Return value of "==" operator in C

Question

Can I assume that in C, the "==" operator will always evaluate to 1 if the two values are equal or it can evaluate to other "true" values?

struct ss {     int id; };  struct os {     int sid;     int state; };  int count(struct ss *s, int state) {     int num = 0;     // foreach o (of type os*) in a hash table         num += o->state == state && (s ? o->sid == s->id : 1);      return num; } 

So o->sid == s->id will return always 1 or 0, or it can return other values?

Answer 1

Can I assume that in C, the "==" operator will always evaluate to 1 if the two values are equal or it can evaluate to other "true" values?

Yes, and so does != > < >= <= all the relational operator.

C11(ISO/IEC 9899:201x) §6.5.8 Relational operators

Each of the operators < (less than), > (greater than), <= (less than or equal to), and >= (greater than or equal to) shall yield 1 if the specified relation is true and 0 if it is false.107) The result has type int.