help please in stack

[madjas]

im trying to add more memory space to this stack code using this:
temp = new(nothrow) StackElement[myCapacity + 10];
for (int i = 0; i < myCapacity; i++)
temp[i] = myArray[i];
delete [] myArray;
myArray = temp;

and this is my code:

Stack::Stack(int numElements)
{
   assert (numElements > 0);  // check precondition
   myCapacity = numElements;  // set stack capacity
                              // allocate array of this capacity
   myArray = new(nothrow) StackElement[myCapacity];
   if (myArray != 0)          // memory available
      myTop = -1;
   else
   {
      cerr << "Inadequate memory to allocate stack \n"
              " -- terminating execution\n";
      exit(1);
   }                          // or assert(myArray != 0);
}

//--- Definition of Stack copy constructor
Stack::Stack(const Stack & original)
: myCapacity(original.myCapacity), myTop(original.myTop)
{
   //--- Get new array for copy
   myArray = new(nothrow) StackElement[myCapacity];  
   if (myArray != 0)                 // check if memory available
      // copy original's array member into this new array
      for (int pos = 0; pos <= myTop; pos++) 
         myArray[pos] = original.myArray[pos];
   else
   {
      cerr << "*Inadequate memory to allocate stack ***\n";
      exit(1);
   }
}

//--- Definition of Stack destructor
Stack::~Stack()
{ 
   delete [] myArray;
}

//--- Definition of assignment operator
const Stack & Stack::operator=(const Stack & rightHandSide)
{
   if (this != &rightHandSide)                // check that not st = st
   {
      //-- Allocate a new array if necessary
      if (myCapacity != rightHandSide.myCapacity) 
      {
         delete[] myArray;                    // destroy previous array

         myCapacity = rightHandSide.myCapacity;  // copy myCapacity 
         myArray = new StackElement[myCapacity]; 
         if (myArray == 0)                    // check if memory available
         {
            cerr << "*** Inadequate memory ***\n";
					
            exit(1);
         }
        }
		
      myTop = rightHandSide.myTop;            // copy myTop member
      for (int pos = 0; pos <= myTop; pos++)  // copy stack elements
         myArray[pos] = rightHandSide.myArray[pos];

   }
   return *this;
}


//--- Definition of empty()
bool Stack::empty() const
{ 
   return (myTop == -1); 
}

//--- Definition of push()
void Stack::push(const StackElement & value)
{
   if (myTop < myCapacity - 1) //Preserve stack invariant
   { 
      ++myTop;
      myArray[myTop] = value;
   }
   else
   {
      cerr << "*** Stack full -- can't add new value ***\n"
              "Must increase the stack's capacity.\n";
      exit(1);
   }
}

//--- Definition of display()
void Stack::display(ostream & out) const
{
   for (int i = myTop; i >= 0; i--) 
      out << myArray[i] << endl;
}

//--- Definition of top()
StackElement Stack::top() const
{
   if ( !empty() ) 
      return (myArray[myTop]);
   else
   {
      cerr << "*** Stack is empty -- returning garbage value ***\n";
      StackElement garbage;
      return garbage;
   }
}

//--- Definition of pop()
void Stack::pop()
{
   if ( !empty() )
      myTop--;
   else
      cerr << "*** Stack is empty -- can't remove a value ***\n";
}



void print(Stack st)
{ 
	st.display(cout);
}

int main()
{
   int cap;
   cout << "Enter stack capacity: ";
   cin >> cap;

   Stack s(cap);
   cout << "Stack created.  Empty? " << boolalpha << s.empty() << endl;

   cout << "How many elements to add to the stack? ";
   int numItems;
   cin >> numItems;
   for (int i = 1; i <= numItems; i++) 
      s.push(100*i);
   cout << "Stack empty? " << s.empty() << endl;

   cout << "Contents of stack s (via  print):\n";
   print(s); cout << endl;
   cout << "Check that the stack wasn't modified by print:\n";
   s.display(cout); cout << endl;

   Stack t, u;
   t = u = s;
   cout << "Contents of stacks t and u after t = u = s (via  print):\n";
   cout << "u:\n"; print(u); cout << endl;
   cout << "t:\n"; print(t); cout << endl;

   cout << "Top value in t: " << t.top() << endl;

   while (!t.empty())
   {
     cout << "Popping t:  " << t.top() << endl;
     t.pop();
   }
   cout << "Stack t empty? " << t.empty() << endl;
   cout << "\nNow try to retrieve top value from t." << endl;
   cout << "Top value in t: " << t.top() << endl;
   cout << "\nTrying to pop t: " << endl;
   t.pop();
}

should i use template???????????

[agile]

First of all get rid of exit(1) calls, it's not a good idea. Use bool/int return value (or argument in constructor) to indicate success or failure or throw an exception.

> should i use template?
If you want to use Stack class with types other that int then use templates. You can have simpler implementation of Stack class by deriving from (protected/private derivation) or aggregating std::vector/std::list.

Good luck!

[madjas]

ok i will delete exit and use bool. about this code should i implement another function in order to use this code.

temp = new(nothrow) StackElement[myCapacity + 10];
for (int i = 0; i < myCapacity; i++)
temp[i] = myArray[i];
delete [] myArray;
myArray = temp;

[agile]

Yes, you need another member function.
But again, if you are not writing this code for learning purposes, then better use standard containers. They can do it all for you.

[madjas]

tanks.... that's for learning purposes!!!! im just trying to swap to another memory when one is full