Swift: Get value from a JSON - swift

Question

I'm totally new with swift, it's my first iOs app
I would like to retrieve a value from an http POST response
struct represCode: Codable{
var CODE: String?
}
var table = [represCode]()
func httpPost(completion: #escaping (_ json: Any?)->()) {
let json: [String: Any] = ["login": usernameText.text!.uppercased(),
"pass": mdpText.text!]
let urlPath = url.chaine + "login.php"
let jsonData = try? JSONSerialization.data(withJSONObject: json)
let url = URL(string: urlPath)!
var request = URLRequest(url: url)
request.httpMethod = "POST"
// insert json data to the request
request.httpBody = jsonData
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print(error?.localizedDescription ?? "No data")
return
}
do {
self.table = try JSONDecoder().decode([represCode].self, from: data)
print(self.table)
self.dl = true
}catch _ {
print ("JSON Error")
}
completion(json)
}
task.resume()
}
When I "print(self.table)" I get this
[Mobois.LoginViewController.represCode(CODE: Optional("AG"))]
And I would like to store the "AG" in a specific var (ex: var represCode: String?)
I tried many solutions that I found here but most of time I get errors like "Cannot assign value of type '[LoginViewController.represCode]' to type 'String'"

Answer 1

There are two serious mistakes.
The root object is an array (represented by the [] in [represCode].self)
The value AG is the value for key CODE
First of all to conform to the naming convention declare the struct this way
struct RepresCode: Decodable {
let code: String
private enum CodingKeys: String, CodingKey { case code = "CODE" }
}
and
var table = [RepresCode]()
..
JSONDecoder().decode([RepresCode].self ...
You can access the value by getting the value for property code of the first item in the array
let represCode = table.first?.code ?? "unknown code"