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.

But how many developers understand how HashMap works internally? A few days ago, I read a lot of the source code for ...

Java lets you declare interfaces inside of classes. Once declared, an interface is automatically a static member of the class. There is no need to declare the interface with the static keyword.

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

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, ...

The implementation of Java 8 Lambda expressions required an introduction to a number of new interfaces with esoteric names that can be somewhat intimidating to developers without any experience in ...