passing pointers to nested functions

Question

I am having problems passing a pointer to a pointer(struct) through a nested function to have memory allocated or reallocated for it. I understand that when passing to a function it is passed by value, and thus only can be edited locally, but am unclear syntactically how to pass it. Important code snippets below:

struct courseData{
                    char name[25];   
                    int id;          
                  };

void menuSwitch(int* courseNum, struct courseData** course);
void addCourse(int* courseNum, struct courseData** course);

int main(){

     struct courseData* course = NULL;  
     int courseNum = 0;

     menuSwitch(courseNum, &course); //Edited from original post.

     return 0;
}

void menuSwitch(int* courseNum, struct courseData** course){

     addCourse(&courseNum, course)
}

menuSwitch is actually a case switch, which calls function addCourse when the menu item is selected.

void addCourse(int* courseNum, struct courseData** course){

      if(*courseNum == 0)
                    *course = (struct courseData*) malloc(sizeof(struct courseData));
            else
                    *course = (struct courseData*) realloc(*course, (*courseNum + 1)*sizeof(struct courseData));

      *courseNum = *courseNum + 1; //Increments course count by 1

      ------code continues------
}

After correcting original problem, compiling results in the following errors/warnings from gcc

main.c: In function ‘main’:
main.c:27:3: warning: passing argument 2 of ‘menuSwitch’ from incompatible pointer type [enabled by default]
header.h:24:6: note: expected ‘struct courseData *’ but argument is of type ‘struct courseData **’
func.c:60:6: error: conflicting types for ‘menuSwitch’
header.h:24:6: note: previous declaration of ‘menuSwitch’ was here
func.c: In function ‘menuSwitch’:
func.c:64:3: warning: passing argument 2 of ‘addCourse’ from incompatible pointer type [enabled by default]
header.h:26:6: note: expected ‘struct courseData *’ but argument is of type ‘struct courseData **’

Thank you for your help, and pardon if this is inappropriate use of the edit ability.

Answer 1

Everything is fine except one line. In void menuSwitch(int* courseNum, struct courseData** course) change

addCourse(&courseNum, course)

to

addCourse(courseNum, course);

Answer 2

You were doing fine until you got to menuSwitch. That function receives courseNum, which is a pointer to int. It should then pass that same pointer addCourse just as it does with course. However, you pass the address of courseNum instead. So instead of passing an int * you're passing the address of a pointer to int *, or an int **. The call to addCourse should simply be this:

addCourse(courseNum, course);