swift - Custom variable setter with a default value -

i cannot create custom setter default value simple class. want implement custom tz setter timezone inspecting.

what's wrong?

public class city: nsobject {     public var lat = 0.0, lon = 0.0, name = ""     private static let def_tz = "gmt+00:00"     private static let timezones = nstimezone.knowntimezonenames()     public var tz: string = def_tz {         set { //// <<<<< there error             var = city.timezones.indexof(newvalue ?? city.def_tz) ?? 0             self.tz = timezones[i].name         }         {             return self.tz         }     }     // mark:- init      required public init(name: string, lat: double, lon: double, tz: string) {         super.init()         setup(name, lat: lat, lon: lon, tz: tz)     }      private func setup(name: string, lat: double, lon: double, tz: string) {         self.lat = lat         self.lon = lon          self.tz = tz == "" ? city.def_tz : tz         self.name = name     }  } 

the error

city.swift:16:9: use of unresolved identifier 'set'

the syntax of custom setter wrong here.

check correct 1 here: https://developer.apple.com/library/prerelease/content/documentation/swift/conceptual/swift_programming_language/properties.html