What methods can be used to implement data exchange between fragments in an application?

Data exchange between fragments in Android can be implemented in several ways:

1. Through Activity — fragments pass data via the parent Activity, which acts as an intermediary.

2. Using ViewModel with LiveData — a shared ViewModel linked to the Activity allows fragments to observe data changes.

3. Callback interfaces — a fragment defines an interface that the Activity or another fragment implements to pass data.

4. EventBus (e.g., Otto, EventBus) — libraries for publishing and subscribing to events.

5. SharedPreferences or database — for more persistent storage and data exchange.

Example with ViewModel:

class SharedViewModel : ViewModel() {
    val selectedItem = MutableLiveData<String>()
}

// In the sender fragment
sharedViewModel.selectedItem.value = "Data"

// In the receiver fragment
sharedViewModel.selectedItem.observe(viewLifecycleOwner) { data ->
    // handle data
}