Lachie
Lachie

Reputation: 105

Error: 'object' was not declared in this scope (C++)

I'm trying to write a linked list of Node objects, where each Node contains: a string - data, and a pointer - next. To manage the list (e.g: add/remove nodes), I have Node objects: head, curr and temp. I'm trying to work out how to link up each node to the previous one when new data is added to the list, but I am having trouble doing so. The error is occuring in Node.cpp when I am trying to link the new node n to the curr nodes next pointer.

LinkedList.cpp:

#include <iostream>
#include <cstdlib>
#include "LinkedList.h"
#include "Node.h"

using namespace std;

LinkedList::LinkedList(value_type setData) {
    head.setData(setData);
    cout << head.getData() << endl;
}

void LinkedList::addNode(value_type addData) {
    Node n;
    n.setData(addData);

    if (head.getData() != "") {
        curr = head;
        while(curr.getNext() != NULL) {
            //Still writing this..
        }
        curr.setNext(n); //Is this correct?
    }
    else {
        head = n;
    }
}

LinkedList.h:

#ifndef LINKEDLIST_H
#define LINKEDLIST_H
#include "Node.h"

class LinkedList {
    public:
        typedef std::string value_type;

        LinkedList();
        LinkedList(value_type setData);
        void addNode(value_type addData);

    private:
        Node head;
        Node curr;
        Node temp;

};

#endif

Node.cpp:

#include <iostream>
#include <cstdlib>
#include "Node.h"

using namespace std;

Node::Node() {
    data = "";
    next = NULL;
}

void Node::setData(value_type setData) {
    data = setData;
}

string Node::getData() { 
    return data;
}

void setNext(Node n) {
    next = n; //'next' was not declared in this scope error.
              //Does this assignment statement even work in this scenario?
}

Node * Node::getNext() {
    return next;
}

Node.h:

#ifndef NODE_H
#define NODE_H

class Node {
    private:    
        typedef std::string value_type;

        value_type data;
        Node* next;

    public:
        Node();
        void setData(value_type setData);
        value_type getData();
        void setNext(Node n);
        Node * getNext();
};

#endif

Any help would be greatly appreciated, thanks guys.

Upvotes: 0

Views: 2171

Answers (2)

cwfighter
cwfighter

Reputation: 502

The function void setNext(Node n); is declared in class Node. So in Node.cpp, you must define the function with void Node::setNext(Node n);. The symbol :: will show the function's scope.

Upvotes: 0

user5151179
user5151179

Reputation: 585

You've got this line:

void setNext(Node n) {

You probably want this instead:

void Node::setNext(Node n) {

Upvotes: 1

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