For pure C++
You can’t. C++ doesn’t even have the concept of a console.
The program could be printing to a printer, outputting straight to a file, or being redirected to the input of another program for all it cares. Even if you could clear the console in C++, it would make those cases significantly messier.
See this entry in the comp.lang.c++ FAQ:
- https://isocpp.org/wiki/faq/input-output#clear-screen
OS-Specific
If it still makes sense to clear the console in your program, and you are interested in operating system specific solutions, those do exist.
For Windows (as in your tag), check out this link:
- How do we clear the console in assembly?
Edit: This answer previously mentioned using system("cls");, because Microsoft said to do that. However it has been pointed out in the comments that this is not a safe thing to do. I have removed the link to the Microsoft article because of this problem.
Libraries (somewhat portable)
ncurses is a library that supports console manipulation:
- http://www.gnu.org/software/ncurses/ (runs on Posix systems)
- http://gnuwin32.sourceforge.net/packages/ncurses.htm (somewhat old Windows port)