CODEWITHSUNDEEP
c++
miechooy
miechooy

Reputation: 3422

C++ error reading character of string

I am trying to add an array to my Object which contains dynamic array

MyCollection.h

    template <typename T>
    MyCollection<T>::MyCollection(int size)
    {
        arraySize = size;
        anArray = new T[size];
    }

    template <typename T>
    MyCollection<T>::MyCollection(MyCollection<T>& coll)
    {
        arraySize = coll.arraySize;
        anArray = new T[arraySize];

        for (int i = 0; i < arraySize; i++)
        {
            SetValue(coll.GetValue(i), i);
        }
    }

    template <typename T>
    MyCollection<T>::MyCollection(T* myArray, int size)
    {
        anArray = myArray;
        arraySize = size;
    }




   template<typename T>
    void MyCollection<T>::AddAll(T pArray[], int size)
    {
        int plusSize = size - 1;
        int arrayIterator = 0;
        arraySize += size;


        for (int i = size; i < arraySize - plusSize; i++)
        {
            anArray[i] = pArray[arrayIterator];
            arrayIterator++;
        }

    }

Main

MyCollection<string> B = MyCollection<string>(new string[3], 3);
    B.SetValue("C", 0);
    B.SetValue("D", 1);
    B.SetValue("E", 2);

string C[3];
    C[0] = "X";
    C[1] = "Y";
    C[2] = "Z";

B.AddAll(C, 3);
    B.Display();

In the AddAll method I have error with acces violation. When I add watch anArray[i] = . Is there any idea why that happens? Is it problem with copy construcotr or so ?

Upvotes: 0

Views: 1555

Answers (1)

vsoftco
vsoftco

Reputation: 56547

In AddAll(), you need to resize the raw array anArray, there is no resizing going on (you just change the numeric value of arraySize, but do not allocate more memory). So you need something like

delete[] anArray; 
// ...
anArray = new T[arraySize];

You may also think whether you want to copy the old elements into the newly allocated array, in which case you first have to reallocate with a temporary pointer, then copy into it, then delete the original anArray, and finally assign the temporary pointer to the original anArray, something like:

// save the old size
int oldSize = arraySize;
arraySize += size;
T* tmp = new T[arraySize];
// copy from anArray into tmp, use oldSize
// for(...){...}
delete[] anArray;
anArray = tmp;

Upvotes: 1

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