Use of local variable "" before its declaration error

Question

I get the above error when setting up GPS in Xcode at the lines with "locationManager". Not sure what to do. - edit- I cleaned the file and the error's were fixed until I added the func locationManager line outside of the viewDidLoad and the errors are back on the locationManager lines.

Code:

class ViewController: UIViewController, CLLocationManagerDelegate {

    // labels

    @IBOutlet var cityLabel: UILabel!
    @IBOutlet var tempratureLabel: UILabel!
    @IBOutlet var rainLabel: UILabel!
    @IBOutlet var windLabel: UILabel!
    @IBOutlet var humidityLabel: UILabel!
    @IBOutlet var backgroundColor: UIImageView!
    var locationManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()

        // USER GPS IN LAT/LON

        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestWhenInUseAuthorization()
        locationManager.startUpdatingLocation()

        // api
        let client = APIClient(apiKey: "xxxxxxxxxxxxxxxxxxxxxxxx")
        client.units = .Auto
        client.getForecast(latitude: -75, longitude: -26) { (currentForcast, error) -> Void in
            if let currentTemperature = currentForcast!.currently?.temperature {
                self.tempratureLabel.text = String(currentTemperature)
                let backgroundTemp = currentForcast!.currently?.temperature
                //update background image per temp
                if backgroundTemp <= 9  {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-GREY.png")
                } else if backgroundTemp >= 10 && backgroundTemp <= 19 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-DARKPURP.png")
                } else if backgroundTemp >= 20 && backgroundTemp <= 29 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-DARKBLUE.png")
                } else if backgroundTemp >= 30 && backgroundTemp <= 39 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-DGREEN.png")
                } else if backgroundTemp >= 40 && backgroundTemp <= 49 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-MIDPURP.png")
                } else if backgroundTemp >= 50 && backgroundTemp <= 59 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-MIDBLUE.png")
                } else if backgroundTemp >= 60 && backgroundTemp <= 69 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-LIGHTPURP.png")
                } else if backgroundTemp >= 70 && backgroundTemp <= 75 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-LIGHTBLUE.png")
                } else if backgroundTemp >= 76 && backgroundTemp <= 78 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-LGREEN.png")
                } else if backgroundTemp >= 79 && backgroundTemp <= 81 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6_YELLOW.png")
                } else if backgroundTemp >= 82  && backgroundTemp <= 87 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6_ORANGE.png")
                } else if backgroundTemp >= 88  && backgroundTemp <= 98 {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-LIGHTRED.png")
                } else {
                    self.backgroundColor.image = UIImage(named: "Gradient1_Iphone6-DARKRED.png")
                }
            }

            //update minor labels
            let rain = 10
            self.rainLabel.text = String(rain) + " %"
            let humidity = 10
            self.humidityLabel.text = String(humidity) + " %"
            let wind = 10
            self.windLabel.text = String(wind) + " mph"

            // Do any additional setup after loading the view, typically
        }

        func locationManager (manager: CLLocationManager! , didUpdateLocation locations: [AnyObject]!) {
            print(locations)
        }

        func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
            // Dispose of any resources that can be recreated.
        }
    }
}

Answer 1

I don't know if this would be helpful, but I had messed up the opening and closing braces of the function. Tried googling it before trying to debug it myself. Silly me!

Answer 2

For future reference:

When you are getting a weird error like

Use of local variable “” before its declaration error

you should realize that it's clearly not recognizing what you have typed (given that "" is not a variable name).

The solution is usually the good ol' turn-it-off-and-on (restart Xcode) or a clean CMD + Shift + K and build CMD + B.

Also, you added

func locationManager (manager: CLLocationManager! , didUpdateLocation locations: [AnyObject]!) {

inside of viewDidLoad. You'll need to move that outside.

Answer 3

class cat {
  var legs? = 4
  func manuallyCountLegs() -> Int {
    guard legs ?? 0 < 50 else {
      // Bail, I don't have time for this much counting
      return legs ?? 0
    }
    let legs = self.legs
    ...
  } 
}

This fails because it things the legs up top (which is perfectly fine if it refers to self.legs) was intended to use the local-scoped legs below.