Function prototype in C

Question

Let us suppose the following program:

#include <stdlib.h>
int main()
{
  int a,b,;
  scanf("%d",&a);
  scanf("%d",&b);
  c = func(a,b);
  printf("%d",c);
  return 0;
}

int func(int a, int b)
{
  return a+b;
}

Now, let us suppose the following options for defining a prototype for the function "func".

Option 1:

int func(int a, int b);

Option 2:

int func(int , int);

What are the differences between option 1 and 2? They have exactly the same effects?

https://stackoverflow.com/questions/8174886/put-name-of-parameters-in-c-function-prototypes — pzaenger, Oct 06 '18 at 20:57
The prototype doesn't need to mention the names, only the types. — Weather Vane, Oct 06 '18 at 20:57
Possible duplicate of [Put name of parameters in C function prototypes?](https://stackoverflow.com/questions/8174886/put-name-of-parameters-in-c-function-prototypes) — kiran Biradar, Oct 06 '18 at 21:00
They're the same. However `int func(int parcel1, int parcel2);` *(you can use `int func(int a, int b) { /*...*/ }` for the definition)* is more descriptive. — pmg, Oct 06 '18 at 21:03

score 3 · Answer 1 · answered Oct 06 '18 at 20:58

3

1 and 2 are exactly the same. The C compiler allows you to put in parameter names, but they are arbitrary: subject to their being legal names (for example, they can't be keywords, or contain a leading double underscore), the compiler will ignore them.

answered Oct 06 '18 at 20:58

Bathsheba

231,907
34
361
483

score 1 · Answer 2 · answered Oct 06 '18 at 20:58

1

The two options are the same, but the first one gives more information on what the parameters are (for more advanced functions).

clang-tidy has a rule that warns against writing option 2.

answered Oct 06 '18 at 20:58

Matthieu Brucher

21,634
7
38
62

Function prototype in C

2 Answers2