Codable+Class.swift

class Animal : Codable {
    var type : String {
       return "animal"
    }
}

class Dog : Animal {
    override var type : String {
        return "dog"
    }
}

class Cat : Animal {
    override var type : String {
        return "cat"
    }
}

var array : [Animal] = [Dog(), Cat(), Dog(), Cat()];

array.forEach{ print($0.type) }

var data = try PropertyListEncoder().encode(array)
var restoreArray = try? PropertyListDecoder().decode(Array<Animal>.self, from: data)

restoreArray?.forEach{ print($0.type) }