COS 126 Midterm Exam Information, Spring 2008

Q+A.

There will be a Q+A Tuesday night, March 11, 8:30-10:00pm, Room Friend 101

The precept before the exam will have a substantial amount of time for Q+A and review.

Rules: Written exam.

50 minutes, during last lecture time slot before break.
Closed book, closed note.
You may bring one 8.5-by-11 sheet (one side) with notes in your own handwriting to the exam.
No calculators (or computers!)

Rules: Programming exam.

50 minutes, during last precept time slot before break.
Open book, open note, open computer --- yes, including the booksite!
Make sure that your laptop is charged (in case there aren't enough outlets in your precept room). If you don't have a working laptop, tell your preceptor.
Set up an empty directory on your laptop that includes a copy of StdIn.java and StdDraw.java.

Material covered.

The exam covers everything in the first half of the course:

Introduction to Programming in Java, Chapters 1-2 (except 2.4), 4.1.
Introduction to Programming in Java, Booksite 5.1-5.3, beginning of 5.4 (up through TOY idioms), 9.6.
Lecture notes 1-10. Lecture notes 11 through slide 9.
Programming assignments 0-4.

The first part of the exam (in lecture) covers all of the above. It will be multiple-choice or short answer questions on the important material. The best way to prepare for this part of the exam is to read the book and to study the lecture notes, including the Challenge questions that appeared in lecture. You are not responsible for knowing details of complicated applications examples like the random web surfer or IFS.

The second part of the exam in precept is strictly about programming. You will be asked to write a program from scratch (a mini programming assignment). Given the time limitation, this program will not be conceptually difficult, just a test of your ability to write a program that solves a simple problem. The best way to prepare for this part of the exam is to work a few of the easy exercises in the book and on the booksite that call for writing small programs.

List of topics.

This list is a sumary of the main topics on the exam, for your use as a checklist when studying. Do you understand the basic ideas behind each of these topics? If so, fine; if not, reread the appropriate sections in the book and lecture slides.

Basic data types. boolean, char, int, double, String
Operators. + * - / % ++ -- ! && || < <= > >= == !=
Control structures. Conditionals (if, if-else), loops (for, while).
Arrays. 1D and 2D arrays. Reasons to use arrays. Java code for arrays ([] and new)
Input and output. Standard input, standard output, standard graphics. Redirection of standard input and standard output, piping.
Functions. Scope, overloading, signatures, flow of control.
Recursion. Tracing through recursive functions, recursive graphics.
Number representation. Binary, decimal, hexadecimal. Two's complement notation.
Performance. Predicting running time of simple programs.
TOY machine. Basic features and components (and how it relates to Java and real computers). Tracing through small TOY programs that do assignment statements, arithmetic, loops, conditionals, arrays. We will supply the TOY reference card.

APIs.

You should be familiar with the following static methods (the ones we've encountered frequently in the lectures and assignments). If we want you to use some other library function, we'll remind you how it works.

Math.sqrt()
Math.abs()
Math.sin()
Math.cos()
Math.exp()
Math.log()
Math.random()
Math.E
Math.PI

System.out.println()
System.out.print()

Integer.parseInt()
Double.parseDouble()

StdIn.readInt()
StdIn.readDouble()
StdIn.readString()
StdIn.isEmpty()

StdDraw.line()
StdDraw.point()
StdDraw.circle()
StdDraw.setXscale()
StdDraw.setYscale()
StdDraw.clear()
StdDraw.show()
StdDraw.picture() 
StdDraw.filledPolygon()

Old Exams.

A good way to practice for the midterm is to solve problems from old exams.

Warning 1: Some old exams include questions on topics that we have not covered this semester, for example circuits, TOY architecture, and percolation.

Warning 2: Studying questions that ask you to write code is worthwhile, but bear in mind that old exams were two hours, closed book, no computers. This year, the written exam will not have questions that ask you to write a significant amount of code and the purpose of the programming exam is to test your ability to write code. Also, the time allotment for the written exam is half as long, so there will not be as many questions this year as in the past.