Question

I understand the overall meaning of pointers and references(or at least I think i do), I also understand that when I use new I am dynamically allocating memory.

My question is the following:

If i were to use cout << &p, it would display the ‘virtual memory location’ of p. Is there a way in which I could manipulate this ‘virtual memory location?’

For example, the following code shows an array of ints.

If I wanted to show the value of p[1] and I knew the ‘virtual memory location’ of p, could I somehow do ‘&p + 1‘ and obtain the value of p[1] with cout << *p, which will now point to the second element in the array?

int *p; p = new int[3];  p[0] = 13; p[1] = 54; p[2] = 42; 

Answer 1

Sure, you can manipulate the pointer to access the different elements in the array, but you will need to manipulate the content of the pointer (i.e. the address of what p is pointing to), rather than the address of the pointer itself.

int *p = new int[3]; p[0] = 13; p[1] = 54; p[2] = 42;  cout << *p << ' ' << *(p+1) << ' ' << *(p+2); 

Each addition (or subtraction) mean the subsequent (prior) element in the array. If p points to a 4 byte variable (e.g. int on typical 32-bits PCs) at address say 12345, p+1 will point to 12349, and not 12346. Note you want to change the value of what p contains before dereferencing it to access what it points to.