Step 1 - scheduleMicrotask

import 'dart:async';

void main() {
  print('1');
  scheduleMicrotask(() => print('3'));
  Future(() => print('4'));
  print('2');
}

• Typical output: 1, 2, 3, 4. Microtasks drain before the next event-queue task.

Step 2 - Why it exists

• Some APIs schedule follow-up work that should run before other timers or I/O to keep internal invariants.
• Most application code should prefer async/await and Future over sprinkling microtasks.

Step 3 - Future.microtask

Future<void> main() async {
  print('a');
  Future.microtask(() => print('c'));
  print('b');
}

Good habit

• If ordering surprises you, log with timestamps; avoid relying on microtask ordering across packages.

Practice tasks

• Interleave scheduleMicrotask, Future(() {}), and Future.microtask and sketch the print order before running.
• Find one Flutter or SDK API doc that mentions microtasks and note when they say to use them.