Why the first Thread.activeCount() return 1 but another return 2 in my code?

Question

Here is my application:

public class NamedThread extends Thread {
    /* This will store name of the thread */

    String name;

    @Override
    public void r         


        

Answer 1

If we print all the threads then we can observe that default thread group is System and inside the system, there are different threads and groups like :

Group[system:class java.lang.ThreadGroup]
 Reference
  Finalizer
  Signal Dispatcher
  Group[main:class java.lang.ThreadGroup]
     main
     Monitor
  Group[InnocuousThreadGroup:class java.lang.ThreadGroup]
    Common-Cleaner

In java code default thread group is main. When we print active thread count then it will give an answer as 2 because the main thread group has two threads main and monitor.