Code:int main() { int a[] ={ 1,2,3,4,5,6,7}; char c[] = {' a','x','h','o','k'}; printf("%d %d ",&a[0],&a[3]);//prints address with with the diffence of 12 printf("\n%d\t %d ", (&a[3]-&a[0]),(&c[3]-&c[0]));//but how come the diffrence is //3 ?????????????????????
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You should actually be using the %p format specifier to print pointers, and cast the pointers to void* if they are not already of that type.Originally Posted by dpp
Because pointer arithmetic works that way. Add 1 to a pointer and you get a pointer to the next element.
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So many types in your code. Please verify your code prior to a cut-n- paste. Please indent. This is requested so much in these forums. You are missing a dereference operator for your first/second printf() calsl, that is if I understand your intent here.
Are you wanting to subtract the values the index references or the memory addresses; if you are wanting the memory values, see Laserlight's suggestion.
Last edited by slingerland3g; 12-11-2009 at 12:14 PM. Reason: laserlights suggestion
This was a debugging question...I was puzzled with it...
what if i need to print the diffrence in the address.. shud i store the address in a pointer variable and subtract it
Try this, if you are wanting to view the addresses and their spread between each element.
Code:printf ("%p %p ", &a[0], &a[3]); /*Change specifier from %d to %p */ printf ("\n%p\t %p ", (&a[3] - &a[0]), (&c[3] - &c[0])); /*Difference should be 3 */
You just need to multiply the pointer difference by the sizeof the type.
More accurately:
I note that in the original code a multi-character literal was used, but that is probably just a typo error.Code:printf("%p %p\n", (void*)&a[0], (void*)&a[3]); /* Change specifier from %d to %p */ printf("%d %d\n", (&a[3] - &a[0]), (&c[3] - &c[0])); /* Difference should be 3 */
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Ah.. (void*)...yes, thanks!
PS: nice peer review there!
