singletons in dart code example

Example 1: flutter singleton

class Singleton {
  static final Singleton _instance = Singleton._internal();

  factory Singleton() => _instance;

  Singleton._internal();
}

// Whenever you need to get the singleton, call its factory constructor, e.g.:
//   var singleton = Singleton();
//
// You'll always get the same instance.

Example 2: singleton classes in dart example

class Singleton {
  static Singleton _instance;

  Singleton._internal() {
    _instance = this;
  }

  factory Singleton() => _instance ?? Singleton._internal();
}