Is it really necessary to use "scan.close(); "? After usage of scanner in every program

Answer 1

If you do not close the scanner class it will generate warnings like Resource leak.

Resource leak happens when a program doesn't release the resources it has acquired. As OS have limit on the no of sockets,file handle,database conn etc thus its extremely important to manage these non-memory resources explicitly. So we explicitly call close() methods to free upresources

Answer 2

Thanks mate