Introduction

The purpose of this project component is to provide a first experience in the actual writing of computer programs. Using a relatively simple introductory scripting language (Python), you will create program code in an editor (Notepad), save it to your disk, and run it from the command line prompt.

You will gain experience in planning, writing, debugging, documenting, and running simple programs. Learning Python serves as a convenient stepping-stone to more complex object-oriented languages, such as Java.

In this project, you will use online resources, including downloadable Python tools and tutorials.

Before writing programs, it is useful to plan the programming steps and actions by writing an algorithm. An algorithm is a set of plain English language commands or steps, each of which is then replaced by the appropriate command line for the programming language used. This technique becomes less useful when using complex object-oriented languages such as Java, but may be helpful in the early stages of learning to design programs. You will write algorithms for your first two programming exercises in this project.

The project will be graded for completeness and correct functioning of programs.

Acquiring the Tools

Download and install Python version 2.2 or higher by following the instructions at the Python download site.

The downloaded file will be called Python-2_2.exe. After downloading, run this file to complete the installation. You can view the installed components from your “Start” list.

Writing Algorithms

In the traditional approach to programming, the program is seen as a series of steps, which may include branches and loops. A branch occurs when a program may go in two or more different directions, depending upon a logical condition or a choice made by the user. A loop is a situation where a particular step, or series of steps, may be repeated until a certain condition or choice occurs.

The following simple example of an algorithm includes both elements, and describes a simple program for performing addition or multiplication.

Step 1—display the program name “Addition and Multiplication”

Step 2—display the options menu “(A)dd, (M)ultiply”

Step 3—request and store input of user choice A or M as “choice”

Step 4—if “choice” does not equal “A” or “M”, go to Step 9

Step 5—request and store the first number to be used as variable X

Step 6—request and store the second number to be used as variable Y

Step 7—if “choice” = “A” go to Step 11

Step 8—if “choice” = “M” go to Step 13

Step 9—display message “Choose A or M”

Step 10—go to Step 3

Step 11—display “Sum is” X+Y

Step 12—go to Step 3

Step 13—display “Product is” X*Y

Step 14—go to Step 3

Writing, Storing, and Running Python Programs

The actions involved in creating and running Python programs are relatively simple:

Input the code using Notepad, and save the file as *.py (e.g., prog1.py). Save your programs in the Python folder on your hard disk.

Open the MS-DOS prompt window.

Change directory from Windows to Python22 (enter “cd\”, followed by “cd python22”).

Run the Python interpreter on your program by typing python filename.py, where “filename” is the actual name of your saved *.py file (e.g., python prog1.py).

Learning Python

Go to A Beginner’s Python Tutorial, and work through the first seven lessons.

Please note that the tutorial describes running programs for an earlier version of Python, and follows:

“Edit” menu-> “Run Script”

In later versions of Python, programs are run as follows:

“Run” menu-> “Run Module” (or simply hit F5)

Note: If you need more help, the internet has several instructive sites, for example, www.learnpython.org/.

Programs

The programs you will write for this project are copied with permission, or adapted from, the exercises in A Beginner’s Python Tutorial.

Each program should be written, tested, and debugged. The first two programs should also be fully commented, with each line documented by a descriptive comment. The remaining programs should have a single comment line at the beginning to describe the function of the program. All programs should start with a display of your name, student id#, and the program number and name. When storing the files, name them as prog1.py, prog2.py, etc.

EXAMPLE OF AUTHOR/PROGRAM INFORMATION OUTPUT

Program author: B. Rubble

ID#: 1234567

Program 1—Math Functions

PROGRAM 1—MATH FUNCTIONS

Write an algorithm for a program that shows the use of all six math functions. Write, test, and debug the program using Python.

SAMPLE OUTPUT (not including author/program information)

ADDITION: 2+2=4

SUBTRACTION: 4-2=2

MULTIPLICATION: 4*2=8

DIVISION: 4/2=2

EXPONENT: 2**3=8

REMAINDER: 5%2=1

PROGRAM 2—USING INPUT

Write an algorithm for a program that receives, as input from the user, 2 string variables and 2 integer variables; then joins together and displays the combined strings; and finally multiplies the two numbers on a new line. Write, test, and debug the program using Python.

