Additional Notes
Why does the ‘non-sealed’ keyword in a sealed class hierarchy matter in this design?
Track: Java
Topic: Language Upgrades
Focus: Sealed Classes
Java: Sealed Classes
Answer
It allows a subclass to be non-restrictive in its subclasses.
The 'non-sealed' keyword is used to allow a subclass of a sealed class to have unrestricted subclassing. This provides flexibility in the hierarchy when needed. For instance, if `PayPal` is a subclass of a sealed class `Payment`, marking it as 'non-sealed' would allow further extensions without restrictions, unlike other subclasses which remain controlled.
The 'non-sealed' keyword is used to allow a subclass of a sealed class to have unrestricted subclassing. This provides flexibility in the hierarchy when needed. For instance, if `PayPal` is a subclass of a sealed class `Payment`, marking it as 'non-sealed' would allow further extensions without restrictions, unlike other subclasses which remain controlled.
Topics: Java Language Upgrades Sealed Classes