Nesting classes is one way to better organize your code. For example, say you have a non-nested class ... For example, the Matcher class, in java.util.regex, provides a results() ...

By allowing developers to define closed hierarchies, sealed classes improve code safety, clarity and maintainability. Sealed classes make Java an even more powerful and expressive language and set the ...

They also appear in other parts of Java, like java.lang.Class, java.lang.Comparable, and java.lang.ThreadLocal. Before generics, Java code often lacked type safety. Here’s an example of Java ...