Questions about Class using Linked List

[luckyvictor]

class LinkedList
{
private:
struct Node {
Item data;
Node* next;
};

Node *HeadList;

public:
LinkedList();
~LinkedList();
void insertItem(Item data);

};

I have written this piece of code, and I have several questions.

1st.　Mａｙ　Ｉ　ｕｓｅ　ｔｙｐｅｄｅｆ　ｔｏ　ｒｅｐｌａｃｅ　Ｎｏｄｅ*，　ｓｕｃｈ　ａｓ　typedef Node* NodePtr;　ｂｅｃａｕｓｅ　Ｉ　had error no matter where I put this, I don understand why.

2nd. Ｔｈｉｓ　ｉｓ　ｍｙ　ｃｏｄｅ　ｆｏｒ　ｔｈｅ　ｃｏｎｓｔｒｕｃｔｏｒ，　ｗｈｙ　ｄo I not have to include "Node* HeadList = new Node"????
LinkedList::LinkedList() {
//Node* HeadList = new Node;
HeadList = NULL;
}

3rd. In my insertItem, I have to declare several Nodes, and I don understand why I can't declare them and then assign their value? e.g I have to write "Node* newPtr = new Node", but I can't first write Node* newPtr, then "newPtr = new Node", and further more, why do I have to write "Node* newPtr = new Node" in this case but not for the constructor?

I appreciate for all the repies!!! I really need helps!!

[jsmith]

1) Yes.

2) You already declared HeadList as a member of the class, therefore you
could just write HeadList = new Node; in the constructor. But writing
Node* HeadList = new Node; is trying to declare a local variable named
HeadList.

3) You should be able to.

NodePtr* newPtr;
newPtr = new Node;

should work. Did you forget a semicolon?