If the list is empty, headPtr contains null and traverse() will immediately return to its caller.

Traverse

Here is traverse()

  public void traverse()
  {
    Node p = headPtr;
    while ( p != null )
    {
      System.out.print( p );
      p = p.getNext();
    }
  }

Here is a non-empty list:

The node pointer p is advanced through the list until it reaches the last one.

Will traverse() print out the last Node?