pointer vs reference

1. pointer can be re-assigned.
2. pointer variable has its own identity: a distinct, visible memory address that can be taken with the unary & operator and a certain amount of space that can be measured with the sizeof operator.
3. it is possible to create a pointer to a pointer, but not a pointer to a reference or reference to reference(will collapse).
4. it is possible to create an array of pointers, but not an array of references.
5. pointer can be assigned nullptr, whereas a reference must be bound to an existing object.
6. pointer needs to be dereferenced with * to access the object it points to, whereas a reference can be used directly. A pointer to a class/struct uses -> to access its members whereas a reference uses a ..
7. const reference and rvalue reference can be bound to temporaries. pointers cannot.

const int &x = int(12); // legal C++
int *y = &int(12); // illegal to take the address of a temporary.