What are immutable objects?

Immutable objects are objects whose state cannot be changed after creation. Any operation that appears to modify such an object actually creates a new object with the modified state.

Advantages:

• Predictability: The object's state does not change unexpectedly.
• Thread safety: No need for locks when accessed from different threads, as the state cannot be changed.
• Debugging simplicity: Easier to track the object's state during execution.
• Optimizations: Some operations can be cached since the result will not change.

Examples in Dart/Flutter:

• Primitive types: int, double, bool, String.
• Classes created using the const keyword (to create constant instances that are immutable) or with final fields (to create unchangeable instances after initialization).

// Example of an immutable String object
String name = "Flutter";
// The following operation creates a new string, not changing 'name'
name = "Dart"; 

// Example of an immutable class with final fields
class Point {
  final int x;
  final int y;

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

// Creating an immutable instance
const Point origin = Point(0, 0);
// origin.x = 5; // Compilation error - final field cannot be changed