Pointers

Recall that an int stores a number.
Unlike primative types, pointers store addresses, not values.
For instance, in the following code, x will store the value 5:

int x = 5;

Whereas, in this next code, ptr will store an address in memory:

int *ptr = nullptr;

nullptr means it is not pointing to anything right now, because we havent assigned it any data.
Creating a pointer on the stack:

int x = 5;
int *ptr = nullptr // Points to nothing at the moment
ptr = &x; // Sets the address stored in ptr to the address of x
cout << *ptr // Print the value (5) stored in ptr
ptr = nullptr // Disconnects the pointer

Creating a pointer on the heap:

int *ptr = new int; // Creates a pointer to a new int
*ptr = 5; // Sets the value of ptr to 5
delete ptr; // Deleting does NOT remove data, it just disconnects the stack and heap
ptr = nullptr; // This is optional but makes sure you dont access weird data

Anytime the new keyword is used, something is being created on the stack.

Pointers to arrays

Consider we declare a pointer:

int *arr = new int[5];

The stack contains the pointer’s address itself.
The heap contains the values in the array.
Deleting the pointer (required):

delete [] score;

Multidimentional arrays are important but I think I understand them enough to omit them from here, they are basically the same.
Although, make sure to dealocate in the reverse order that you allocated. So for instance, deallocate the arrays holding the values, then the arrays holding the arrays.

Pointers to classes

If you create a pointer that stores a class, you must use -> instead of . when calling a function.

Example:

Student *s1 = nullptr;
Student s2(/* some parameters */);
s1 = &s2;
s1->somefunc():