When default methods were introduced in Java 8, some developers thought they would be the same as abstract classes. That’s not true, however, because interfaces can’t have state. A default ...

public abstract class Ellipse2D extends RectangularShape ... Declaring a local class within an enclosing class instance method (EnclosingClass.java, version 3) class EnclosingClass { void ...

protected and private concrete methods, while interfaces have all fields as automatically public, static and final. Interfaces, however, support multiple inheritances where abstract classes don't.

Instance main methods and unnamed classes, coming in Java 21, will forever change how developers learn Java and bootstrap applications. Why? They provide a simple, clean and concise syntax to launch ...