About Dynamic Polymorphism

Question

0.00/5 (No votes)

See more:

Hi EveryOne,

I had following question.

Java

Class A{
public void Test(){
System.out.println("In A Class Test Method");
}
}

Class B extends A{
public void Test(){
System.out.println("In B Class Test Method");
}
}
Class MainMethod{
public static void main(String [] args){
A a = new B();
 a.Test();//This will call the B class Test Method
}
}
}

In the above example which is a dynamic polymorphism case the method to be called is decided by the object created(in above case B Class Test Method will be called since I create B Class Object).Now I want to call the method of A Class without making any changes to the code.Is it possible?If not then how it can be said to be dynamic polymorphism as by seeing the object created we can easily say tha B Class Test Method wil be called

Thanks

Posted 7-Apr-13 21:21pm

LaxmikantYadav

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Shubhashish_Mandal · Accepted Answer · 2013-04-07T23:36:00

first of all you have to understand the meaning of dynamic polymorphism. The behaviour of the Object should be determined at runtime. In your code , by only watching the following line ,

Java

a.test();

, one can't predict which method can be called. However as per your simple example , you can easily say that it might call Class B's test() method , But think it little bit in large scenario. Suppose Class A has lots of sub classes,say Class B, Class C, .. Class N and there is a method something like :

Java

public void getResult(A object){
  //some code
  object.test();//say line no 3
  //some code
}

In this example can you able to say which test() method should be called. So no body can predict.
This can only be determined at runtime.