$re = '/(?<=\"id\"\:)\d+(?=\,)/m';
$str = '{
"id": 5987431,
"remoteRef": "f150edeab22e5458a8d5db64280023f0",
"paymentEntityType": "Bank",
"accountHolder": "Svilen Varbanov",
"accountNumber": "********6691",
"expiresEnd": null,
"paymentEntityStatus": "Unverified",
"token": null,
"canDeposit": false,
"canWithdraw": false,
"lastUsed": false,
"cardType": null,
"logs": [
{
"paymentEntityStatus": "Unverified",
"message": "Bank payment entity has been created.",
"updated": "2019-10-01 11:49:22Z"
}
],
"transactionSummaries": null,
"paymentGateway": "RBC",
"details": {
"bankName": null,
"sortCode": null,
"swiftCode": null,
"branchCode": null,
"branchAddress": null,
"transitNumber": "340",
"institutionNumber": "34103",
"accountId": "575876691"
},
"createdAt": "2019-10-01T11:49:22.4680708Z"
}';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php