Mark's coding playground...

what is an Interface? An interface is a collection of abstract methods. A class implements an interface, thereby inheriting the abstract methods of the interface. An interface is not a class. Writing an interface is similar to writing a class, but they are two different concepts. A class describes the attributes and behaviors of an object. An interface contains behaviors that a class implements. Unless the class that implements the interface is abstract, all the methods of the interface need to be defined in the class. MainActivity.java public class MainActivity extends Activity implements Interface { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } @Override public void testFunctionOne() { System.out.println("Print from testFunctionOne in the Interface"); } @Override public void testFunctionTwo() { Syst...