Java ThreadGroup activeCount() method
The activeCount() method of ThreadGroup class is used to return the number of active threads in the current thread's thread group. The returned value is only an estimate because the number of threads may change dynamically while this method traverses internal data structures.
It returns the number of active threads in the current thread's thread group.
ExampleTest it Now
Number of active thread: 3 Thread-1 completed executing Thread-2 completed executing Thread-3 completed executing