1. COMS W1004 Introduction to Computer Science June 9, 2008

2. Announcements Homework #2 due at the beginning of class Wednesday –Submit a paper copy of the Theory part –Electronic submission of Programming part Office hours this week –Tomorrow: 5:30-6:30 (Milind), 7:30-8:30 (Aditi) –Wednesday: by appointment (Chris)

3. Last Time von Neumann Architecture Review of binary numbers and Boolean logic Encoding Transistors, gates, and circuits Reading: S&G 4

4. Today Object-oriented programming Classes and Objects –public vs. private –encapsulation –static –scope Writing methods: arguments and parameters Constructors Advice on Homework #2 Reading: L&L 4, 6.1-6.4

5. Advice on Homework #2 Extra credit: You need to check two things –The fifth and tenth characters must be dashes –The other twelve characters must be numbers Security checks –It’s okay if some logic is repeated, i.e. you don’t use functions –Try to use “lazy evaluation” –The program should end as soon as it’s determined that a check has failed