When should I use static nested classes in Java?

What are static nested classes in Java?

Static nested classes are defined within another class and can access its static members. They don't require an instance of the outer class.

When should I use a static nested class instead of a regular class?

Use a static nested class when it logically belongs to the outer class and doesn't need access to instance variables of the outer class.

Can you give me an example of when to use a static nested class?

Sure! If you have a class that represents a complex data structure, like a Tree, and you want to define a Node class that only makes sense in the context of the Tree, a static nested class is appropriate.

Are there any performance benefits to using static nested classes?

Yes, static nested classes can improve performance by reducing memory overhead since they don't hold a reference to the outer class instance.