How to add an error statement

[w00t]

How do I add a statement so that when i input a number other than 1-5, the program doesn't fly into a tangent and instead gives an error message?
Also, is there anything cool that I can add to this program to make it better?

#include <iostream.h>

typedef unsigned short int USHORT;
typedef unsigned long int ULONG;
enum BOOL {FALSE, TRUE};
enum CHOICE {DrawRect = 1, GetArea,
   GetPerim, ChangeDimensions, Quit};
// Rectangle Class Declaration
class Rectangle
{
   public:
   //constructors
   Rectangle(USHORT width, USHORT Height);
   ~Rectangle();

   //accessors
   USHORT GetHeight() const { return itsHeight;}
   USHORT GetWidth() const  { return itsWidth; }
   ULONG GetArea () const  { return itsHeight * itsWidth; }
   ULONG GetPerim () const { return 2*itsHeight + 2*itsWidth; }
   void SetSize (USHORT newWidth, USHORT newHeight);

   // Misc. Methods
   void DrawShape() const;

   private:
     USHORT itsWidth;
     USHORT itsHeight;
};

//Class method implementations
 void Rectangle::SetSize(USHORT newWidth, USHORT newHeight)
{
   itsWidth = newWidth;
   itsHeight = newHeight;
}


Rectangle::Rectangle(USHORT width, USHORT height)
{
   itsWidth = width;
   itsHeight = height;
}

Rectangle::~Rectangle() {}

USHORT DoMenu();
void DoDrawRect(Rectangle);
void DoGetArea(Rectangle);
void DoGetPerim(Rectangle);

void main()
{
  //initalize a rectangle to 10,20
  Rectangle theRect(30,5);

  USHORT choice = DrawRect;
  USHORT fQuit = FALSE;

  while (!fQuit)
  {
    choice = DoMenu();
    if (choice < DrawRect || choice > Quit)
    {
      cout <<"\nInvalid Choice, please try again.\n\n";
      continue;
   }
   switch (choice)
   {
   case DrawRect:
     DoDrawRect(theRect);
     break;
   case GetArea:
     DoGetArea(theRect);
     break;
   case GetPerim:
     DoGetPerim(theRect);
     break;
   case ChangeDimensions:
     USHORT newLength, newWidth;
     cout <<"\nNew width:";
     cin  >> newWidth;
     cout << "New Height: ";
     cin  >> newLength;
     theRect.SetSize(newWidth, newLength);
     DoDrawRect(theRect);
     break;
   case Quit:
     fQuit = TRUE;
     cout <<"\nExiting...\n\n";
     break;
   default:
     cout <<"Error in choice!\n";
     fQuit = TRUE;
     break;
     }  //end switch
   }    //end while
}       //end main


USHORT DoMenu()
{
  USHORT choice;
    cout <<"\n\n***Menu*** \n";
    cout <<"(1) Draw Your Rectangle\n";
    cout <<"(2) Area\n";
    cout <<"(3) Perimeter\n";
    cout <<"(4) Resize\n";
    cout <<"(5) Quit\n";

 cin >> choice;
 return choice;
}

void DoDrawRect(Rectangle theRect)
{
  USHORT height = theRect.GetHeight();
  USHORT width = theRect.GetWidth();

  for (USHORT i = 0; i<height; i++)
   {
     for (USHORT j = 0; j<width; j++)
    cout <<"*";
    cout<< "\n";
  }
}


void DoGetArea (Rectangle theRect)
{
  cout <<"Area: " <<theRect.GetArea() << endl;
}

void DoGetPerim (Rectangle theRect)
{
cout <<"Perimeter: " <<theRect.GetPerim() << endl;
}

:rock:

[redhead]

I think I made an answer to a question like this..
In your DoMenu() make a check for what you have read, see this thread on what we came up with last:
http://www.codenewbie.com/forum/show...=&threadid=253

[w00t]

Man I hate Kdevelop. Borland may be in windows, but it's worth it.

[w00t]

Cool. So can i just throw that statement in anywhere in my program?
Pardon my ignorance

[redhead]

As your DoMenu() is made now, it looks like:

USHORT DoMenu()
{
  USHORT choice;
    cout <<"\n\n***Menu*** \n";
    cout <<"(1) Draw Your Rectangle\n";
    cout <<"(2) Area\n";
    cout <<"(3) Perimeter\n";
    cout <<"(4) Resize\n";
    cout <<"(5) Quit\n";

 cin >> choice;
 return choice;
}

If you wan't to be sure, it only returns with an integer within the 1 - 5 selection, then make it:

USHORT DoMenu()
{
  USHORT choice = 0;
   while(choice < 1 || choice > 5)
   {
      cout <<"\n\n***Menu*** \n";
      cout <<"(1) Draw Your Rectangle\n";
      cout <<"(2) Area\n";
      cout <<"(3) Perimeter\n";
      cout <<"(4) Resize\n";
      cout <<"(5) Quit\n";
      cin >> choice;
      if(choice < 1 || choice > 5)
          cout << "Sorry your choice of (" << choice
                  << ") is not within the required limit."<<endl
   }
 return choice;
}

Note the above has not been testet..