Dart Academy · Lesson

Final Fields and Deep Immutability

Build objects that never change.

Immutable by Design

An immutable object never changes after it is built. That makes your data predictable and safe to share across your whole app. 🔒

A final field is set once, during construction, and can never be reassigned. It locks the value in place for the life of the object.

class Point {
  final int x;
  Point(this.x);
}