Difference between Kotlin coroutines vs Dart async/await vs Java threading

Overview

Three different approaches to asynchronous programming:

Comparison Table

suspend

async

await

Basic Examples

Java Threading

javaCopy
new Thread(() -> {
    String data = fetchData();
    runOnUiThread(() -> {
        updateUI(data);
    });
}).start();

Kotlin Coroutines

kotlinCopy
viewModelScope.launch {
    val data = withContext(Dispatchers.IO) {
        fetchData() // Suspends, doesn't block
    }
    updateUI(data) // Back on main thread
}

Dart async/await

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Future<void> loadData() async {
  final data = await fetchData();
  updateUI(data);
}

Parallel Execution

Java

javaCopy
ExecutorService executor = Executors.newFixedThreadPool(2);
Future<User> user = executor.submit(() -> fetchUser());
Future<List<Post>> posts = executor.submit(() -> fetchPosts());

User u = user.get(); // Blocking
List<Post> p = posts.get();

Kotlin

kotlinCopy
val user = async { fetchUser() }
val posts = async { fetchPosts() }

val u = user.await()
val p = posts.await()

Dart

dartCopy
final results = await Future.wait([
  fetchUser(),
  fetchPosts(),
]);

Performance

Recommendation: Use Kotlin Coroutines for Android, Dart async/await for Flutter, avoid raw Java threads.