Classes and calling the properties Dynamically, Swift - ios

Question

I have two swift classes with two fairly similar properties (I have made the ones below the same for the purpose of this question) I want to use. I want to call the properties dynamically in the ViewDidLoad and I have used an array as shown below so I can change the index and choose which class to call. Unfortunately I get the error
Anyobject does not have a member named speciesType
What could I have missed or am I approaching the whole problem in the wrong way?
class Lion {
var age = 45
var speciesType = "Felidae"
}
class Lioness {
var age = 10
var speciesType = "Panthera"
}
var animal1 = Lion()
var animal2 = Lioness()
var animalKingDom = [animal1, animal2]
var colourChanging = animalKingDom[0].speciesType

Answer 1

Why dont you create a protocol that extracts out the common properties from both the classes.
class Lion {
var age = 45
var speciesType = "Felidae"
}
class Lioness {
var age = 10
var speciesType = "Panthera"
}
protocol LionType {
var speciesType: String { get set }
var age: Int { get set }
}
extension Lion: LionType { }
extension Lioness: LionType { }
var animal1 = Lion()
var animal2 = Lioness()
var animalKingDom: [LionType] = [animal1, animal2]
var colourChanging = animalKingDom[0].speciesType
I created a protocol LionType and added extension to both the classes to conform to the protocol. Since both the classes already have age and speciesType, the classes will remain unchanged. And finally, a small modification to your animalKingDom array could make it work easily.
By the way, I added a protocol LionType, I think it makes more sense to name it AnimalType which fits for all animals not just lions :)

Answer 2

I prefer the syntax where you declare the protocol before the classes, and let the classes explicit implement the protocol upon creation.
import Cocoa
protocol Animal {
var age: Int { get set }
var speciesType: String { get set }
}
class Lion: Animal {
var age: Int
var speciesType: String
init(age: Int, speciesType: String) {
self.age = age
self.speciesType = speciesType
}
}
class Lioness: Animal {
var age: Int
var speciesType: String
init(age: Int, speciesType: String) {
self.age = age
self.speciesType = speciesType
}
}
var l1 = Lion(age: 5, speciesType: "Cat")
var l2 = Lioness(age: 6, speciesType: "Doge")
var animalArray: [Animal] = [l1, l2]
for animal in animalArray {
print(animal.age)
print(animal.speciesType)
}
Also I'm not sure I would give a class for both male and female of an animal. But it totally depends on your business domain.

Answer 3

The compiler infer that the generic type of your array is 'AnyObject'.
Try removing one element from your array, and the compiler will find the good type of your array.
The compiler is not able to know that Lion and Lioness has a property in common.
You can either make a superclass or a protocol like GeneratorOne suggests.

Answer 4

I think that what you really want to do is have two instances of a single class (or better yet, if your real example is anything like this one, a struct). Let's keep using your Lion class. Two instances would then be
var lion = Lion()
lion.age = 45
lion.family = "Felidae"
var lioness = Lion()
lioness.age = 10
lioness.family = "Panthera"
(I'm ignoring the fact that your male and female are in different families. :))