Linked lists - Data Structures and Problem Solving Using Java - page 637

1 /**
2 * This is the doubly linked list node.
3 */
4 private static class Node<AnyType>
5 {
6 public Node( AnyType d, Node<AnyType> p, Node<AnyType> n )
7 {
8 data = d; prev = p; next = n;
9 }
10
11 public AnyType data;
12 public Node<AnyType> prev;
13 public Node<AnyType> next;
14 }

figure 17.21
Node nested class for
standard LinkedList
class

private. It could matter if Node was to be extended inside of LinkedList , and this
would argue toward making the data private. On the other hand, since in our
implementation, LinkedList is accessing the Node 's data fields directly, rather
than invoking methods, it seems more appropriate to mark the data as public.
The implementation of LinkedList begins in Figure 17.22, where we
have the constructors and clear . All in all, little is new here; we combined

1 /**
2 * Construct an empty LinkedList.
3 */
4 public LinkedList( )
5 {
6 clear( );
7 }
8
9 /**
10 * Construct a LinkedList with same items as another Collection.
11 */
12 public LinkedList( Collection<? extends AnyType> other )
13 {
14 clear( );
15 for( AnyType val : other )
16

figure 17.22
Constructors and
clear method for
standard LinkedList
class

add( val );

17 }
18
19 /**
20 * Change the size of this collection to zero.
21 */
22 public void clear( )
23 {
24 beginMarker = new Node<AnyType>( null, null, null );
25 endMarker = new Node<AnyType>( null, beginMarker, null );
26 beginMarker.next = endMarker;
27
28 theSize = 0;
29 modCount++;
30 }