DART

flutter How to dispose subscription

class EventNotifier extends ValueNotifier<List<String>> {
  // Omitted

  @override
  void dispose() {
    streamSub.cancel();
    super.dispose();
  }
}

dispose in flutter widget

Dart does not have destructors. 
Objects are automatically garbage collected when no longer referenced

In flutter we can do like for widget dispose:

@override
void dispose() {
	// your dispose part
	super.dispose();
}

dispose flutter

dispose method used to release the memory allocated to variables when 
state object is removed.

For example, if you are using a stream in your application then you 
have to release memory allocated to the stream controller. Otherwise,
your app may get a warning from the PlayStore and AppStore about memory 
leakage.