Question

In a lot of examples I’ve read a simple getListLength() function would look something like this:

int getListLength(struct node *head)
{
    struct node *temp = head;
    int iCount = 0;

    while (temp)
    {
        ++iCount;
        temp = temp->next;
    }

    return iCount;
}

What strikes me as unneeded is the declaration of a local pointer (in this case *temp) that copies the passed parameter. If I recall correctly, passed parameters obtain their own copies. Thus, there won’t be a need for a local pointer that copies the *head just because the *head is a copy itself, right?
In other words, would it be correct to discard the *temp pointer and use head everywhere instead?

Answer 1

Yes, it’s a copy, so yes, it would be correct.

int getListLength(struct node* head)
{
    int iCount = 0;

    while (head)
    {
        ++iCount;
        head = head->next;
    }
    return iCount;
}

Why don’t you execute it and see for yourself?