return & system.exit()

Is using "return" or "System.exit()" same if used in main() method ?

Thanks.

Returning from main() will only stop the program if no other non-daemon threads are running. So, for example, if the program has a GUI, then the event thread is running, so returning from main will not stop your program.

System.exit() will, however, stop your program no matter how many threads are running.

Thanks for the reply.
If I am validating the arguments passed to the program, should I use system.exit() or return, if the arguments are invalid.

Thanks.

System.exit() is a more abrupt way to stop your program. For example, if you call System.exit() from a try or catch block, any finally clause is ignored. System.exit() may be the most practical was to stop applications like Java Swing that have never-ending non-daemon threads.

If it was me, I'd display some friendly message to the user saying what argument(s) was bad and why, then return from the main method.

When in doubt, use return. It cleans up better before shutting down.

The nice thing about System.exit() is that you can pass an error code that, if the JVM is set up correctly for the O/S, it should pass to whomever called your program. This is why in C main() returns int.