initialize two dimensional array of pointer elements using memset

Question

Hi,

I have a these structures definitions

typedef struct my_s {
   int x;
   int y;
} my_T;

typedef struct your_s {
    my_T * x;
} your_T;

your_T array[MAX_COL][MAX_ROW];

To initialize the array's pointer to NULL, can I do:

memset (array, 0, sizeof(array))

this does not look right to me,,, appreciate some advise.

Thanks

Answer 1

easiest is

your_T array[MAX_COL][MAX_ROW] = {{{0}}};

Answer 2

typedef struct my_s {
   int x;
   int y;
} my_T;

typedef struct your_s {
    my_T * x;
} your_T;

your_T array[MAX_COL][MAX_ROW];

You cannot initialize the pointers of your_T to null using memset, because it is not specified that a null pointer has its bit pattern all consisting of null bits. But you can create your array like this:

your_T array[MAX_COL][MAX_ROW] = {{}};

The elements will be default initialized, which means for a pointer that the pointer will contain a null pointer value. If your array is global, you don't even have to care. That will happen by default then.