linked list- JAVA

[indianj]

i was going through my java exercise and here is exercise that i did not get it. let me know if you know anything.

suppose cursor refers to a node in a linked list (using the Node class with instance variables called data and link). What boolean expression will be true when cursor refers to the tail node of the list?

a) (cursor==null)
B) (cursor.link==null)
c) (cursor.data==null)
D) (cursor.data==0.0)
E) none of the above

[oceanebelle]

From my stock knowledge:

I would say... B is the right answer.

since it is not pointing to another NoDE element.

node-> node -> node -> node(tail)

A is wrong since
node-> node -> node(actual tail) -> null... if i'm not mistaken there's a programming term for the type of problem for this one... it is not garbage though.
C does not really tell anything because it only talks about the data. The node might have no data but the Link variable might be referencing another node.
D again refer to explanation in C it should be more or less same explanation except in this case 0 is the value.


That is, If I still remember my classes in OOP and Programming right.

[dglienna]

A) or B) [not sure of the JAVA class]

Singly-linked list

The simplest kind of linked list is a singly-linked list (or slist for short), which has one link per node. This link points to the next node in the list, or to a null value or empty list if it is the last node.

http://en.wikipedia.org/wiki/Linked_list

ALSO THIS:

 // source file link.java

        public class link {
                public int value;              // value of element
                public link next;              // reference to next
        
                // constructor
                public link(int n, link ln)
                {
                        value = n;
                        next = ln;
                }

                public static void main(String args[])
                {
                        // initialize list head
                        link head = null;

                        // add some entries to list
                        for (int i = 1; i <= 10; i++)
                                head = new link(i, head);

                        // dump out entries
                        link p = head;
                        while (p != null) {
                                System.out.println(p.value);
                                p = p.next;
                        }
                }
        }

[oceanebelle]

A) or B) [not sure of the JAVA class]



http://en.wikipedia.org/wiki/Linked_list

thus it is B and no other, it does not say that the NODE be null, which in the case of A the cursor or node is null itself.

In the definition it just says link will have a value null or empty.

[CornedBee]

if i'm not mistaken there's a programming term for the type of problem for this one

Well, if cursor is NULL then you have a past-the-end pointer.

[indianj]

thanks alot everyone. i think i have better idea how cursor works.