Additional Notes
When should you use the ‘permits’ keyword?
Track: Java
Topic: Language Upgrades
Focus: Sealed Classes
Java: Sealed Classes
Answer
Use it to specify allowed subclasses of a sealed class.
The 'permits' keyword is used in a sealed class declaration to list the specific subclasses that are allowed to extend it. This is crucial for maintaining control over the class hierarchy. For instance, if you have a sealed class `Transaction`, using 'permits' ensures that only `CreditTransaction` and `DebitTransaction` can inherit from it, preventing unauthorized subclasses.
The 'permits' keyword is used in a sealed class declaration to list the specific subclasses that are allowed to extend it. This is crucial for maintaining control over the class hierarchy. For instance, if you have a sealed class `Transaction`, using 'permits' ensures that only `CreditTransaction` and `DebitTransaction` can inherit from it, preventing unauthorized subclasses.
Topics: Java Language Upgrades Sealed Classes