How to handle the no connection ports in a module?

In some cases, I want to leave some input or output ports of a module no connection. E.g.:

ModuleA modulea_1 (.in1(),.in2(),……,.out1(),.out2(),……);

However, if I just program as above, to leave them blank, it will gives me warnings or even causes malfunction of the module.

So I wonder how to handle these no connection ports? Please explain separably, for input, and output.

If you can answer this same question but for VHDL programming, that will be great.

Thanks a lot!