Pointers

Question

In the code inserted below :
What is the meaning of ptr+i and why don’t we use ptr(i) ?
int a[5] = {22, 33, 44, 55, 66};
int *ptr = NULL;
int i;

ptr = a;
for (i = 0; i < 5; i++) {
printf("%d ", *(ptr + i));

Answer 1

https://www.learncpp.com/cpp-tutorial/6-8a-pointer-arithmetic-and-array-indexing/#:~:text=The%20C%2B%2B%20language%20allows%20you,the%20previous%20integer%20before%20ptr%20.
This is called as pointers arithmetic, check this link, there is everything what you neeed

Answer 2

>> why don’t we use ptr(i) ?
ptr(i) is an error, because ptr is not a function taking some argument; but ptr[i] is effectively equivalent to *(ptr+i) and can be used in place of that.

Answer 3

Bilbo thanks