text: #include <iostream>
  
  //a function that demonstrates global variables
  int doStuff()
  {
      return 2 + 3;
  }
  
  
  //global variables are introduced like other variables
  int count_of_function_calls = 0;
  void fun ()
  {
      //and the global variable is available here
      count_of_function_calls++;
  }
  
  int main()
  {
      fun();
      fun();
      fun();
      //the global variable is accessible here
      std::cout << "Function fun was called "
      << count_of_function_calls << " times " << "\n";
  }
  