Thread: Don't Understand Outputting Linked Lists Elements

I'm currently studying Jumping into C++.

I understand the concept of Linked Lists, but using linked lists has me stumped.

In the below code (from linked list tutorial), I have "conductor = root; commented out (//) before the second if statement. It outputs "test" and "42".

If I "un-comment" the "conductor = root" line, the output is "test" and "12".

question - why doesn't the code make it to the second while statement and cout "test 123" for both cases?

Code:

#include <iostream>
#include <cstddef>


using std::cout;
using std::cin;
using std::endl;


struct node
{
    int x;
    node *next;
};


int main ()
{
    cout<< " test \n ";
    node *root;         // This will be the unchanging first node
    node *conductor;    // This will point to each node as it traverses the list


    root = new node;    // Sets it to actually point to something
    root->next = 0;     // Otherwise it would not work well
    root->x = 12;
    conductor = root;   // The conductor points to the first node
    if ( conductor != 0)
    {
        while ( conductor->next != 0)
            conductor = conductor->next;
    }
    conductor->next = new node;     // Creates a node at the end of the list
    conductor = conductor->next;    // Points to that node
    conductor->next = 0;            // Prevents it from going any further
    conductor->x = 42;


    //conductor = root;


    if (conductor != 0 )
    {
        while ( conductor->next = 0 )
        {
            cout<< "test 123" << endl;
            cout<< conductor->x;
            conductor = conductor->next;
        }
        cout << conductor->x;
    }
}

Thank You!

Line 50 needs to be there so it COUT's the last element (42). The last element has next = 0 and the while loop goes until next != 0.

I think linked lists is finally starting to gel.

Modern C++ comes with lots of containers and algorithms so it would be much better to learn to use them.
It has some educational benefit to learn to write some of your own, but this is for advanced users,
not for beginner or intermediate level.