Sealed classes in Java let developers limit the creation and use of subclasses and preserve the class hierarchy. Here is how sealed classes in Java work.

Compare inheritance and composition, the two fundamental ways to relate Java classes, then practice debugging ClassCastExceptions in Java inheritance.

The more familiar you are with Object and its methods, the more you can do with your Java programs.

Quickly learn how to use the Java ternary operator and see how this simple programming construct can help make your conditional logic, if statements and return statements clearer and more concise.