Java SE 15 (Sept 2020) introduces sealed classes as a preview feature ... sealed interface Shape permits Circle, Rectangle { ... } Here we see how sum and product types go together; we are ...

class Rectangle { int height; int width ... To write SOLID code, and properly implement the Liskov substitution principle in Java, your code must be philosophically and behaviorally compliant as well.

Java interfaces are different from classes, and it’s important to know how to use their special properties in your Java programs. This tutorial introduces the difference between classes and ...

I'm learning Java by writing a Mandelbrot program. I can draw the image, then use the mouse to choose an area to magnify. Works great, except... When I choose the area to magnify (mouse down, move ...