Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...

As they exist outside the Java heap, the klasses do not require a Java object header, and they are not the same thing as the class objects used in reflection (which are genuine Java objects).

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.