create random string with numbers dart
import 'dart:math';
void main() {
print(getRandomString(5)); // 5GKjb
print(getRandomString(10)); // LZrJOTBNGA
print(getRandomString(15)); // PqokAO1BQBHyJVK
}
import 'dart:math';
String generateRandomString(int len) {
var r = Random();
const _chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz1234567890';
return List.generate(len, (index) => _chars[r.nextInt(_chars.length)]).join();
}