Errors thrown from here are not handled because the enclosing catch is not exhaustive

Question

Swift Errors Thrown from here are not handled

I followed the above link but i still seeing that issue. Adding code below

do {
    // print("\(v)")
    let jsonData = try NSJSONSerialization.dataWithJSONObject(["code":"102", "response":v], options: NSJSONWritingOptions.PrettyPrinted)
    let string: String! = String(data: jsonData, encoding: NSUTF8StringEncoding);
    print("\(string)")
    BonjourClient.sharedInstance.sendString(string)
}
catch let error as NSError {
    print(error)
}

Answer 1

Swift 5

enum MyError: Error {
    case somePattern
}

// … 

do {
    let jsonData = try JSONSerialization.data(withJSONObject: /*…*/)
} catch MyError.somePattern {
    print("Some specific known error type occured.")
} catch { // exhaustive. not constrained to any specific error
    print("Unexpected, not otherwise caught, error: \(error)")
}

Swift 4

enum MyError: Error {
    case somePattern
}

// … 

do {
    let jsonData = try NSJSONSerialization.dataWithJSONObject([/*…*/])
} catch MyError.somePattern {
    print("Some specific known error type occured.")
} catch { // exhaustive. not constrained to any specific error
    print("Unexpected, not otherwise caught, error: \(error)")
}

Note that error is available in the final catch clause example above.

See The Swift Programming Language Error Handling

If no pattern is matched, the error gets caught by the final catch clause and is bound to a local error constant.

Answer 2

The problem is that you missing an empty catch, and should add:

catch {
}