Thread: Objects getting me down...:(

Code:

int Subtract(void) {return (x-y);}

... x, y are not declared. I think you meant ...

Code:

int Subtract(void) { return s1 - s2; }

Also, use this instead of those old headers:

Code:

#include <iostream>
using namespace std;

You'll also need to change this:

Code:

void CSubtraction::Equalize(int x, int y)
{
  x = s1;
  y = s2;
}

To this:

Code:

void CSubtraction::Equalize(int x, int y)
{
  s1 = x;
  s2 = y;
}

Originally posted by KneeLess
I've seen this before. Why should I use it? And some people tell me that it pollutes the namespace. Is that true?

Code:

#include <iostream.h>

is essentially the same as

Code:

#include <iostream>
using namespace std;

The second form wraps the header into the 'std' namespace. To avoid "polluting" the namespace, you can import separate pieces with the 'using' directive:

Code:

#include <iostream>
using std::cout;
using std::endl;

Or, you can just tag 'std::' onto the front of the identifiers:

Code:

#include <iostream>
....
  std::cout << "hello world" << std::endl;

Also, the header files that end in '.h' are deprecated. Standard conforming compilers are not required to provide them.