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.

How does the open-closed SOLID principle work in a Java program? Here we show you what this important principle means, and how to implement the open-closed principle in Java.

Java’s interface language feature confuses many Java newbies. Many mistakenly assume that interfaces only sidestep Java’s failure to support multiple implementation inheritance. In reality ...

The functional consumer interface is a key part of the Java Streams API. Here is a simple Consumer interface example to show you how to use this Java component.

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