References in C

Question

Possible Duplicate:
Passing pointer argument by reference under C?

Are reference variables a C++ concept? Are they available in C? If available in C, why is my code giving a compilation error?

#include <stdio.h>
#include <stdlib.h>

int main()
{
  int a = 10;
  int b = 20;
  int &c = a;
  int &d = b;
  return 0;
}

Output:

bash-3.2$ gcc test.c
test.c: In function `main':
test.c:12: error: parse error before '&' token

Why?

Answer 1

C does not have references as a type. The '&' in C is used to get the address of a variable only. It cannot be used the way you are trying to use it in C.

Answer 2

1. It's a concept available on C++ (but not exclusively)
2. No, it is not available in standard C.
3. See 1 and 2. See *1 and *2.

Answer 3

You can't use this to declare variables:

int &c = a;

The operator & is used to get the memory address of a variable. So, you could write for example:

int a = 10;
int *c;
c = &a;

Answer 4

Pass by reference isn't available in C, use simple pointers instead.

Answer 5

References are a C++ concept only. In C you are restricted to using only pointers.

Answer 6

It's been awhile but it looks like you are trying to assign the address of c to the value of a.

Correction: value of a to the address of c. (Thanks Chinmay Kanchi for pointing that out.)

Answer 7

No, reference is C++ only.