Dart Singleton Example

singleton_example.dart

import 'package:flutter/material.dart';

class State with ChangeNotifier {
  late num _count;
  num get count => _count;
  void setCount(newCount) {
    _count = newCount;
    notifyListeners();
  }

  State._internal() {
    _count = 0;
  }
  
  static final State _instance = State._internal();
  factory State() {
    return _instance;
  }
}

void main() {
  print('Creating state...');
  State state = State();
  state.setCount(5);
  print('Initial count: ${state.count}');

  print('Getting another instance...');
  State state2 = State();
  print('Singleton count: ${state2.count}');
}