Java program using interface

In this tutorial, we are going to write a Java program using the interface in Java Programming with practical program code and step-by-step full complete explanation.

Java program using the interface.

 
public interface Speaker
{
    public void speak();
}
public class Lecturer implements Speaker
{
    public void speak()
    {
        System.out.println("Lecturer view");
    }
}

public class Politician implements Speaker
{
    public void speak()
    {
        System.out.println("Politician view");
    }
}

public class Test
{
    public static void main(String arr[])
    {
        Speaker sp=null;
        System.out.println("sp point to politician");
        sp=new Politician();
        sp.speak();

        System.out.println("sp point to Lecturer");
        sp=new Lecturer();
        sp.speak();
    }
}

Output

 
sp point to politician
Politician view
sp point to Lecturer
Lecturer view