Singly Linked List

[matapexxxX]

Hi I need to make a singly linked list that displays in order the input from the user and displays NULL is the input is o.
While I have most of this done, everytime I run it displays only the first node. It's like the node aren't connected, but from here I don't know how to do it.

  #include <iostream>
using namespace std;

class Node
{
public:
	int  m_data;
	Node *m_next;
};

Node* getListFromUser()
{
	int data;
	Node *head;
	Node *newnode;
	Node *current;

    head = NULL;
	newnode = new Node;
	cout << "Enter numbers, press 0 to stop" << endl;
	cin >> data;
	newnode->m_data = data;


	do
	{
	    	if (data == 0)
		{
		    cout << "NULL" << endl;
		    return 0;
		}
		
		if (head == NULL)
		{
			head = newnode;
			head->m_next = NULL;
		}
		else
		{
		    cout << head->m_data << endl; //To help me debug 
		    
			current = head;
			while (current != NULL)
			{
				current = current->m_next;
			}
			current = newnode;
			current->m_next = NULL;
		}
			cout << "head's next" << head->m_next << endl; //To help me debug
		cout << "Enter numbers, press 0 to stop" << endl;
		cin >> data;
	} while (data != 0);

	return head;
}

int main()
{

	Node *head, *curr, *next;
	head = getListFromUser();
	next = head;
	while (next != NULL)
	{
		curr = next;
		next = curr->m_next;
		cout << "Next #: " << curr->m_data << endl;
		delete curr;
	}
	return 0;
}

[Ganado]

	do
	{
	    	if (data == 0)
		{
		    cout << "NULL" << endl;
		    return 0;
		}
		
		if (head == NULL)
		{
			head = newnode;
			head->m_next = NULL;
		}

I don't think this belongs in the loop, because this part of the logic only happens once, at the beginning.

			current = head;
			while (current != NULL)
			{
				current = current->m_next;
			}
			current = newnode;

This looks odd, so it probably isn't doing what you want to.
You assign head to current, but then you keep re-assigning current until current is NULL. Then you assign current to be newnode. In other words, your lines 42 to 26 don't do anything useful, because you are re-assigning current right afterward.

You also never allocate any more memory beyond the first node -- you need to call new every time you want to allocate a new node.

________________________________________________________

This probably could be beautified a bit further, but this should fix your problems:

#include <iostream>
using namespace std;

class Node
{
  public:
	int  m_data;
	Node *m_next;
};

Node* getListFromUser()
{
	int data = 0;     // It's good to initialize things so you know what to expect
	Node *head = NULL;    // the newnode variable is redundant and just makes things more convoluted
	Node *current = NULL;

	cout << "Enter numbers, press 0 to stop: ";
	cin >> data;
	
	if (data == 0)
	{
	    cout << "NULL" << endl;
	    return NULL;
	}

	// At this point, we know we should have at least 1 valid node in the linked list
	
	head = new Node;
	head->m_data = data;
	head->m_next = NULL;
	current = head;
	
	cin >> data;
	while (data != 0)
	{
	    current->m_next = new Node; // allocate the next node
	    current = current->m_next;
	    current->m_data = data;
	    current->m_next = NULL;

	    cin >> data;
	}

	return head;
}

int main()
{
	Node *head = getListFromUser();
	Node *curr = head;

	while (curr != NULL)
	{
	    cout << "Next #: " << curr->m_data << endl;
	    Node *next = curr->m_next; // copy pointer to next before we delete current
	    delete curr;
	    curr = next;
		
	}
	return 0;
}