7. First C++ program, cont.

• 
      #include <iostream>
      int main()
      {
          std::cout << "Hello, World!";
          return 0;
      }
  
  

  The return 0; statement stops execution of the main function.

• The return passes numeric value zero back to the caller of our program -- the operating system.

• Zero indicates success.

• Non-zero usually represents a well-known error code , signalling an unusual termination condition of the program (for example, "not enough memory," or "bad input parameters," etc.)