Code Capsules

Listing 9 Illustrates a pointer to a 2-d array within a 3-d array

/* array9.c:    Uses a pointer to a 2-d array */

#include <stdio.h>

main()
{
   int a[][3][4] = {{{0,1,2,3},{4,5,6,7},{8,9,0,1}},
                 {{2,3,4,5},{6,7,8,9},{0,1,2,3}}};
   int (*p)[3][4] = a;
   int i, j, k;
   size_t ntables = sizeof a / sizeof a[0];
   size_t nrows   = sizeof a[0] / sizeof a[0][0];
   size_t ncols   = sizeof a[0][0] / sizeof a[0][0][0];
    
   printf("sizeof(*p) == %u\n",sizeof(*p));
   printf("sizeof(a[0][0]) == %u\n",sizeof(a[0][0]));
   for (i = 0; i < ntables; ++i)
   {
      for (j = 0; j < nrows; ++j)
      {
         for (k = 0; k < ncols; ++k)
            printf("%d ",p[i][j][k]);
         putchar('\n');
      }
      putchar('\n');
   }
   return 0;
}

/* Output
sizeof(*p) == 24
sizeof(a[0][0]) == 8
0 1 2 3
4 5 6 7
8 9 0 1

2 3 4 5
6 7 8 9
0 1 2 3

*/

/* End of File */