Where to Remove Observer for Nsnotification in Swift

Where to remove observer for NSNotification in Swift?

Use below method which functions same as dealloc.

deinit {
    // Release all resources
    // perform the deinitialization
}

A deinitializer is called immediately before a class instance is deallocated. You write deinitializers with the deinit keyword, similar to how intializers are written with the init keyword. Deinitializers are only available on class types.

Swift Deinitializer

How to removeObserver in Swift 5 using addObserver closure method

Set your observer object to current view controller.

From apple doc.s, object is

The object whose notifications the observer wants to receive; that is,
only notifications sent by this sender are delivered to the observer.

NotificationCenter.default.addObserver(forName: UIApplication.didBecomeActiveNotification,
                                       object: self,
                                       queue: nil) { [weak self] notification in
    guard let self = self else { return }
    self.loadWeather(notification.object)
}

Removing observer from NotificationCenter

deinit {
    NotificationCenter.default.removeObserver(self)
}

ANOTHER WAY

You can also make copy of Notification Observer object and remove it from NotificationCenter in deinit.

let notificationCenter = NotificationCenter.default
var loadWeatherObserver: NSObjectProtocol?

override func viewDidLoad() {
    super.viewDidLoad()
    loadWeatherObserver = notificationCenter.addObserver(forName: UIApplication.didBecomeActiveNotification,
                                                         object: nil,
                                                         queue: nil) { [weak self] notification in
        guard let self = self else { return }
        self.loadWeather(notification.object)
    }
}

deinit {
    if (loadWeatherObserver != nil) {
        notificationCenter.removeObserver(loadWeatherObserver!)
    }
}

Swift NotificationCenter remove observer quickest way

@Sh_Khan is right:

NotificationCenter.default.removeObserver(self)

You can get even further, as mentioned in the Apple Documentation:

If your app targets iOS 9.0 and later or macOS 10.11 and later, you don't need to unregister an observer in its dealloc method.

How to safely removeObserver (Swift)

I think you should use code

NSNotificationCenter.defaultCenter().removeObserver(self)

Explain:
You have mistake here: You are using NSNotification & NSNotificationCenter so you have to using this code above to remove observe.
you have use code for KVO to remove observer so it will wrong.

More detail you can read at here. Key-Value-Observing

NSNotificationCenter: Removing an Observer in Swift

When you use the 'blocks' based approach to observing notifications then self isn't in fact the observer. The function returns an object which acts as the observer:

func addObserverForName(_ name: String?,
                 object obj: AnyObject?,
                  queue queue: NSOperationQueue?,
             usingBlock block: (NSNotification!) -> Void) -> NSObjectProtocol

You need to keep a reference to this returned object and pass it in as the observer when you call removeObserver

It's explained well in the Apple Doc here

Best Place to Remove NotificationCenter Observer in Swift Struct

From iOS 9 and above, it's not necessary to remove NotificationCenter observers as they are automatically removed.

If you are concerned about observes stuck in memory anyway, you should call the removal from a class that is handling the struct.

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