What is the difference between a reference variable and a const pointer variable?

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Difference between pointer variable and reference variable in C++

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Is a reference variable just another name of const pointer variable? If they are different what is the difference between a variable declared as a reference variable and a variable declared as a const pointer variable?

Unless you really meant to ask the difference between a pointer and a const pointer this is a duplicate of the question that you linked to. — CB Bailey, Dec 02 '10 at 07:42
This has already been answered in the same question you are referring to. From the first answer, all points hold besides the *can be reassigned*. Possible duplicate of [Difference between pointer variable and reference variable in C++](http://stackoverflow.com/questions/57483/difference-between-pointer-variable-and-reference-variable-in-c) — David Rodríguez - dribeas, Dec 02 '10 at 08:45

score 3 · Answer 1 · answered Dec 02 '10 at 07:16

3

Just for fun:) A reference can not be NULL but a const pointer can be.

answered Dec 02 '10 at 07:16

Chubsdad

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@Chusbad: first reaction too :p – Matthieu M. Dec 02 '10 at 07:46

score 1 · Accepted Answer · answered Dec 02 '10 at 09:26

1

OK. The problem is that there is no such thing like reference variable. Reference is not a variable at all. It is not an object. It actually has no size at all. It is just alternative name of the original object.

Check this:

struct A
{
   int i[5];
};

int main()
{
   std::cout << (sizeof(A&) == sizeof(A)) << std::endl;
   std::cout << (typeid(A&) == typeid(A)) << std::endl;
   return 0;
}

A& has the same size as A
A& has the same type as A

answered Dec 02 '10 at 09:26

Stas

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Correct for C++03, but [C++0x introduces the notion of reference variables](http://stackoverflow.com/questions/2908834/). – fredoverflow Dec 02 '10 at 11:51

score 0 · Answer 3 · answered Dec 02 '10 at 07:16

Is a reference variable just another name of const pointer variable?

No.

If they are different what is the difference between a variable declared as a reference variable and a variable declared as a const pointer variable?

They are completely different things, and there is not enough room to explain everything you need to know here. Read this. Actually, read the entire FAQ. You'll learn a lot.

What is the difference between a reference variable and a const pointer variable?

3 Answers3