In which cases is it necessary to implement a destroy method or similar to free resources in an object?

In Flutter, the dispose() method (similar to destroy) should be implemented to release resources that are not automatically managed by the garbage collector. This is relevant in cases such as:

• Controllers (e.g., TextEditingController, AnimationController) — need to be disposed to prevent memory leaks.

• Subscriptions to streams (StreamSubscription) — should be canceled to avoid receiving events after widget disposal.

• Timers and other asynchronous operations — should be stopped or canceled.

• Resources related to platform channels or native objects — should be released to prevent leaks.

Example:

class MyWidgetState extends State<MyWidget> {
  final TextEditingController _controller = TextEditingController();
  late final AnimationController _animationController;

  @override
  void initState() {
    super.initState();
    _animationController = AnimationController(vsync: this);
  }

  @override
  void dispose() {
    _controller.dispose();
    _animationController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

Thus, dispose() is needed for proper resource cleanup and to prevent memory leaks.