ThinkDigitalSoftware · April 6, 2020 20:21 · Apr 6, 2020
diff --git a/main.dart b/main.dart
@@ -0,0 +1,24 @@
+import 'dart:async';
+
+final Completer<int> halfwayPointCompleter = Completer();
+
+void main() async {
+  print('getting started');
+  calculateSomeNumbers(10).then((result) => print(result)); // async
+  int halfwayPoint = await halfwayPointCompleter.future;
+  print(halfwayPoint);
+  // this will print before the above function completes because it's waiting for the //halfwayPointCompleter to complete, which completes halfway through
+}
+
+//function is useless, but it's just an example.
+Future<int> calculateSomeNumbers(int max) async {
+  for (int i = 0; i < max; i++) {
+    await Future.delayed(Duration(milliseconds: 500));
+    if (i == max ~/ 2) {
+      // ~/ is division with rounding. It returns an int.
+      halfwayPointCompleter
+          .complete(i); // this makes the future return at this point.
+    }
+  }
+  return max;
+}