Access Item in Nested Structure in C

Question

I try to access \"next\" in another structure, but failed although i have tried many ways.

Here is the nested structure:

struct list_head {
    struct l         


        

Answer 1

In your definition, you are defining list to be an object as below

typedef struct {
    char *key;
    char *value;
    struct list_head list; // This is an object
}dict_entry;

Hence, you will de-reference next through the . operator as d->list.next. The first level of de-referencing i.e. d->list requires -> operator as d is defined to be a pointer. For next, since list is an object and not a pointer, you would have to use . operator.

Answer 2

list is not declared as a pointer, so you don't use the -> operator to get its members, you use the . operator:

while (d->list.next != NULL) {
}

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A different fix:

typedef struct {
  char *key;
  char *value;
  struct list_head *list;
}dict_entry;

This way, your original code attempting to refer to next would compile.