Swift Language Type Casting Example of using a downcast on a function parameter involving subclassing
Example
A downcast can be used to make use of a subclass's code and data inside of a function taking a parameter of its superclass.
class Rat {
var color = "white"
}
class PetRat: Rat {
var name = "Spot"
}
func nameOfRat(🐭: Rat) -> String {
guard let petRat = (🐭 as? PetRat) else {
return "No name"
}
return petRat.name
}
let noName = Rat()
let spot = PetRat()
print(nameOfRat(noName))
print(nameOfRat(spot))
