Arithmetic - Operations

++ / --

Incrementing or decrementing a pointer moves it to the next or previous memory location of the same data type. This is very useful when we have an array and we set the pointer to point to the first element, with each increment we move one element to the right

int list[] = {1, 2, 3, 4, 5};
int *ptr = &list[0];
cout << *ptr << " ";
ptr++;
cout << *ptr << " ";
ptr--;
cout << *ptr;

Output:
1 2 1

As you can see when we increment/decrement the pointer we move to the next memory location from the same type, in this case to the next/previous element in the array

+= / -=

Adding or subtracting a larger number than 1, can help us move quicker and more elements at a time

int list[] = {1, 2, 3, 4, 5};
int *ptr = &list[0];
cout << *ptr << " ";
ptr += 4;
cout << *ptr << " ";
ptr -= 2;
cout << *ptr;

Output:
1 5 3

n = p2 - p1

The final useful operation that we can do with pointers is to calculate how many elements there are in between them. We can do that by calculating their difference

int list[] = {1, 2, 3, 4, 5};
int *ptr = &list[0];
int *ptr2 = &list[4];
cout << "Between " << *ptr << " and " << *ptr2
 << " there's " << ptr2-ptr << " elements";

Output:
Between 1 and 5 there's 4 elements

We can use these 3 techniques to perform many useful operations with pointers and solve problems in our regular tasks