I'm working through a learn-swift playground and upgrading it to Swift 2.0 as I learn the language. The following code (which likely worked with prior versions of Swift) now generates two errors: "'self' used before all stored properties are initialized" and "Constant 'self.capitalCity' used before initialized"
class Country
{
let name: String
let capitalCity: City!
init(name: String, capitalName: String)
{
self.name = name
self.capitalCity = City(name: capitalName, country: self)
}
}
class City
{
let name: String
unowned let country: Country
init(name: String, country: Country)
{
self.name = name
self.country = country
}
}
reading an answer to a similar question I see that I can change let capitalCity: City!
to var capitalCity: City!
and the syntax error is resolved.
I realize that in this contrived example a country's capital city can change, so that would be fine, but what if there were a case where the value really was a constant...
Is there any way to resolve the syntax error while keeping capitalCity a constant?
In this case I would suggest you to make the property a variable but hiding it (make it seem like a constant) through a computed property:
class Country {
let name: String
private var _capitalCity: City!
var capitalCity: City {
return _capitalCity
}
init(name: String, capitalName: String) {
self.name = name
self._capitalCity = City(name: capitalName, country: self)
}
}