In this article we will explain moving the pointer through an array. It's simple but sometimes confusing.
So try these simple examples in your unmanaged C++ project.
Creating an array and assigning a pointer to it
int arr[4]; int *ptr = arr; //[*][ ][ ][ ] Points at the first element of the array
When using pointers and arrays, we don't need to use ampersand (&) to assign the address of the array to the pointer. It returns the address of the first array element. But if we want to point at other element (not the first) we must use an ampersand.
Then we assign a value to the first element
*ptr = 2; //1st
Moving the pointer two places forward (his address will increase by the size of integer which is 4 bytes, in this case 2x4), now the pointer points at the third element, and we assign a value to it (6)
ptr += 2; //[ ][ ][*][ ] *ptr = 6; //3rd
Other way to point to an element, the way with ampersand. We now point at the last element, the fourth, and assigning a value to it (8)
ptr=&arr[3]; //[ ][ ][ ][*] *ptr=8; //4th
Not moving the pointer but pointing two places left from the pointer, and then assigning a value
*(ptr - 2) = 4; //2nd
Print the value which ptr points on
cout << *ptr << endl;
It will be printed "8", that shows that the pointer points to the last element.
Now print the array
for(int i = 0 ;i < 4 ;i++) cout << arr[i] << endl;
Printed values: 2, 4, 6, 8.
Let's see how to print using the pointer without moving it, but first, make the pointer point on the first element
ptr = arr;
then
for(int i = 0 ;i < 4 ;i++) cout << *(ptr + i) << endl;
or printing by moving the pointer
for(int i = 0 ;i < 4 ;i++) cout << *ptr++ << endl;
