In this Java 101 tutorial, I’ve explained how interfaces differ from classes, and showed you how to declare, implement, and extend interfaces in your Java programs.

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

Learn Java lambda syntax by comparing different approaches to implementing functional interfaces. The UnaryOperator function Like the Function interface, the UnaryOperator is passed a value and ...

If you want to take advantage of sorting methods in Java, you'll need to implement the Comparable interface. Written by David Petersheim, Contributor Feb. 17, 2005 at 8:00 a.m. PT ...