Explain the concept of an immutable class and its features

An immutable class is a class whose instances cannot be changed after creation. Features of an immutable class:

• All fields are declared as final and initialized in the constructor.
• The class is usually declared as final or does not provide methods to modify its state.
• If the fields are objects, they should also be immutable or copied upon transfer.

Advantages:

• Thread safety without additional synchronization.
• Simplicity of understanding and usage.

Example of an immutable class in Dart (Flutter):

class Point {
  final double x;
  final double y;

  const Point(this.x, this.y);
}

Here, after creating a Point object, its coordinates cannot be changed.