In C++ What are the differences between a pointer variable and a reference variable?


When a variable is declared as reference, it becomes an alternative name for an existing variable.


Type &newname = existing name;


Type &pointer;
pointer = variable name;


Pointers are used to store the address of variable.


Type *pointer;


Type *pointer;
pointer = variable name;

The main differences between references and pointers are -

  • References are used to refer an existing variable in another name whereas pointers are used to store address of variable.

  • References cannot have a null value assigned but pointer can.

  • A reference variable can be referenced by pass by value whereas a pointer can be referenced but pass by reference.

  • A reference must be initialized on declaration while it is not necessary in case of pointer.

  • A reference shares the same memory address with the original variable but also takes up some space on the stack whereas a pointer has its own memory address and size on the stack.