Question

So I’m new to C and I’m trying to implement a cart via a linked list as follows.

typedef struct {
  char *name;
  int count;
  struct node *next;
} item;


struct cart {
  item *curr, *head;
  head = NULL;

};

When I go to compile though, I get the following errors:

ceasarb@ampersand:~> clang shopper.c 
shopper.c:14:3: error: type name requires a specifier or qualifier
  head = NULL;
  ^
shopper.c:14:3: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
  head = NULL;
  ^~~~
shopper.c:14:3: error: duplicate member 'head'
shopper.c:13:16: note: previous declaration is here
  item *curr, *head;
               ^
shopper.c:14:7: error: expected ';' at end of declaration list
  head = NULL;
      ^
      ;

I’m guessing the root of the problem is

 type name requires a specifier or qualifier

But I can’t figure out what that means.

Answer 1

Assignments are not allowed within a struct definition, this is your problem.

In order to initialise head to NULL, you should declare an instance of that struct and use the appropriate initialiser:

struct cart {
  item *curr, *head;
} sample_cart = {
  NULL, NULL,
};

The head and curr fields of sample_cart are now both NULL.