Json data to label - ios

Question

I have been struggling with this for a while and just need some quick help with this basic question.
let url = URL(string: "https://api.coindesk.com/v1/bpi/currentprice.json")
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
if error != nil
{
print ("Error!")
}
else
{
if let content = data
{
do
{
// Array
let myJson = try JSONSerialization.jsonObject(with: content, options: JSONSerialization.ReadingOptions.mutableContainers) as AnyObject
if let rates = myJson["bpi"] as? NSDictionary
{
if let currency = rates["USD"] as NSDictionary
{
if let money = currency["rate"]
{
print(money)
}
}
}
}
catch
{
}
}
}
}
task.resume()
self.label.text = (self.money as String?)
I am trying to pass the numerical value for "money" to a label in my view controller.

Answer 1

The main issue is that you are trying to update the label from outside the completion handler of your asynchronous network request. However, there are several other issues with your code. You shouldn't use NSDictionary in Swift, use [String:Any] when parsing JSON dictionaries. .mutableContainers also doesn't have any effect in Swift. Also make sure that you dispatch any UI related updates to the main thread.
let url = URL(string: "https://api.coindesk.com/v1/bpi/currentprice.json")
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
guard let data = data else {
print(error!); return
}
do {
if let myJson = try JSONSerialization.jsonObject(with: content) as? [String:Any],
let rates = myJson["bpi"] as? [String:Any],
let currency = rates["USD"] as? [String:Any],
let money = currency["rate"] as? String {
DispatchQueue.main.async{
self.label.text = money
}
}
} catch{
print(error)
}
}
task.resume()