Help i am under tremendous pressure to program

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!!!

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

Quote:

---

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. :)

Quote:

---

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.

edit lol im still in shock, u got 6.0?

i did 1 change on ur prog Prelude, dont know if u misstyped it or anything but on visual c++ 5.0 the following code is correct

Code:

---

#include <cstdlib>


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

---

it does give the systems calc lmao holy jesus!

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;
}

---

hehe that also works, is this an example of orthogonality?

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

ooooh that makes sense eheheh

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;
}

---

Welcome Nokubonga,

You are NOT going to get credit for a program that opens the Windows calculator!!!!

I'm not sure what you're supposed to do. I can't tell if you are supposed to write a full-Windows GUI program, or a Windows Console (text-based) program.

Borland Builder makes it "easy" to do the GUI stuff... Well, it's supposed to... I've never actually done it the "easy way".

Visual C++ is a different compiler from a different company!!! It has MFC (Microsoft Foundation Classes) that also make it "easy" to write GUI programs.

In any case, you program is going to need some "if statements", some statements or functions to do the actual calculations, and some input & output statements (cin & cout if you're writing a console program.)

You should have enough information from your class notes and reading assignment to complete your homework, unless you signed-up for a class without having the prerequisites. (GUI programming in C/C++ is generally an advanced topic.)

Like, XSquared said, make an attempt. Show what you've done so far, and you'll get much more help here! See the announcements about homework, and board guidelines.

Hint - The <cmath> header includes a square root function.

Remember that the new headers such as <cmath> have all their elements in the std namespace which means you mean to do:

Code:

---

#include <cmath>

// A)
y = std::sqrt(x);

// B)
using std::sqrt;
y = sqrt(x);

// C)
using namespace std;
y = sqrt(x);

---

The last one (C) will include everything in the std namespace which includes all the math functions included in cmath.

If your compiler does not include the new standard headers, use math.h and don't worry about namespaces.