Use Java's extends keyword to derive a child class from a parent class, invoke parent class constructors and methods, override methods, and more.

Create packages, import packaged classes and interfaces into your programs, move packages, and encapsulate them in jar files.

Why is the const keyword in Java not implemented? It's part of the language, but it can't be used to make a variable constant. Here's why const is included in Java, and why Java's const keyword is ...