Does Dart support parallel task execution?

Dart does not have full support for parallel thread execution within a single isolate — code runs in a single thread. However, Dart supports asynchronous programming using async/await and Future, which allows tasks to be performed efficiently without blocking the main thread.

For true parallelism in Dart, isolates are used — separate threads with their own memory and event loop. Isolates do not share memory, so data exchange is done via message passing.

Example of creating an isolate:

import 'dart:isolate';

void isolateFunction(SendPort sendPort) {
  // Perform heavy task
  int result = 0;
  for (int i = 0; i < 1000000; i++) {
    result += i;
  }
  sendPort.send(result);
}

void main() async {
  ReceivePort receivePort = ReceivePort();
  await Isolate.spawn(isolateFunction, receivePort.sendPort);

  receivePort.listen((message) {
    print('Result from isolate: $message');
    receivePort.close();
  });
}

Thus, parallel execution in Dart is achieved through isolates, and asynchrony — through Future and async/await.