C Language Question

Nilesh Sanyal

What is difference between array of pointer and pointer to an array in respect of multidimensional array? Please explain with simple codes in both cases.

3 Replies

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Vulpes13y ago
The following example may help to make the distinction clear:

#include

int main()
{
int i, j;

/* create 2 dimensional array of ints */
int a[2][2] = {1, 2, 3, 4};

/* create pointer to array */
int *pa = &a[0][0];

/* create 2 dimensional array of pointers to int and initialize it */
int *api[2][2];
api[0][0] = &a[0][0];
api[0][1] = &a[0][1];
api[1][0] = &a[1][0];
api[1][1] = &a[1][1];

/*iterate through int array using pointer*/
for(i = 0; i < 2; i++)
for(j = 0; j < 2; j++)
printf("%d ", *pa++);

printf("\n");

/*iterate through pointer array and dereference the elements */
for(i = 0; i < 2; i++)
for(j = 0; j < 2; j++)
printf("%d ", *api[i][j]);

return 0;
}

As expected the output is:

1 2 3 4
1 2 3 4
13y ago
Hi Nilesh
visit the below links may help your

http://stackoverflow.com/questions/6474104/difference-between-pointer-to-pointer-and-pointer-to-array

http://stackoverflow.com/questions/16692887/difference-between-array-and-pointer
Santhosh Subramaniam13y ago
Hi
Refer this link
http://en.wikibooks.org/wiki/C_Programming/Pointers_and_arrays