Why does calling 'delete' in a specific way on a dynamic array not work?

Question

I'm wondering why this code doesn't work:

void KeyValueList::Release()
{
//(m_ppKeyValueList is a dynamic array of pointers to objects on the heap)
    if (m_ppKeyValueList) {
        for (int i = 0; i < m_iCapacity; ++i) {
            if (m_ppKeyValueList[i]) {
                delete m_ppKeyValueList[i];
            }
        }
        /*delete[] m_ppKeyValueList;*/
        for (int i = 0; i < m_iCapacity; ++i) {
            delete (m_ppKeyValueList + i);
        }
    }
}

Why can't we iterate the dynamic array and delete it in this way?

Answer 1

A dynamic array is more than just a sequence of elements. It contains information about the array size as well. Moreover, there is just one chunk of memory known to the allocator. So just like with any dynamic memory, you can only free what you allocated, not smaller subsets of it.

That's why the language requires that you only invoke delete[] on a pointer obtained from a new[] expression, and that that is the only way to deallocate that memory.