confusion in basics of linklist

Question

I was going through the linked list and I have confusion. maybe I am mixing the concept or something else. Here is the code of creating the header node.

struct node
{
   int data;
   struct node *link;
};
node *head;
void main()
{
   head = new node;
}

1)The first thing I want to know is how can we write struct node *link; in inside the same node structure? because using first the node structure is created then we can declare pointer of that.
2) node *head; will already declare a memory of size node, then we need to do again head = new node;?

Answer 1

The self referential struct can hold a pointer to itself. Please do not confuse with size of pointer to size of structure. Size of pointer is constant irrespective of data type.

struct node
{
    int data;
    struct node *link;
};

Had it the struct node *link be something else like struct node link, It will not compile just like you think.

regarding why allocation by using the new is required, when we do node *head, it says that head points to memory location of actual node with area for data and link.

It might be useful to read pointer concept again