Create async_await_in_dart.dart

async_await_in_dart.dart

@@ -0,0 +1,25 @@
+import 'dart:async';
+
+const Duration delay = const Duration(milliseconds: 200);
+
+Future loadLastName(String firstName) {
+  return new Future.delayed(delay).then((_) {
+    return firstName + 'fest';
+  });
+}
+
+// Marking a function with 'async' will return a future
+Future loadLastName2(String firstName) async {
+  await new Future.delayed(delay);
+
+  return firstName + '.com';
+}
+
+main() async {
+  // 'await' will suspend execution of the function until the
+  var LastName3 = await loadLastName('Hacktober');
+  var LastName4 = await loadLastName2('Digitalocean');
+
+  print('open contribution by Ali in $LastName3');
+  print('$LastName4');
+}