Linked Lists - Building Java Programs: A Back to Basics Approach - page 944

data
3

next data

5

next data

2

next
/

front

current

At that point, you can assign current.next to be a new node with 17 in it:

current.next = new ListNode(17);

In this case, you are changing the currently null value in that last node to instead
link to a new node with 17 in it:

data
3

next data

5

next data

2

next data

17

next
/ front

current

You have been preparing to write code for the appending add . So this code would
be included inside a method, and you would have to alter it to use the name of the
parameter:

public void add(int value) {
ListNode current = front;
while (current.next != null) {
current = current.next;

}
current.next = new ListNode(value);

}

Even this code isn't quite correct, because you have to deal with the special case in
which the list is empty:

public void add(int value) {
if (front == null) {
front = new ListNode(value);
} else {
ListNode current = front;
while (current.next != null) {
current = current.next;

}
current.next = new ListNode(value);

}

}