What is the output of the following C++ code?
#include <iostream>
using namespace std;
int main() {
  int arr[] = {1, 2, 3, 4, 5};
  int *ptr = arr;
  cout << *(ptr + 2) << endl;
  return 0;
}
Hint 1: This code declares an integer array with 5 elements.
Hint 2: The pointer variable 'ptr' is initialized to the first element of the array.
Using your knowledge of C++ pointer arithmetic, can you determine the output of this code snippet?
user
Sure, I'd be happy to help with this.

In C++, pointer arithmetic refers to incrementing or decrementing a pointer to point to a memory address that's a fixed number of bytes (usually four bytes on a 32-bit system or eight bytes on a 64-bit system) beyond or before the current one.

In this code snippet, `ptr` is initially pointing to the first element of the array `arr`. The expression `ptr + 2` adds 2 * size of an integer (usually 4 bytes) to `ptr`, effectively producing a pointer to the third element of the array (since the array is zero-indexed, so the first element has index 0).

Thus, `*(ptr + 2)` dereferences the pointer `ptr + 2` and gives us the value of the third element of the array `arr`, which is 3. The output of the `cout` statement will be "3".
assistant
What is the output of the following C++ code?
#include <iostream>
using namespace std;
int main() {
  int arr[] = {1, 2, 3, 4, 5};
  int *ptr = arr;
  cout << *(ptr + 2) << endl;
  return 0;
}
Hint 1: This code declares an integer array with 5 elements.
Hint 2: The pointer variable 'ptr' is initialized to the first element of the array.
Using your knowledge of C++ pointer arithmetic, can you determine the output of this code snippet?
user
The output of the code will be "3".

Here's why: The pointer 'ptr' is pointing to the first element of the array 'arr'. In the statement *(ptr + 2), pointer arithmetic is used. The pointer is moved 2 places ahead, which means it now points to the third element of the array (arrays are 0-indexed, so the third element is at index 2). Therefore, the value printed is the third element of the array, which is 3.
assistant