Dynamic polymorphism is where a class overrides a superclass method or implements an interface. For example, any class may override the Object.toString() method and provide its own implementation, and this is known at compile time. However, for a simple Java program that instantiates a series of objects and calls their toString() method, the compiler does not consider the object references differently. Any differences in the objects' toString() implementations are only seen at runtime, so they are considered dynamic.

Here is an example of Dynamic Polymorphism that will develop suitable hierarchy, classes for Point, Shape, Rectangle, Square, Circle, Ellipse, Triangle, Polygon, etc.

class point{
void show(){
System.out.println("This is the Point Base class");
}
}
class shape extends point{
void display(){
System.out.println("Different shapes can be developed with different number of points");
}
}
class rectangle extends shape{
int l,b;
void getdata(int x,int y){
l=x;b=y;
}
void area(){
System.out.println("Length:"+l);
System.out.println("Breadth:"+b);
System.out.println("Area:"+(l*b));
}
}
class square extends shape{
int a;
void gdata(int x){
a=x;
}
void area(){
System.out.println("Side:"+a);
System.out.println("Area:"+(a*a));
}
}
class circle extends shape{
int r;
void get(int x){
r=x;
}
void area(){
System.out.println("Radius:"+r);
System.out.println("Area:"+(3.14*r*r));
}
}
class triangle extends shape{
int b,h;
void tdata(int x,int y){
b=x;h=y;
}
void area(){
System.out.println("Base:"+b);
System.out.println("Height:"+h);
System.out.println("Area:"+(0.5*b*h));
}
}
class ShapeTest{
public static void main(String args[]){
rectangle r = new rectangle();
square s = new square();
circle c = new circle();
triangle t = new triangle();
r.show();
s.display();
System.out.println("");
System.out.println("Rectangle:");
System.out.println();
r.getdata(12,6);
r.area();
System.out.println("");
System.out.println("Square:");
System.out.println();
s.gdata(7);
s.area();
System.out.println("");
System.out.println("Circle:");
System.out.println();
c.get(5);
c.area();
System.out.println("");
System.out.println("Triangle:");
System.out.println();
t.tdata(4,7);
t.area();
}
}

This is the Point Base class Different shapes can be developed with different number of points

Rectangle:

Length:12 Breadth:6 Area:72

Square:

Side:7 Area:49

Circle:

Radius:5 Area:78.5

Triangle:

Base:4 Height:7 Area:14.0