Memory address in linked list C++

Question

I have created an extremely simple linked list example in C++ to practice some interview questions. I am having one strange issue that I can't really seem to understand:

while( cur )
{
    cout << "Index: " << indx << endl <<
        "Current Add:\t" << &cur << endl <<
        "Value:\t\t" << cur->val << endl <<
        "Next Add:\t" << &cur->next << endl << 
        "Ran Add:\t" << &cur->ran << endl <<
        "Ran Val:\t" << cur->ran->val << endl << endl;
    cur = cur->next;
    ++indx;
}

I am using this code to iterate through and print the list. It works fine. HOWEVER. The address of the current node is always the same. The list contains a int value and a pointer to a next node as well as a pointer to a random address in the list. The addresses and Values are assigned correctly and I can see the "next" address fine. But when it assigns that to the current node it always seems to point to the same address..

The only thing I can assume is that during execution it moves "cur" to some register and so always shows this address rather than the location in memory. Does this make sense? Would this be correct or is there something I am missing? This does not affect my implementation in any way it is just some strange behaviour that I would like to better understand.

Thanks

The address of the current node is the value of cur. You are instead printing &cur - the address at which the variable cur itself is located. Naturally, cur doesn't magically jump around in memory - its value changes, but its address doesn't. — Igor Tandetnik
– Igor Tandetnik, Commented May 18, 2015 at 2:52

Bill Lynch · Accepted Answer · 2015-05-18 02:53:18Z

6

You're printing:

"Current Add:\t" << &cur << endl <<

This is the address of the variable:

struct node *cur;

The address of that pointer (not the address it points to!) will of course not change. You probably intended to write:

"Current Add:\t" << cur << endl <<

answered May 18, 2015 at 2:53

Bill Lynch

82.4k16 gold badges132 silver badges181 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

pipedreams2 Over a year ago

Oh god, of course, stupid mistake. Thanks for the quick answer.

Collectives™ on Stack Overflow

Memory address in linked list C++

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related