Pointer question

[doddolfur]

I have a struct for a linked list, if I declare it like this

struct node
	{
	const char *snake;
	node *tail;

	}*p;

am i right that p is now a pointer to a struct node?
What is the difference between this and just doing
node *p;
p = new node;

since I have to allocate the p pointer anyway?

[BHX]

I believe so. That should be the same as:

struct node
{
      const char *snake;
      node *tail;
};

node *p;
p = new node;

Oh, I misread that.
p = new node; is doing dynamic memory allocation but not experienced enough to say 100% if there is a difference between the two.

[Veltas]

Really? I would have expected it to declare the pointer, but not fill it!

[vlad from moscow]

The difference is that in the first case your pointer does not initialized while in the second case a memory was allocated for an object of type node and its address was assigned to the pointer.
To make the first case to be similar the second case you can write

struct node
{
	const char *snake;
	node *tail;

} *p = new node;

[BHX]

Yeah, I had misread the question. I thought he was asking if doing

struct node
{
      const char *snake;
      node *tail;
}p; 

was the same as doing

 
struct node
{
      const char *snake;
      node *tail;
}

node *p; 
p = new node;  // thought his was just a example of allocating when I first read it 

Though, most tutorials and books I've read have said to refrain from doing

struct node
{
}*p, *jumper;

class Person
{
} *varches; 

Instead they say to do this

node *p;
node *jumper;
Person *varches;

Though they never really explain why this is a bad thing to do, but I just keep doing the method they recommended.

[doddolfur]

ok I think I understand now. So with the first pointer:

struct node
	{
	const char *snake;
	node *tail;

	}*p;

I can use *p to iterate through what is in the struct etc but I can't make it do things like adding a new node to the struct or assigning any new elements to the struct without dynamic allocation?

thanks for your answers guys