Parse Json with a definition at the beginning - json

Question

I want to parse a Json file with this structure:
{"x":"exchange","b":"usd","ds":["exchange","avgp","mcap","ppc7D","ppc12h","ppc4h","ppc24h"],"data":[["Dow Jones","16360.447","273.89B","6.62","2.14","-0.59","-1.99"],["Dax","877.422","6.80B","38.15","-7.4","-4.44","-4.12"],["nikkei","30.077","2.96B","24.22","-2.3","-4.02","-4.95"],["ATX","281.509","15.29B","214.97","-5.48","-4.58","-10.77"]]}
I do not know how to parse a Json file where there is no definition like:
exchange = "Dow Jones", avgp = 16360.477" etc.
And i could not found anything online.
My code looks like this:
let json = """
{"x":"exchange","b":"usd","ds":["exchange","avgp","mcap","ppc7D","ppc12h","ppc4h","ppc24h"],"data":[["Dow Jones","16360.447","273.89B","6.62","2.14","-0.59","-1.99"],["Dax","877.422","6.80B","38.15","-7.4","-4.44","-4.12"],["nikkei","30.077","2.96B","24.22","-2.3","-4.02","-4.95"],["ATX","281.509","15.29B","214.97","-5.48","-4.58","-10.77"]]}
""".data(using: .utf8)!
struct JsonWebsocket: Decodable {
let exchange: String
let avgp: String
let mcap: String
let ppc7D: String
let ppc12h: String
let ppc4h: String
let ppc24h: String
init(exchange: String, avgp: String, mcap: String, ppc7D: String, ppc12h: String, ppc4h: String, ppc24h: String) {
self.exchange = exchange
self.avgp = avgp
self.mcap = mcap
self.ppc7D = ppc7D
self.ppc12h = ppc24h
self.ppc4h = ppc4h
self.ppc24h = ppc24h
}
}
func fetchJson() -> [String:JsonWebsocket] {
let jsonCoinsDecode = json
let coinDecode = JSONDecoder()
let output = try! coinDecode.decode([String:JsonWebsocket].self, from: jsonCoinsDecode)
return output
}
let array = fetchDataTradingPairs()
But of course it returns an error as the structure does not match the json file.
Does anyone know how to parse this json?
Thanks!

Answer 1

create a struct like that.
struct JsonWebsocket: Decodable {
let x: String
let b: String
let ds: [String]
let data: [[String]]
}
and decode
do {
let coinDecode = JSONDecoder()
let output = try coinDecode.decode(JsonWebsocket.self, from: json)
print(output.data)
}
catch let error{
print(error.localizedDescription)
}
alter native
otherwise, create a custom
struct JsonWebsocket: Decodable {
let exchange: String
let avgp: String
let mcap: String
let ppc7D: String
let ppc12h: String
let ppc4h: String
let ppc24h: String
init(json: [String]) {
self.exchange = json[0]
self.avgp = json[1]
self.mcap = json[2]
self.ppc7D = json[3]
self.ppc12h = json[4]
self.ppc4h = json[5]
self.ppc24h = json[6]
}
}
do {
let jsonData = try JSONSerialization.jsonObject(with: json, options: []) as? [String: Any]
var jsonWebsocket: [JsonWebsocket] = []
if let data = jsonData!["data"] as? [[String]] {
for d in data {
jsonWebsocket.append(JsonWebsocket(json: d))
}
}
print(jsonWebsocket.count)
}
catch let error{
print(error.localizedDescription)
}