Additional Notes
Why does ‘permits’ in sealed classes matter in this design?
Track: Java
Topic: Language Upgrades
Focus: Pattern Matching
Java: Pattern Matching
Answer
It specifies which classes can extend the sealed class.
The 'permits' clause in a sealed class declaration lists the classes allowed to extend it, providing control over the class hierarchy. This ensures that only known subclasses are used, allowing for exhaustive pattern matching.
The 'permits' clause in a sealed class declaration lists the classes allowed to extend it, providing control over the class hierarchy. This ensures that only known subclasses are used, allowing for exhaustive pattern matching.
Topics: Java Language Upgrades Pattern Matching