Thread question-no run() method signature

[Rob Kiu]

Hi everyone,
Code below compiled, executes and prints out nothing. My question is why b.run(); is OK when it was not overridden and class Bground does not implements Runnable. Thought it'll give compile error eg: if we call a method say b.test(); but did not define the method signature in the class eg void test(){};
Appreciate any help, thanks !!
Rob
From Marcus Green Mock : Question Bank Id:106, code added:b.test(); & comments

public class Bground extends Thread{
  public static void main(String argv[]){
     Bground b = new Bground();
           b.run();
   b.test()// compiler error msg: cannot resolve symbol       
  }
     
     public void start(){
                for (int i = 0; i <10; i++){
                        System.out.println("Value of i = " + i);
                }
     }
}

[Bijesh Krishnadas]

run() is a non-abstract method in Thread. Which is why u dont need to override the method in your class
Bijesh

[Sindhur Sat]

Reason:
Thread is a non abstract class that implements Runnable and run() is a public abstract method in Runnable; so guess what, Thread is forced to implement run() method; if you want you can override it in your extended class;In that case your run() method would have been executed in a new thread instead of the blank run() method of the Thread class.
Sindhur

[Rob Kiu]

Dear Bijesh, Sindhu,
Thanks for clearing that up. Look up the API to confirm, yes indeed Thread has a public void run method, whereas I thought only Runnable has the run method, so the code I quoted works!
From 1.4.2 API

run
public void run()
If this thread was constructed using a separate Runnable run object, then that Runnable object's run method is called; otherwise, this method does nothing and returns.
Subclasses of Thread should override this method.

Cheers,
Rob