 'stes'
my @vals = $jpath_stes->values($json);

my $jpath_ge = JSON::Path->new('$._embded.stes[0].SampleSize');
# $val will contain the value found for 'SampleSize' in the first elem
+ent of
# the stes array
my $val = $jpath_ge->value($json);
print "SampleSize: $val\n";

exit;

[download]
If you choose to use this module, I recommend you carefully read the documentation for the JSON::Path and JSONPath - XPath for JSON.

In reply to Re^6: parse json data with underscore symbol by kevbot
in thread parse json data with underscore symbol by amaa11

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