Learn the difference between classes and interfaces once and for all, then get started declaring, implementing, and extending interfaces in your Java programs ...

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.

Compared with the traditional methods for interface creation, there's no debate that lambda expressions are much more concise. Here is the full Java Predicate example implemented with a lambda ...

If you want to take advantage of sorting methods in Java, you'll need to implement the Comparable interface.