Question

Let’s say I have 2 2-dimensional arrays:

int a1[][2] = { {1,2}, {3,4}, {5,6} };
int a2[][2] = { {7,8}, {9,0}, {1,1} };

and a pointer:

int *a;

The pointer will point to one of the arrays and at some point point to the other (back and forth). After each reassignment of the pointer I want to read from the array, what is the easiest way to do that?

I can achieve what I want using the following way:

a = (int *)a1;
printf("D: %d\n", (int)(*a)+(x*2)+(y)));
a = (int *)a2;
printf("D: %d\n", (int)(*a)+(x*2)+(y)));

Output (assuming x = 0 and y = 1):

D: 2
D: 8

Is there another easier way to access the arrays I.e. by using the standard [] operator? If not, then how would you make this more “beautiful”… would you create a macro or a function or what would be the preferred way of doing it?

Answer 1

You can make use of [] if you always have pairs and turn the pointer to

int (*a)[2];

This should make it possible to write

a = a1;
printf("D: %d\n", a[x][y]);