Parsing strange JSON - swift - ios

Question

I am starting my adventure with Swift and iOS developing. And I am fighting for few hours with parsing this json result:
[
[
{
"id": 289462,
"value": "24.80",
"taken_at": "2017-07-02 19:03:03",
"key": "temperature"
}
],
[
{
"id": 289463,
"value": "52.20",
"taken_at": "2017-07-02 19:03:05",
"key": "humidity"
}
]
]
It hasn't got this "name" before all of results, and I don't know, maybe this is causing errors? And below is my function to get data:
func get_data()
{
let headers = [
"content-type": "application/x-www-form-urlencoded",
"cache-control": "no-cache",
"postman-token": "fd20c3c4-650e-743c-3066-597de91f3873"
]
let postData = NSMutableData(data: "auth_key=32fd26f62677e7aa56027d9c228e1e9d6d96abc5d10f547dcb66e2a2f6ed13".data(using: String.Encoding.utf8)!)
let request = NSMutableURLRequest(url: NSURL(string: "http://192.168.0.22/last")! as URL,
cachePolicy: .useProtocolCachePolicy,
timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data
let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
if (error != nil) {
// print(error)
} else {
//let httpResponse = response as? HTTPURLResponse
var keys = [String]()
do {
if let data = data,
let json = try JSONSerialization.jsonObject(with: data) as? [String: Any],
let mes = json[""] as? [[String: Any]] {
for me in mes {
if let name = me["key"] as? String {
keys.append(name)
}
}
}
} catch {
print("Error deserializing JSON: \(error)")
}
print(keys)
}
})
dataTask.resume()
}
I've tried several codes from different sites which I googled and still array is remaining empty :(

Answer 1

You're right the JSON is strange, the root object is [[Any]]. You can get the key values with
if let json = try JSONSerialization.jsonObject(with: data) as? [[Any]] {
for item in json {
if let firstItem = item.first as? [String:Any], let key = firstItem["key"] as? String {
keys.append(key)
}
}
}
However if the JSON was in much more suitable format
[
{
"id": 289462,
"value": "24.80",
"taken_at": "2017-07-02 19:03:03",
"key": "temperature"
},
{
"id": 289463,
"value": "52.20",
"taken_at": "2017-07-02 19:03:05",
"key": "humidity"
}
]
you could reduce the code to
if let json = try JSONSerialization.jsonObject(with: data) as? [[String:Any]] {
keys = json.flatMap { $0["key"] as? String }
}