How do I add Methods or Values to Enums in Dart?

by

Starting with Dart 2.6 you can define extensions on classes (Enums included).

enum Cat {
  black,
  white
}

extension CatExtension on Cat {

  String get name {
    switch (this) {
      case Cat.black:
        return 'Mr Black Cat';
      case Cat.white:
        return 'Ms White Cat';
      default:
        return null;
    }
  }

  void talk() {
    print('meow');
  }
}

Example:

Cat cat = Cat.black;
String catName = cat.name;
cat.talk();

Here’s one more live example (uses a constant map instead of a switch):
https://dartpad.dartlang.org/c4001d907d6a420cafb2bc2c2507f72c

More Related Contents:

  1. how to implement a main function in polymer apps
  2. How do I format a date with Dart?
  3. Passing data between screens in Flutter
  4. What is the difference between the “const” and “final” keywords in Dart?
  5. When should I use a FutureBuilder?
  6. Converting timestamp
  7. How to preserve widget states in flutter, when navigating using BottomNavigationBar?
  8. What are the ?? double question marks in Dart?
  9. Flutter setState to another class?
  10. Flutter get context in initState method
  11. How does the const constructor actually work?
  12. Flutter – Read text file from assets
  13. dart advantage of a factory constructor identifier
  14. Flutter Error: MediaQuery.of() called with a context that does not contain a MediaQuery
  15. What is the difference between “show” and “as” in an import statement?
  16. Enumerate or map through a list with index and value in Dart
  17. How do I build different versions of my Flutter app for qa/dev/prod?
  18. Creating function with variable number of arguments or parameters in Dart
  19. Flutter: Retrieving top-level state from child returns null
  20. How do I run a reoccurring function, in Dart?
  21. Instantiate a class from a string
  22. How can I read (from disk) and resize an image, in Flutter/Dart
  23. Implement an Observer pattern in Dart
  24. How to detect orientation change in layout in Flutter?
  25. how to access an object created in one stateful widget in another stateful widget in flutter
  26. How to force Flutter to rebuild / redraw all widgets?
  27. flutter – correct way to create a box that starts at minHeight, grows to maxHeight
  28. What’s a good recipe for overriding hashcode in Dart?
  29. Create and Run Dart Console Application Using VSCode?
  30. How does a set determine that two objects are equal in dart?

Leave a Comment