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

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 ...

There are benefits and drawbacks to Java's Iterator vs. ListIterator interface. Learn how to make the right choice when you choose between them.

Java also lets you declare interfaces inside of interfaces. In this case, a nested interface is a static member of its enclosing interface, and once again the static keyword is redundant.