I have an array of pointers. How to correctly assign a value to the locations each element of the array points to?

Question

I have this code declaring an array of pointers and assigning value of 5 to the location that the first pointer in the array points to:

int *p[10];
*p[0]=5;

However, this is showing an EXC_BAD_ACCESS error. I tried

int **p = new int *[10];
*p[0]=5;

But this is giving the same error. How do I assign a value to the location pointed by an element of my array of pointers? Thank you.

Answer 1

Before dereferencing the first pointer in the array, you need to initialize it to point to a valid memory location. For example:

int *p[10];
p[0] = new int;
*p[0] = 5;

Note that manual memory allocation at such level is almost certainly not what you want to use , except as a learning exercise, or as part of implementation of a larger structure. If you in fact want to an array of 10 integers, and access parts of it through a pointer, you can do it like this:

int array[10];             // allocate room for ten integers
array[0] = 5;              // initialize the first one
int *first = &array[0];    // get a pointer to the first one
assert(*first == 5);       // work with the pointer

If you do need an array of pointers, look into std::unique_ptr and std::shared_ptr to make sure they do not leak data in case of exceptions, early returns or forgotten delete .