While writing a code in C error : expected an identifier while defining enum

Question

while coding in C, for the below syntax, I receive an error: expected an identifier, please let me know where am I going wrong ? Thank you.

enum a { 
    false;   // error : expected an identifier
    true;   // // error : expected an identifier
 };

typedef enum a a;

Reason for that is that you use `a` twice in your definition... — arc_lupus, Dec 09 '15 at 12:45
You shouldn't use names that are reserved by the standard libraries. `false` and `true` are already defined by `stdbool.h`, so you shouldn't use those names. — Lundin, Dec 09 '15 at 13:29
@Lundin: But only if `stdbool.h` is `#include`ed. Otherwise they are valid names in C - but not in C++ (maybe he uses a C++ compiler?). OP should provide the context. — too honest for this site, Dec 09 '15 at 13:49

score 3 · Answer 1 · answered Dec 09 '15 at 12:44

3

Use comma after enum constant.

enum a { 
    false,
    true
};

answered Dec 09 '15 at 12:44

artm

score 1 · Answer 2 · edited May 23 '17 at 11:59

1

There should be a comma after false, not a semicolon.

And a comma after true is optional.

You don't even need to Google for it, just search this site. E.g. How to define an enumerated type (enum) in C?

edited May 23 '17 at 11:59

Community

answered Dec 09 '15 at 12:44

Note that trailing comma in an enum is only optional since C99. Earlier, they weren't allowed. It was an inconsistency in the C language which was corrected with C99. – Lundin Dec 09 '15 at 13:28

score 1 · Answer 3 · answered Dec 09 '15 at 12:45

1

typedef enum a { 
    false,
    true
} a;

is a succinct way of doing this. Note the comma after false, and the use of typedef.

I wouldn't recommend using false and true as enumerated names though; especially if you intend to port your code to C++.

answered Dec 09 '15 at 12:45

Bathsheba

3 Answers3