Thread: Linked List Problem

Hello there! I am reacquainting myself with C/C++ after a few years of not practicing it. I am practicing Linked Lists but I cannot succeed in compiling a code. Take a look:

Base Class Declaration

Code:

class Base
{
    char *pstrName;              //STORE NAME
    char *pstrId;                //STORE ID
    static int iCount;           //KEEP TRACK OF THE CLASSES CREATED
    
    public:
        //CONSTRUCTOR(S) AND DESTRUCTORS
        Base();
        Base(char *Name, char *Id);
        virtual ~Base();
        
        //ACCESSOR METHODS
        char *ReturnName(); 
        char *ReturnId();
        int	  ReturnCount();

		//LINKED LIST
		class Base *next;
    };

This is the code I am trying to create a linked list:

Code:

Base *LinkedBase1 = new Base();	

Base *pHead = (Base*)0;

pHead->next = LinkedBase1;

Although when I attempt to compile the code it gives me an error....I can't figure it out...

Code:

------ Build started: Project: Classes, Configuration: Debug Win32 ------
1>Compiling...
1>main.cpp
1>c:\documents and settings\obliviouse\my documents\visual studio 2005\projects\classes\classes\main.cpp(15) : error C2143: syntax error : missing ';' before '->'
1>c:\documents and settings\obliviouse\my documents\visual studio 2005\projects\classes\classes\main.cpp(15) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\documents and settings\obliviouse\my documents\visual studio 2005\projects\classes\classes\main.cpp(15) : error C2040: 'pHead' : 'int' differs in levels of indirection from 'Base *'

Can someone help me? Thanks in Advance...

The reason for the compiler errors might be due to superfluous class keyword here:

Code:

		//LINKED LIST
		class Base *next;

As to the rest:

Code:

Base *pHead = (Base*)0;

pHead->next = LinkedBase1;

The cast should be unnecessary. Any type of pointer should be able to be a NULL pointer. And on the next line you seem to be dereferencing a NULL pointer to set it's next member. However, pHead doesn't point to anything, so there is no next member.

As to the design with classes, normally you'd separate a Node class/struct and a LinkedList class:

Code:

struct Node
{
     data
     Node* next;
};

class LinkedList
{
     Node* head;
     unsigned Count; // if you want
  
     public methods
};

Not making this distinction leads to this in your code:

Code:

static int iCount;           //KEEP TRACK OF THE CLASSES CREATED

If I understand the purpose of iCount (NodeCount?) then you'd only be able to use only one linked list in a program (because of static).