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.

Implementing Interfaces: When a class implements an interface, you can think of the class as signing a contract, agreeing to perform the specific behaviors of the interface. If a class does not ...

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

The functional Predicate interface gets used extensively by the Java 8 Streams API. Any developer who wants to master functional programming in Java will need to be comfortable with the Predicate ...

A great deal of Java programming -- from conditional statements to iterative loops -- deals with the evaluation of true or false values. When you work with the JDK's Streams API and Lambda functions, ...