Java Reference
In-Depth Information
To finish the job, all we need to do is link the previous node to the new node. We
want to move the arrow to the node named by
temp
. The following finishes our job:
previous.link = temp;
The new node is inserted in the desired place, but the picture is not too clear. The
fourth picture is the same as the third one; we have simply redrawn it to make it neater.
To summarize, the following two lines insert a new node with
newData
as its data.
The new node is inserted between the nodes named by
previous
and
position
.
temp =
new
Node(newData, position);
previous.link = temp;
previous
,
position
, and
temp
are all variables of type
Node
. (When we use this code,
previous
and
position
will be instance variables of an iterator and
temp
will be a
local variable.)
Just like deletion, special cases exist for insertion that must be handled. If the list is
empty, then addition is done by adding to the front of the list. If the
position
variable
is
null
, then the new node should be added to the end of the list.
Self-Test Exercises
11. Consider a variant of the class in Display 15.17 with no
previous
local
variable. In other words, there is no reference kept to the node that links to the
current node position. How could we modify the
delete
method to delete the
position
node and still maintain a correct list? The solution is less effi cient
than the version that uses
previous
.
12. Consider a variant of the class in Display 15.17 with no
previous
local
variable. In other words, there is no reference kept to the node that links to the
current node
position
. Write a method
addAfterHere(String newData)
that adds a new node after the node in
position
.
13. Complete the defi nition of the method
changeHere
in the inner class
List2Iterator
in Display 15.17 .
14. Given an iterator pointing somewhere in a linked list, does
i.next( )
return
the value that
i
is referencing prior to the invocation of
i.next( )
or does it
return the value of the next node in the list?
