TypeCasting

gistfile1.txt

import Foundation 
//https://docs.swift.org/swift-book/LanguageGuide/TypeCasting.html
class MovieList {
    var name : String
    init(name: String) {
        self.name = name
    }    
}
class Movie: MovieList{
    var director: String
    init( name: String, director: String) {
        self.director = director
        super.init(name: name) 
    } 
}
class Artist: MovieList{
    var artist: String
    init(name: String, artist: String) {
        self.artist = artist
        super.init(name: name)         
    }    
}
let library = [
    Movie(name:"Alita : Battel angle", director: "James Cameron"),
    Artist(name: "Rosa Salazar", artist: "Jennifer Connelly")   , 
    Movie(name:"Avater", director: "James Cameron"),
    Artist(name: "Leo", artist: "Alexzerder")  ,
    Movie(name:"Alita : Battel angle", director: "James Cameron"),
    Artist(name: "Rosa Salazar", artist: "Jennifer Connelly")   , 
    Movie(name:"Avater", director: "James Cameron"),
    Artist(name: "Leo", artist: "Alexzerder"),
    Artist(name: "Leo", artist: "Alexzerder") 
]

var movieCount = 0
var  artistCount = 0


for item in library {
    if item is  Movie {
        movieCount += 1
    } else if item is Artist{
       artistCount += 1 
    }
}

for item in library{

    if let movie = item as? Movie{
        print("\(movie.name) & \(movie.director)")
    }
    print("-----------------------------------")
    if let artist = item as? Artist{
        print("\(artist.name) \(artist.artist)")
    }
}
 print("\(movieCount) \(artistCount)")