Introduction. CS 101 Instructors –Jim Cohoon Office –Olsson 221 –Hours: Monday 3:30 – 5:00, Tuesday 10:00 – 11:00 –Email id: –Aaron Bloomfield Office

Introduction

CS 101• Instructors

– Jim Cohoon• Office

– Olsson 221– Hours: Monday 3:30 – 5:00, Tuesday 10:00 – 11:00– Email id:

– Aaron Bloomfield• Office

– Olsson 228D– Hours: Monday 1:00 – 2:00, Wednesday 10:00 =

11:00, Friday 10:00 – 11:00– Email:

• Both instructors also accept appointment

Objectives• Provide opportunities for the demonstration of student

comprehension through lab demonstrations, tests, and homework projects

• Provide a variety of learning experiences to instill familiarity with the fundamentals of computing systems and software development

Objectives• Provide opportunities for the demonstration of student

comprehension through lab demonstrations, tests, and homework projects

• Provide a variety of learning experiences to instill familiarity with the fundamentals of computing systems and software development– Understand common fundamentals of programming– Understand fundamentals of object-oriented programming in

Java– Appreciate importance of software engineering and

Computer Science– Develop programs to solve specified problems.– Use the Java SDK environment to create, debug and run

simple Java programs

Prerequsites• Genuine interest in learning the material

• Agree to abide by the course honor policy

Honor policy• When there is doubt regarding what is allowable or honorable,

you will ask before doing it

• When possible with honor, you will help your classmates learn and improve

• You will seek honorable help before succumbing to frustration

• You will pledge your work that you have neither given nor received unauthorized help

• You will not describe or show problems to anyone who has not yet completed a quiz or exam

• You will not receive information on problems before completing a quiz or exam

• By default, collaboration is limited to the discussion of ideas – Code is not distributed either electronically or on paper

– Any exceptions will be specifically noted on an assignment

Honor policy• Academic irregularities may result in failure of the course and be

brought to the honor committee

• Beware of MOSS

Text• Java Program Design, McGraw-Hill, 2005, ISBN 0072948655.

– Cohoon and Davidson

Grading criteria• 5% – Laboratory participation

• If you miss more than 2 labs, you are subject to course failure for the course

• If for a valid reason you are unable to do your lab, there will be a make-up lab on Sunday night, provided that you get permission prior to your scheduled lab

• 10% – Laboratory programming quizzes

• 35% – Homework assignments

• 25% – Midterms• September 29, October 27, November 22

– Your worst midterm will be weighted ½ of your other midterms

• 25% – Final exam• Scheduled time is Monday December 13 at 7:00 PM• See other instructors for make-ups; i.e., APMA 310 and

ECON 201

• Average grade will be at least a B-

Grading criteria• Average grade will be at least a B-

Home directory service• All assignments and lab files must be kept on your home

directory– www.virginia.edu/homedir

Sections• CS 101

– Students have little or no programming experience– Mandatory scheduled closed labs

• CS 101E– Students with programming experience– Open labs that are to be completed by a scheduled time

• All students take same quizzes and tests, and do the same assignments

• Course curve is based on the section with the lower average

Let’s begin• Goal

– Teach you how to program effectively

• Skills and information to be acquired– Mental model of computer and network behavior– Problem solving– Object-oriented design– Java

Let’s begin• Goal

– Teach you how to program effectively

• Skills and information to be acquired– Mental model of computer and network behavior– Problem solving– Object-oriented design– Java

Computer Organization• Computer advertisement specification

– Intel® Pentium 4 Processorat 3.06GHz with 512K cache

– 512MB DDR SDRAM– 200GB ATA-100 Hard Drive

(7200 RPM, 9.0 ms seek time)– 17” LCD Monitor– 64MB NVIDIA GeForce4

MX Graphics Card®– 16x Max DVD-ROM Drive– 48x/24x/48x CD-RW Drive– 56K PCI Telephony Modem– Windows XP Home Edition SP2 ®– 10/100 Fast Ethernet Network Card

Computer Organization

Input Devices

CentralProcessing Unit

Memory

Output Devices






3.06 billion operationsper second






512 million bytes ofmemory that can betransferred at double

the normal rate

A byte is 8 bits

A bit is a 0 or a 1






Stores 200 billionbytes of data. You want high RPM and

low seek time.0.009 seconds is

average






17” on the diagonal.Resolution up to1,280 by 1,024

pixels






Microprocessor fordisplaying images with

64 million bytes ofmemory. More memorysupports more colorsand higher resolution






Reads DVDs 16 timesfaster than a basic DVD

drive. Can hold up to8 billion bytes of data






Can read and writeCDs. Can hold 650

million bytes of dataReads at 48 timesfaster and writes

24 times faster thana basic drive






Can send or receiveup to 56 thousand

bits per second






Computer operatingsystem using a

graphical interface






Can send or receivedata at two rates –

10 or 100 million bytesper second

Problem Solving• Remember

– The goal is not a clever solution but a correct solution

Problem Solving• Accept

– The process is iterative• In solving the problem increased understanding might

require restarting

Problem Solving• Solutions

– Often require both concrete and abstract thinking• Teamwork

Problem Solving Process• What is it?

– Analysis– Design– Implementation– Testing



Determine the inputs, outputs, and other components of the problem

Description should be sufficiently specific to allow you to solve the problem



Describe the components and associated processes for solving the problem

Straightforward and flexible

Method – process

Object – component and associated methods



Develop solutions for the components and use those components to produce an overall solution

Straightforward and flexible



Test the components individually and collectively

Problem Solving Process

Testing

Design

Analysis

Implementation

Determineproblem features

Describe objectsand methods

Produce theclasses and code

Examine forcorrectness

Rethink asappropriate

Tips• Find out as much as you can

• Reuse what has been done before

• Expect future reuse

• Break complex problems into subproblems

Engineering software• Complexity of software grows as attempts are made to make it

easier to use– Rise of wizards

Software engineering• Goal

– Production of software that is effective and reliable, understandable, cost effective, adaptable, and reusable



• Work correctly and not fail



• Because of the long lifetime many people will be involved– Creation– Debugging– Maintenance – Enhancement

• Two-thirds of the cost is typically beyond creation



• Cost to develop and maintain should not exceed expected benefit



• Design software so that new features and capabilities can be added



• Makes sense due to the great costs involved to have flexible components that can be used in other software

Object-oriented design• Purpose

– Promote thinking about software in a way that models the way we think and interact with the physical word

• Object– Properties or attributes– Behaviors

Object-oriented design• Class

– Term for a type of software object

• Object– An instance of a class with– specific properties and

attributes

Java and the Internet

I think ...

JVMJava

Compiler

DisplayForecast.java

DisplayForecast.class DisplayForecast.class

Modem Modem

Your machine Your friend's machine

Internet

Documents

Introduction. CS 101 Instructors –Jim Cohoon Office –Olsson 221 –Hours: Monday 3:30 – 5:00, Tuesday 10:00 – 11:00 –Email id: –Aaron Bloomfield Office