Let’s build a simple function with no input and no output. We can do that?

Enter the void specifier, which is added in the function declaration before the function name. A void function, also known as a subroutine, has no return value, making it ideally suited for situations where you just want to print stuff to the terminal.

For example:

void animal_chat() {

  std::string fav, pet;

  std::cout << "What's your favorite animal?\n";
  std::cin >> fav;

  std::cout << "Do you have a " << fav << " as a pet? y/n\n";
  std::cin >> pet;

  if (pet == "y") {

    std::cout << "How lucky you have a " << fav << " as a pet!\n";

  } else {

    std::cout << "That's too bad.\n";

  }

}

The above chat program is built to capture user responses and print to the terminal without returning any values.