C++ Resize Dynamic Array

Question

I've been trying to resize this array, and it compiles just fine, but when I run it I get this really long error message.

Here's the code for the function:

void arrayClass_Namespace::arrayClass::resize(int newSize)
{
    std::cout << "\nPlease input a new size for the array: ";
    std::cin >> newSize;

    assert(newSize < MAX_SIZE);

    int *resize_arr = new int[newSize];
    for(int index = 0; index < size; index++)
    {
        resize_arr[index] = arr[index];
    }

    size++;
    arr = resize_arr;
    delete[] resize_arr;
}

Here's the updated code that works perfectly fine now:

void arrayTools_GabriellaRamirez::arrayTools::resize(int newSize)
{
    std::cout << "\nPlease input a new size for the array: ";
    std::cin >> newSize;

    assert(newSize < MAX_SIZE);

    int *resize_arr = new int[newSize];
    for(int index = 0; index < size; index++)
    {
        resize_arr[index] = arr[index];
    }

    for(int index = size; size < newSize; index++)
    {
        size++;
    }

    for(int index = size; size > newSize; index++)
    {
        size--;
    }

    delete [] arr;
    arr = resize_arr;
}

Answer 1

delete[] resize_arr is deleting the new array you made. You need to do

delete[] arr;
arr = resize_arr;

As an aside, you don't check to make sure the new array size is not smaller than used so you could potentially write out of bounds of the new array.

Also I think size++ is not correct.