Can we use c++ to program a 3d printer ?

Answer 1

yes
have a look here for tutorials and source related to a CNC machine.
https://homofaciens.de

Answer 2

Can you give me some code for that? thanks

Answer 3

If we want to display 3D graphics in real-time, for instance in a game or 3D simulation, then we need a language and environment that runs fast and we also need efficient 3D libraries. Options: Use C++. There is quite a steep learning curve, because, not only do we have to learn C++ (the easy part!)