Object reference vs pointer

Pointer

• You think of pointer as just another type like int, char, float, it takes up a constant amount of spaces in memory, and you can assign values to them.
• The value you assign to them is a memory address. You can interpret the memory address pointed by the pointer using the dereferencing operator (*).
• A pointer can be assigned to point a NULL value
• A pointer can be changed to point to any variable of the same type.
• You can do pointer arithmetic, but you cannot with references.

References

• A reference must be initialized when it is declared
• It cannot be NULL
• You can use it by simply using the name. Reference is implemented via pointer, a constant pointer with automatic indirection, the compiler will apply the dereferencing for you automatically.
• Think of references as an alias to existing object in memory.