How to Remove a Previous ViewController

Question

I am a student and pretty new to programming. I am trying to learn Objective-C/Swift in my spare time. I made a game using spriteKit with swift that has multiple menus/scenes. <

Answer 1

As I can assume, view controller being presented on the screen was instantiated either automatically from main storyboard or by setting app's window.rootViewController property.

In either case you can set rootViewController again to be your vc. To change rootViewController of your app you need to replace this line of code:

self.presentViewController(vc, animated: true, completion: nil)

... with one of the options bellow.

"Navigate" without transition animation:

Objective-C

UIWindow *window = (UIWindow *)[[UIApplication sharedApplication].windows firstObject];
window.rootViewController = vc;

Swift

let window = UIApplication.sharedApplication().windows[0] as UIWindow;
window.rootViewController = vc;

"Navigate" with transition animation:

Objective-C

UIWindow *window = (UIWindow *)[[UIApplication sharedApplication].windows firstObject];
[UIView transitionFromView:window.rootViewController.view
                    toView:vc.view
                  duration:0.65f
                   options:UIViewAnimationOptionTransitionCrossDissolve // transition animation
                completion:^(BOOL finished){
                    window.rootViewController = vc;
                }];

Swift

let window = UIApplication.sharedApplication().windows[0] as UIWindow;
UIView.transitionFromView(
    window.rootViewController.view,
    toView: vc.view,
    duration: 0.65,
    options: .TransitionCrossDissolve,
    completion: {
        finished in window.rootViewController = vc
    })

Remarks: Once rootViewController value gets changed your original view controller reference count should became 0 hence it will be removed from the memory!