In this chapter, we look at the use of pointers to build  "linked"  data
types.  A linked data type allows separate objects to be linked together
into more complex information structures.  There are  many  examples  of
such linked structures including lists, queues, trees and graphs.  It is
not the goal of this course to explore these in detail -  this  is  left
to  a  later  course  on Data Structures. Instead, we focus on the rela-
tively simple example if a list in  order  to  demonstrate  the  overall
approach.

This chapter introduces the following key concepts:

o    Linking objects through pointers.

o    Making one class a "friend" to another.