ios - What I am doing wrong with my CLLocation? -

i trying make simple app shows: latitude longitude horizontal accuracy altitude vertical accuracy location start

my code is:

@iboutlet weak var latitude: uilabel! @iboutlet weak var longitude: uilabel! @iboutlet weak var horizontalaccuracy: uilabel! @iboutlet weak var altitude: uilabel! @iboutlet weak var verticalaccuracy: uilabel! @iboutlet weak var distance: uilabel!  var locationmanager: cllocationmanager = cllocationmanager() var startlocation: cllocation!  @ibaction func resetdistance(sender: anyobject) {     startlocation = nil }  func locationmanager(manager: cllocationmanager!,     didupdatelocations locations: [anyobject]!) {     var latestlocation: anyobject = locations[locations.count - 1]      latitude.text = string(format: "%.4f",         latestlocation.coordinate.latitude)     longitude.text = string(format: "%.4f",         latestlocation.coordinate.longitude)     horizontalaccuracy.text = string(format: "%.4f",         latestlocation.horizontalaccuracy)     altitude.text = string(format: "%.4f",         latestlocation.altitude)     verticalaccuracy.text = string(format: "%.4f",         latestlocation.verticalaccuracy)       if startlocation == nil {         startlocation = latestlocation as! cllocation     }      var distancebetween: cllocationdistance =     latestlocation.distancefromlocation(startlocation)      distance.text = string(format: "%.2f", distancebetween) }    func locationmanager(manager: cllocationmanager!,     didfailwitherror error: nserror!) {  } 

and in viewdidload section:

locationmanager.desiredaccuracy = kcllocationaccuracybest     locationmanager.delegate = self     locationmanager.requestwheninuseauthorization()     locationmanager.startupdatinglocation()     startlocation = nil 

i keep getting error: on latitude.text line (everything hooked correctly)

fatal error: unexpectedly found nil while unwrapping optional value 

(lldb)

how go adding if let statements? can me find problem?

thanks!

welcome swift. can't anyobject. cast down this:

    let latestlocation = locations.last as! cllocation 

also, "everything hooked correctly", i'm not sure believe that; try doing println(latitude) make sure.

finally, code not going work:

locationmanager.requestwheninuseauthorization() locationmanager.startupdatinglocation() 

the problem authorization request asynchronous. possibly starting update locations before you've got authorization. have wait until have authorization before start asking updates.