android-kotlin-coroutines

Kotlin coroutines provide structured concurrency for Android by launching tasks in viewModelScope, which automatically cancels work when the ViewModel is destroyed. Use Dispatchers to route IO, network, and database operations off the main thread, then expose results via StateFlow for reactive UI updates.

Flow is a cold, one-to-many stream that emits values only when collected and starts fresh for each collector. StateFlow is a hot, state-holding variant that always has a current value, replays it to new collectors, and is ideal for UI state that must persist across configuration changes.

Launch a coroutine in viewModelScope to fetch data on the IO Dispatcher, then emit results to a StateFlow. Collect the StateFlow in your UI layer to observe state changes and update views automatically without manual subscription management.

No. viewModelScope automatically cancels all launched coroutines when the ViewModel is cleared, eliminating memory leaks and dangling operations. Avoid GlobalScope and lifecycle scopes; always use viewModelScope in ViewModels.

Yes. Coroutines support try-catch blocks within suspend functions, and Flow operators like catch and retry handle errors and backpressure. Emit error states to StateFlow so the UI can display failures and allow user-initiated retries.

Use Dispatchers.IO for network and database calls, Dispatchers.Main for UI updates, and Dispatchers.Default for heavy CPU work. Coroutines switch Dispatchers transparently; withContext(Dispatcher) changes context within a coroutine without blocking.