Abstract classes and interfaces are plentiful in Java code, and even in the Java Development Kit (JDK) itself. Each code element serves a fundamental purpose: Interfaces are a kind of code ...

Although abstract classes and interfaces seem similar in some ways, ... By programming to an interface instead of its implementations, you can work with abstractions in lieu of concrete classes.

Abstract methods can also be used to specify interfaces for some programming languages. Abstract classes vs. interfaces. An interface is another similar way to create an abstraction. Like abstract ...