Java™ How to Program, Seventh Edition

17.4. Self-Referential Classes

A self-referential class contains an instance variable that refers to another object of the same class type. For example, the declaration

class Node
{
   private int data;
   private Node nextNode; // reference to next linked node

   public Node( int data ) { /* constructor body */ }
   public void setData( int data ) { /* method body */ }
   public int getData() { /* method body */ }
   public void setNext( Node next ) { /* method body */ }
   public Node getNext() { /* method body */ }
} // end class Node

declares class Node, which has two private instance variables—integer data and Node reference nextNode. Field nextNode references a Node object, an object of the same class being declared here—hence, the term “self-referential ...