Program to explain Polymorphism in Java

//  Program to explain Polymorphism or 
//  Dynamic Method Dispatch or Run Time Binding.
class  Shape
{
void draw()
{
 System.out.println("Drawing Shape.");
}
}
class  Rectangle extends Shape
{
void draw()
{
 System.out.println("Drawing Rectangle.");
}
}
class  Triangle extends Shape
{
void draw()
{
 System.out.println("Drawing Triangle.");
}
}
class  PolymorphismTest6
{
public static void main( String args[ ] )
{
 Shape s = new Shape();
 s.draw();
 
 Rectangle r = new Rectangle();
 s = r;
 s.draw();
 
 Triangle t = new Triangle();
 s = t;
 s.draw();
}
}
 
Output:  
Drawing Shape.
Drawing Rectangle.
Drawing Triangle.