Abstract Class and Constructor doubt

[Yogendra Joshi]

Hello All,

Today i was interviewed and didnt get selected, however i took this interview as a learning curve for myself. One of the tricker question being asked to me at the interview was "In an abstract class, do you have a constructor ? If yes, since we cannot instantiate Abstract class, wont that code be unreachable?"

I got confused at that question and when i came home and researched, I came to know that Every class including abstract class does have a constructor and its called when the Object of its implementation class is created. So for testing this out, I wrote a small code to verify my understanding.

Here's what i coded :

YNJAbstract.java

  public abstract class  YNJAbstract
{
	
	YNJAbstract()
	{
		System.out.println("Yogendra");
	}
}  

Implementation Class : YNJTest.java

  class YNJTest extends YNJAbstract
{
	public static void main(String[] args) 
	{
		abc a = new abc();
	}
}
  

Understand was correct, however my code landed in a problem and here's the output...


Yogendra
Yogendra
Yogendra
.
.
.

Exception in thread "main" java.lang.StackOverflowError

Can someone please explain me what wrong i did in this code?

Thanks in advance,
Yogendra N Joshi

[Campbell Ritchie]

You have somehow created an endless recursion, hence the Stack Overflow. It is not obvious how; the code you have posted doesn't appear to be the code you are running.

[Muhammad Khojaye]

http://stackoverflow.com/questions/260666/abstract-class-constructor-in-java

[Yogendra Joshi]

Hi,

Thanks for the help. Actually the class name should have been YNJTest while invoking and i somehow mistakenely gave abc while making new.

Its resolved now. This can be closed.

Thanks a lot.
Yogendra