This is my code: var art: Int = 0 @IBAction func art(_ sender: Any) {         art += 1         tutText = “artTut”         if art == 1{             print(art)             let storyBoard: UIStoryboard = UIStoryboard(name: “Art”, bundle: nil)             let newViewController = storyBoard.instantiateViewController(withIdentifier: “UITabBarController”)…

I’m reading Apple’s official Swift mannual (https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting.html#//apple_ref/doc/uid/TP40014097-CH20-ID48), and there’s something in the mannual that I don’t really understand.   class Country {   let name: String   var capitalCity: City!   init(name: String, capitalName: String) {   self.name = name   self.capitalCity = City(name: capitalName,…

I’m reading Apple’s Swift tutorial on ARC and there’s something that I don’t understand (link: https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting.html#//apple_ref/doc/uid/TP40014097-CH20-ID48)     class Country {   let name: String   var capitalCity: City!   init(name: String, capitalName: String) {       self.name = name       self.capitalCity = City(name: capitalName, country:…