Return variable specified inside closure - Swift [duplicate] - json

Question

This question already has answers here:
Returning data from async call in Swift function
(13 answers)
Closed 5 years ago.
I am trying to get a string out from an external JSON file, which is on a web server, and it gets it successfully, but it is inside a closure where it gets the value, and I need to get it outside so I can return it with the variable returnip How do I do this?
func getJsonFromUrl() -> String {
let URL2 = "https://url.com/asd.php";
let url = URL(string: URL2)
URLSession.shared.dataTask(with:url!) { (data, response, error) in
if error != nil {
print(error as Any)
} else {
do {
let parsedData = try JSONSerialization.jsonObject(with: data!) as! [String:Any]
let ips = parsedData["ip"] as! String
print("The IP is: " + ips) //Prints the value correctly
var returnip = ips //The value that I want to return, that does not go outside this closure
} catch let error as NSError {
print(error)
}
}
}.resume()
return returnip //Does not return anything
}
Thanks

Answer 1

You cannot return from an asynchronous function and a return statement inside a closure only returns from the closure itself.
You need to use a completion handler instead. Also, don't use force unwrapping of optionals/force casting optionals when parsing a network response.
func getJsonFromUrl(name: String, completion: #escaping (String?)->()) {
//use name variable just as you would in a normal function
let URL2 = "https://url.com/asd.php"
let url = URL(string: URL2)
URLSession.shared.dataTask(with:url!) { (data, response, error) in
if error != nil {
print(error as Any)
completion(nil)
} else {
do {
guard let parsedData = try JSONSerialization.jsonObject(with: data!) as? [String:Any] else { completion(nil); return }
guard let ips = parsedData["ip"] as? String else {completion(nil); return }
print("The IP is: " + ips) //Prints the value correctly
completion(ips)
} catch let error as NSError {
print(error)
completion(nil)
}
}
}.resume()
}
Then you can call it like this:
getJsonFromUrl(name: "Input", completion: { ips in
print(ips)
//you can only use the value inside the closure of completion
})