为什么我的函数收到的错误是它未在此范围内定义？ 我只是试图调用该函数并让它现在运行

Question

I am simply trying to have the createList function called and run, but I get an error that create list was not defined in this scope. I am not sure what I am doing wrong.

typedef struct state {
  char trans[100];
  bool final;
  struct state *next;
} STATE;

STATE *stu = NULL;

stu = createList(stu, trans, states);

STATE* createList (STATE *stu, char trans, int states) {
    for (int i = states; i > 0; i--) {
        printf("%d", i); /*ccode check*/
    }
    return stu;
}

Answer 1

If this is your C file, then there are two things to note:

1. You must declare the function (ie a prototype) before you can use it.

2. You cannot have executable code on the global level.

Try:

typedef struct state {
  char trans[100];
  bool final;
  struct state *next;
} STATE;

STATE *stu = NULL;

STATE* createList (STATE *stu, char trans, int states) {
    for (int i = states; i > 0; i--) {
        printf("%d", i); /*ccode check*/
    }
    return stu;
}

int main (void)
{
    stu = createList(stu, trans, states);
    return 0;
}

Note that I didn't give a prototype in this example because the complete function is defined before it's used, so the compiler knows all about it.