Thread: Help i am under tremendous pressure to program

Post what you've got and then we'll help you fix it. We're not gonna write the assignment for you.

Originally Posted by Nokubonga

Hi
I am a second year IT student and i hav an assignment that requires me to use visual c++ i need to program a calculator extra marks will be given for the sqrt and other extra functions please help coz i am so stuck its scary
P.S. We are using Borland C++ Builder 4 please this assignment is due on Thursday!!!

Too easy:

Code:

#include <cstdlib>

int main()
{
  std::system ( "calc" );
}

Now, running that program I find that at my consulting fee of $250US per hour, for 5 seconds of effort you owe me .35 cents.

Originally Posted by Prelude

Too easy:

Code:

#include <cstdlib>

int main()
{
  std::system ( "calc" );
}

Prelude is that really a calculator? holy jesus lol damn im shocked!

where does it come from, i mean, i dont know what i mean lol.

edit: ok i tested that just out of curiosity and it doesnt work lol i get a error message and a warning message.

Code:

C:\Program Files\DevStudio\MyProjects\calc\calcu.cpp(6) : error C2653: 'std' : is not a class or namespace name
C:\Program Files\DevStudio\MyProjects\calc\calcu.cpp(7) : warning C4508: 'main' : function should return a value; 'void' return type assumed
Error executing cl.exe.

if i use

Code:

 using namespace std;

i get 2 errors and 1 warning

Code:

C:\Program Files\DevStudio\MyProjects\calc\calcu.cpp(2) : error C2871: 'std' : does not exist or is not a namespace
C:\Program Files\DevStudio\MyProjects\calc\calcu.cpp(6) : error C2653: 'std' : is not a class or namespace name
C:\Program Files\DevStudio\MyProjects\calc\calcu.cpp(7) : warning C4508: 'main' : function should return a value; 'void' return type assumed
Error executing cl.exe.

this computer im using right now has visual c++ 5.0 but ill test it again when i go home cuz i got 6.0 . but wow thats so simple, lol

>Prelude is that really a calculator?
It is on my system.

>where does it come from
I just asked system to query Windows (because the OP mentioned Borland which is a Windows compiler) and open the built in calculator program.

Anything older than Visual Studio .NET has awful namespace conformance. In particular, VS 6.0 doesn't recognize that the C standard library is also in the std namespace. This should work for you:

Code:

#include <cstdlib> // Or <stdlib.h> if it still doesn't work

int main()
{
  system ( "calc" );
  return 0;
}

>is this an example of orthogonality?
No, it's an example of a poor compiler developed before the standard was finalized.

or you could

Code:

#include <windows.h>  //You need shell32.lib for this one 

int main(void)
{
  char szPath[] = "C:\\WINDOWS\\system32\\Calc.exe";

  HINSTANCE hRet = ShellExecute(
        HWND_DESKTOP, //Parent window
        "open",       //Operation to perform
        szPath,       //Path to program
        NULL,         //Parameters
        NULL,         //Default directory
        SW_SHOW);     //How to open

  /*
  The function returns a HINSTANCE (not really useful in this case)
  So therefore, to test its result, we cast it to a LONG.
  Any value over 32 represents success!
  */

  if((LONG)hRet <= 32)
  {
    MessageBox(HWND_DESKTOP,"Unable to start program","",MB_OK);
    return 1;
  }

  return 0;
}