JAVA EE: Java Tutorial : Java Interface (Evolving Interfaces using extends)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=Ss_O-2CvJZ4&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial : Java Interface (Evolving Interfaces using extends)

DoIt.java

public interface DoIt
{
    void sayHi();
}

DoItPlus.java

public interface DoItPlus extends DoIt
{
    void sayBye();
}

MyClass.java

public class MyClass implements DoItPlus
{

    @Override
    public void sayHi()
    {
        System.out.println("Hi");

    }

    @Override
    public void sayBye()
    {
        System.out.println("Bye");
        
    }

}

InterfaceTest.java

public class InterfaceTest
{

    public static void main(String[] args)
    {
        DoItPlus doItPlusRef = new MyClass();
        doItPlusRef.sayHi();
        doItPlusRef.sayBye();
    }

}

Output