1. A3 is due after the break, but start on it NOW
Read HyperText entry on Study/work habits
When given new tasks to get done,
Procrastinate right from day one.
You think that's not fine?
It gives you more time
To catch up at last as you're done.

2. Assignment A3: Linked Lists
Idea: maintain a list (2, 5, 7) like this: 2 a1 a6 v
next 5 a6 a8 v
next 7 a8
null v
next h a1
This is a singly linked list
To save space, we write names like a6 instead of 2

3. How to insert a node at the beginning2 a1 a6 v
next 5 a6 a8 v
next 7 a8
null v
next h a1
(2, 5, 7) h a3 2 a1 a6 v
next 5 a8 7
null 8
(8, 2, 5, 7) 3

4. How to remove successor of a node in the middle2 a1 a6 v
next 5 a6 a2 v
next 8 a2 a8 v
next 7 a8
null v
next h a1 k a6
(2, 5, 8, 7) h a1 2 a6 v
next 5 a8 7
null 8 a2 k
(2, 5, 7) 4

5. Assignment A3: Generics
public class LinkedList { void add(Object elem) {…} Object get(int index) {…} }
Values of linked list are of class Object
public class LinkedList<E> { void add(E elem) {…} E get(int index) {…} }
You can specify what type of values
ns = new LinkedList<Integer>();
ns.add("Hello"); // error
ns.add(5); String s = ns.get(0); // error int n = ns.get(0);
ss = new LinkedList<String>();
ss.add("Hello");
ss.add(5); // error String s = ss.get(0); int n = ss.get(0); // error

6. Assignment A3: Inner class
public class DList<E> { private Node first; … public E first() { return first.val; } … private class Node { private Node prev; private E val; } }
field
method
class
Outer class can and should use fields of class Node, even though they are private.

7. Quiz
Name _________ Netid _________ Write the steps in evaluating the new expression new C(“b”)
Write the steps in evaluating the new expression
Write the steps in executing a method call.
You need to know these:
To answer questions about Java
To help debug programs
For the prelim
In a constructor, do I have to store 0 in an int field?
When is space allocated for a local variable?