C++ linked list notation, what is the difference?

Question

I just want to know if there is and difference between these two notations:

First example:

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

    void insert(node* list){
      node* n,* last;
      last = list;
      while(last)
         last = last -> next;
      n = new node;
      last = n;
      n -> next = NULL;
      cin >> n -> data;
   }

    int main(){
      node* list = new node;
      list -> next = NULL;
      insert(list);
      return 0;
    }

Second example:

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

    void insert(node* list){
      node* n,* last;
      last = list -> next;
      while(last)
         last = last -> next;
      n = new node;
      last = n;
      n -> next = NULL;
      cin >> n -> data;
   }

    int main(){
      node* list = new node;
      list -> next = NULL;
      insert(list);
      return 0;
    }

So I wonder if there is difference between notation lie: in first example:

last = list;

and in second example

last = lista -> next;

And what does node* list do/represent in void insert(node* list){} Is that just a pointer to whatever list, a pointer that points to the list in the main, or what?

Answer 1

Your above explanation stands correct but let me also add one more point, Suppose your

list = NULL;

void insert(node* list){
  node* n,* last;
  last = list -> next;
  while(last)
     last = last -> next;
  n = new node;
  last = n;
  n -> next = NULL;
  cin >> n -> data;

}

Then in the above case you are trying to access list->next which is next of 'NULL' thus it will give you runtime error because you cant access next of nullptr as it is not defined.