I'm trying to parse out a the [confirmation_code] value in the following json data.  Is there a way I can quickly do this using a feature in Oracle 12c?
stdClass Object
(
    [1] => stdClass Object
        (
            [1] => Array
                (
                )
        )
    [2] => stdClass Object
        (
            [1] => stdClass Object
                (
                    [submission_site] => 1
                    [submission_code] => 111111
                )
        )
    [3] => stdClass Object
        (
            [1] => {"name":"file.xml","type":"text\/xml","tmp_name":"\/tmp\/phpKkAxJI","error":0,"size":715,"mime_type":"application\/xml","virus_scan_success":true,"virus_scan_message":"Virus scan success.","error_message":"[{\"priority\":1,\"message\":\"Saved successfully\"}]","clob_id":"99999"}
        )
    [4] => stdClass Object
        (
            [1] => stdClass Object
                (
                    [confirmation_code] => JDY7RC
                )
        )
) 
 
That doesn't look too much like JSON to me ? besides the inner bit "{name: ... etc}".  Looks more like PHP.
Anyway...you can parse out pieces of information from JSON in 12c using a variety of means.
Here's an example using JSON_TABLE taken from the JSON team's blog 
https://blogs.oracle.com/jsondb SQL> CREATE TABLE fb_tab (col CLOB, constraint json_con_1 CHECK (col IS JSON));
Table created.
SQL>
SQL> INSERT INTO fb_tab VALUES('
  2   {
  3    "data": [
  4     {
  5      "from": {
  6      "category": "Computers/technology",
  7      "name": "Oracle",
  8     },
  9     "message": "How are Baxters Food Group and Elsevier taking their businesses",
 10     "link": "http://onforb.es/1JOki7X",
 11     "name": "Forbes: How The Cloud Answers Two Businesses'' Need For Speed",
 12     "description": "Cloud computing can support a company''s speed and agility, ...",
 13     "type": "link",
 14     "created_time": "2015-05-12T16:26:12+0000",
 15     "likes": {
 16      "data": [
 17       {
 18         "name": "Starup Haji"
 19       },
 20       {
 21         "name": "Elaine Dala"
 22       }
 23      ]
 24     }
 25    },
 26    {
 27     "from": {
 28      "category": "Computers/technology",
 29      "name": "Oracle",
 30     },
 31     "message": "It''s important to have an IT approach that not only red...",
 32     "link": "http://www.forbes.com/sites/oracle/2015/05/07/3-ways-you-can-avoid-sp...",
 33     "name": "Forbes: 3 Ways You Can Avoid Spending Too Much On IT",
 34     "description": "Oracle''s suite of SaaS applications not only reduces costs but...",
 35     "type": "link",
 36     "created_time": "2015-05-11T19:23:11+0000",
 37     "shares": {
 38     "count": 5
 39    },
 40    "likes": {
 41    "data": [
 42     {
 43      "name": "Asal Alibiga"
 44     },
 45     {
 46      "name": "Hasan Reni"
 47     }
 48    ]
 49   },
 50   "comments": {
 51     "data": [
 52       {
 53         "from": {
 54           "name": "Cesar Sanchez"
 55         },
 56         "message": "Thanks for this information",
 57         "created_time": "2015-05-12T02:52:09+0000",
 58         "like_count": 1
 59       }
 60      ]
 61     }
 62    }
 63   ]
 64  }
 65  ');
1 row created.
SQL>
SQL> SELECT jt.*
  2  FROM fb_tab,
  3       JSON_TABLE(col, '$.data[*]'
  4        COLUMNS (
  5         "Message" PATH '$.message',
  6         "Type"  VARCHAR2(20)PATH '$.type',
  7         "ShareCount"  NUMBER  PATH '$.shares.count' DEFAULT 0 ON ERROR,
  8         "HasComments"  NUMBER EXISTS  PATH '$.comments',
  9         "Comments"  VARCHAR2(4000) FORMAT JSON PATH '$.comments'
 10      )) "JT";
MESSAGE
----------------------------------------------------------------------------------------------------------------------------------
TYPE                 SHARECOUNT HASCOMMENTS
-------------------- ---------- -----------
COMMENTS
----------------------------------------------------------------------------------------------------------------------------------
How are Baxters Food Group and Elsevier taking their businesses
link                                      0
It's important to have an IT approach that not only red...
link                          5           1
{"data":[{"from":{"name":"Cesar Sanchez"},"message":"Thanks for this information","created_time":"2015-05-12T02:52:09+0000","like_
count":1}]}
SQL> col message format a40 trunc
SQL> col comments format a40 trunc
SQL> set lines 200
SQL> /
MESSAGE                                  TYPE                 SHARECOUNT HASCOMMENTS COMMENTS
---------------------------------------- -------------------- ---------- ----------- ----------------------------------------
How are Baxters Food Group and Elsevier  link                                      0
It's important to have an IT approach th link                          5           1 {"data":[{"from":{"name":"Cesar Sanchez"
Some simpler examples can also be found on Tim Hall's site 
https://oracle-base.com/articles/12c/json-support-in-oracle-database-12cr1