Any "void" parameter api's?

I'm looking to test invocation of native Win api's from Java and I don't know if I'm passing the correct datatypes. Are there any api's that take no parameters and perhaps return no parameters (but do something that I can see if the invocation worked)?

void someAPI(void); or
void someAPI(); or maybe even
int someAPI(void); or
int someAPI(); or possibly
void someAPI(int); or
int someAPI(int);

DWORD GetLogicalDrives(VOID)
HWND GetDesktopWindow(VOID)
or
VOID Sleep(
DWORD dwMilliseconds // sleep time in milliseconds
);

Thanks.