SAMPLE OUTPUT (not including author/program information)

Input string 1? Billy

Input String 2? Bob

Input integer A? 23

Input integer B? 2

BillyBob

46

PROGRAM 3—LOOPS AND IF CONDITIONS

Write a program that requests a password after the author/program information is displayed. Make the password “hello”. The program should then ask the user for their name: if the name entered is the same as your name, the program should respond with “What a great name!”; if they enter “Madonna” or “Cher”, the program should respond “May I have your autograph, please?”. For any other input, the program should respond with “(input name), that’s a nice name”.

SAMPLE OUTPUT (including author/program information)

Program author: Barney Rubble

ID#: 1234567

Program 3—LOOPS AND IF CONDITIONS

Password? unicorn

Password? opus

Password? hello

Welcome to the second half of the program!

What is your name? Barney

What a great name!

ALTERNATE OUTPUTS

What is your name? Cher

May I have your autograph, please?

What is your name? Bill

Bill, that’s a nice name.

PROGRAM 4—FUNCTIONS

Rewrite the area.py program (shown below, or in the Creating Functions section of the tutorial) so that it has separate functions for the perimeter and area of a square, a rectangle, and a circle (3.14 * radius**2). This program should include a menu interface that has ‘exit the program’ as one of its choices.

SAMPLE PROGRAM EXECUTION

Area.py

#This program calculates the perimeter and area of a rectangle

print “Calculate information about a rectangle”

length = input(“Length:”)

width = input(“Width:”)

print “Area”,length*width

print “Perimeter”,2*length+2*width

SAMPLE OUTPUT (not including author/program information)

CALCULATIONS MENU

1) AREA (SQUARE)

2) AREA (RECTANGLE)

3) AREA (CIRCLE)

4) PERIMETER (SQUARE)

5) PERIMETER (RECTANGLE)

6) PERIMETER (CIRCLE)

7) EXIT

INPUT MENU CHOICE (1,2,3,4,5,6 OR 7)? 2

YOU HAVE CHOSEN AREA (RECTANGLE)

INPUT WIDTH? 8

INPUT LENGTH? 4

AREA IS 32

INPUT MENU CHOICE?

Packaging and Submitting

When submitting your project, use WinZip or a compatible program to compress all the required files into a single archive. There should be four files in total: prog1.py, prog2.py, prog3.py, and prog4.py.

CIS 36A :: LAB 04 – Introducing Classes, Objects and Methods

Student Name:

Instructions:

1. Make a copy of assignment template. Go to File => Make a copy (or download as a Word file.)
2. Complete definitions and attach Snipping Photos where appropriate
3. Place your name in the Title of each Assignment
   1. For Example: CIS 36A- Assignment 1 – Basic Concepts –  Irfan O.
4. Use the book or do online research to find answers. 
5. Write your answers using a different font color. Find your own unique color. 
6. Write answers in your own words. DO NOT COPY & PASTE from anywhere.
7. Submission: When done, go to File -> Download as -> Microsoft Word and then upload the file to Canvas. 

Task 1: Definitions & Concepts

Instructions: Briefly answer the questions below.

1. Keywords: To you best knowledge, describe below words: 
   1. class =>  
   2. method => 
   3. return  =>
   4. void => 
   5. this =>  
   6. object => 
   7. constructor => 
   8. new => 
2. What is the difference between a class and an object?
   => 
3. How is a class defined?
   => 
4. How must a method return if it returns a value?
   => 
5. What name does a constructor have?
   => 
6. If a method returns no value, what must its return type be?
   => 

Task 2: Understanding Programming

Instructions: Answer each question below. Try to understand and explain the code. Do not put an IDE code screenshot. 

