UmairJibran

$array = [1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,];
array_sort($array);
$minAverage = $array[0] + $array[1] + $array[2] + $array[3] + $array[4] / 5;
$minAverage = $array[29] + $array[28] + $array[27] + $array[26] + $array[25] / 5;

UmairJibran

await Firestore.instance
  .collection('usersName')
  .document('dummydata')
  .delete();

UmairJibran

await Firestore.instance
  .collection('usersName')
  .document('dummydata')
  .updateData(
    {'name': '$newUserName'}
);

UmairJibran

 String name;
  DocumentSnapshot _doc = await Firestore.instance
      .collection('usersName')
      .document('dummydata')
      .get()
      .timeout(Duration(seconds: 10));
  (_doc.exists) ? name = _doc['name'] : name = null;

UmairJibran

await Firestore.instance
  .collection('usersName')
  .document('dummydata')
  .setData({'name': '$userName'})
  .timeout(Duration(seconds: 10)
);