<?php

$json_data = '{
  "basic": {
    "disclosureId": "3390fbd8c33945bef49b7f14e7892e7e3b060c48",
    "disclosureIndex": 1128909,
    "disclosureClass": "ODA",
    "disclosureType": "CA",
    "disclosureCategory": "STT",
    "title": "denenenenenenen",
    "publishDate": "Bugün 21:36",
    "companyId": "74637b1153785250735d48ec3c379a6b8f455fec",
    "companyName": "fgdfgfdgdfgdfhn vfdbfdvsfvsdvsd.",
    "stockCodes": "AADDRR",
    "summary": "SDFSDHGBXFFBXFVDVXDVDXDVXVDCXC CXV",
    "relatedStocks": "",
    "attachmentCount": 7,
    "hasMultiLanguageSupport": true,
    "period": "-",
    "isLate": false,
    "isBlocked": false
  }
}';
$data = json_decode($json_data, true);
$stock_codes = $data['basic']['stockCodes'];
echo $stock_codes

?>