Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

Here's everything you need to know about initializing Java classes and objects before executing them in the JVM.

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.

For new Java programmers, the JOptionPane class is a great visual and user-friendly introduction to user input and Swing-based programming. Here's how to get started.