1. Exercise 15: Suppose you have a class MyClass with one instance variable x. What will be printed by the following code segment?
   MyClass c1 = new MyClass();
   c1.x = 3;
   MyClass c2 = c1;
   c2.x = 4;
   System.out.println(c1.x);
   Explain your answer.
   => 
2. Exercise 16: Suppose a class has an instance variable x and a method with a local variable x.
   1. If x is used in a calculation in the body of the method, which x is being referred to?
      => 
   2. Suppose you needed to add the local variable x to the instance variable x in the body of the method. How would you do so?
      => 
3. Exercise 17: The following method has a flaw (in fact, due to this flaw it will not compile). What is the flaw?

void displayAbsX(int x) {
    if (x > 0) {
        System.out.println(x);
    return;
    }
   else {
        System.out.println(-x);
        return;
   }
   System.out.println(“Done”);
 }
=> 

1. Exercise 18: Create a method max( ) that has two integer parameters x and y and returns the larger of x and y.
   => 
2. Exercise 19: Create a method max( ) that has three integer parameters x, y, and z, and it returns the largest of the three. Do it two ways: once using an if-else-if ladder and once using nested if Statements.
   => 
3. Exercise 21: Find all the errors (if any) in the following class declaration:
   Class MyCla$$ {
       integer x = 3.0;
       boolean b == false

       // constructor
       MyClass(boolean b) { b = b; }
       int doIt() {}
       int don’tDoIt () { return this; }
   }
   => 

Task 3: Programming Exercises

Instructions: Use any IDE to write and execute below exercises from the book chapter 3. Attach Snipping photos of your source code and execution of the code in the console. Make sure to create separate files for each exercise.

Chapter Examples: Follow the lectures to do below programs with the instructor.  

1. Day 1: MethodDemo 
2. Day 2: The last version of your VehicleDemo class
3. Create a BankAccount class with one integer instance variable called balance. Create a constructor with no initial parameters.  Create three methods: one for deposit, one for withdrawal, one for get balance. 

TRY THIS

1. TRY THIS 4-1 (Do not submit this):
2. TRY THIS 4-2:

Chapter Exercises: Do the following chapter exercises.

• Exercise 13: Die, DieDemo
• Exercise 14: Car, CarTester
• Exercise 22: Swapper
• Exercise 24: USMoney
• Exercise 25: Date
• Exercise 26: DoIt

Lab Assessment Questions

1. What does ACL stand for and how is it used?

2. Why would you add permissions to a group instead of the individual?

3. List at least three different types of access control permissions you can enable

for a file using icacls.exe.

4. Which access control permissions allow you to change files and/or folders?

5. If you don’t remember the syntax when using icacls.exe, what command do

you type to see the options?

6. Without using the icacls.exe tool, how could you view and modify the privileges

of the files or folders of a shared drive?

7. Where do permissions modified using the icacls.exe tool appear in the folder

Properties?

Learning Objectives and Outcomes

Describe the capabilities of three tools used to recover deleted Macintosh files.

Recommend one of the tools for use in a given scenario.

Assignment Requirements

You are an experienced digital forensics specialist for DigiFirm Investigation Company. One of your clients is a small music production company. One day you receive a phone call from Andrea, the owner and president of the music company.

Andrea believes one of her employees, a sound technician, has been stealing intellectual property from the company. She thinks he is copying original music scores and then selling them to upstart musicians, claiming that he wrote them. Andrea checked the employee’s computer the previous night and thinks he has been deleting the files to cover his tracks. He uses a Macintosh computer.

There are several tools available for recovering files that have been deleted from a Macintosh computer, including:

Mac Keeper Files Recovery, http://mackeeper.zeobit.com/

Mac Undelete, http://www.macundelete.com/

Free Undelete Mac, http://www.freeundeletemac.com/

For this assignment:

Research three specific tools that can aid in recovering deleted Macintosh files.

Write a report about the capabilities of the tools.

Recommend one of the tools for use in this case and justify your recommendation.

Required Resources

Course textbook

Internet access

Submission Requirements

Format: Microsoft Word

Font: Arial, size 12, double-space

Citation Style: IEEE 

Length: 1–2 pages

Self-Assessment Checklist

I researched three specific tools that can aid in recovering deleted Macintosh files.

I described the capabilities of the tools.

I recommended one product for use in this case and justified my recommendation.

I created a professional, well-developed report with proper documentation, grammar, spelling, and punctuation.