import 'dart:math';
void main() {
print(getRandomString(5)); // 5GKjb
print(getRandomString(10)); // LZrJOTBNGA
print(getRandomString(15)); // PqokAO1BQBHyJVK
}
const _chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz1234567890';
Random _rnd = Random();
String getRandomString(int length) => String.fromCharCodes(Iterable.generate(
length, (_) => _chars.codeUnitAt(_rnd.nextInt(_chars.length))));