Question

i am working on an assignment where i am asked to implement a linked list in c++. so far everything is working great except for when i am creating a new list. in my method create_list(). after i assign content and an id number to my Field and try to call GetNext() i get an error saying: Request for member 'GetNext()' in 'Node' which is a non-class type '*Field'. I’m still new to the C++ syntax and object oriented programming. What am I doing wrong? I thought by using the line Field *Node = new Field(SIZE, EMPTY); that my variable Node would be of class type Field…?

#include <iostream>
#include <ctype.h>

using namespace std;

typedef enum { EMPTY, OCCUPIED } FIELDTYPE;

// Gameboard Size
int SIZE;  

class Field {

private:
int _SquareNum; 
FIELDTYPE _Content; 
Field* _Next;

public: 
// Constructor
Field() { }

// Overload Constructor
Field(int SquareNum, FIELDTYPE Entry) { _SquareNum = SquareNum; _Content = Entry; }

// Get the next node in the linked list
Field* GetNext() { return _Next; }

// Set the next node in the linked list
void SetNext(Field *Next) { _Next = Next; }

// Get the content within the linked list
FIELDTYPE GetContent() { return _Content; }

// Set the content in the linked list
void SetContent(FIELDTYPE Content) { _Content = Content; }

// Get square / location 
int GetLocation() { return _SquareNum; }

// Print the content
void Print() { 

    switch (_Content) {

        case OCCUPIED: 
            cout << "Field " << _SquareNum << ":\tOccupied\n"; 
            break;
        default:
            cout << "Field " << _SquareNum << ":\tEmpty\n";
            break;
    }

} 

}*Gameboard;

here is my create_list() method:

void create_list()
{
int Element; 


cout << "Enter the size of the board: ";
cin >> SIZE; 
for(Element = SIZE; Element > 0; Element--){
    Field *Node = new Field(SIZE, EMPTY);
    Node.GetNext() = Gameboard; // line where the error is 
    Gameboard = Node;
    }
}

Answer 1

No in the declaration

Field *Node = new Field(SIZE, EMPTY);

Node is of type pointer to Field.

The fix is simple if you have a pointer to a class and you want to access a member of that class use ->.

Node->GetNext() = Gameboard;

I think your code has other errors, and I don’t think that even with this ‘fix’ it’s going to work. Probably what you really want is

Node->SetNext(Gameboard);