o CISC 3115 — Lab #2

CISC 3115
Introduction to Modern Programming Techniques
Lab #02
Classes — Composition, Arrays & COntainers, Mutabilioty

How to Develop and Submit your Labs

Lab 1.3 Quadrilateral

Lab 1.3.1 — Quadrilateralsl Class (Quadrilateral) (Approval)

Model a quadirilateral (four sided figure) in 2-dimensional space (i.e., the 2D plane). Like the LinePair, a quadrilateral is represented as four pair of values, but here they represent the found corners of the figure, consisting of four lines: 
      (x1, y1) (point 1)             (x2, y2) (point 2)
	          ______________________ 
               \                    /
                \                  /
                 \________________/        
         (x4, y4) (point 4)         (x3, y3) (point 3)

(Note the order of the points; that is the order in which they are input)

The class should contain the following:

I've supplied the Line and Point classes (both as source and class files; you might want to experiment with your IDE in how to add .class files to your project.

Notes
  • a quadrilateral can be thought of as four points (the 'corners') or four lines (the sides). (There are other possibilities, but these two are the simplest). You thus have two 'natural' choices for instance variables:
    • four Points
    • four Lines
    For this exercise, I'm going to ask you to represent the quadrilateral as four Point objects (we discussed this in class).
  • Your constructor(s): Your constructor should consist of the four Points.
  • The app is printing out quadrant info, which comes from the Point class … you have that from your instance variables
  • The class' isRhombus amd isParallelogram methods require the length of the various sides, and length is a method of the Line class. You have a couple of options to get that from your four Point instance variables:
    • add four additional instance variables, side1 of type line, side2, etc (you can initialize them in the constructor together with the four Point instance variables (not recommended, don't need the Line objects as instance variables; it's redundant.
    • create the four sides (again, they're Line objects) in the above two method (i.e., when and where you need them).
    You can then call the length method on the sides under being looked at.
  • Note isParallelogram could also be defined by leveraging Line's slope method but would either fail, or require special logic for the case of vetical sides (which have undefined slope). (After you get your class working, you might want to try using slope instead; it may give you a chance to become a bit familiar with Java's NaN (not-a-number) value.)

    • Lab 1.3.2 — Quadrilateral App Class (QuadrilateralApp) (Approval)

    Code the app class for Lab 1.3.1

    quadrilateral.data 

    1 1   2 1   2 2   1 2	 
1 -1   1 1  -2 1  -2 -1 
0 0   1 0   1 1   0 2
    Sample Test Run

    Here is a sample execution of the program.
    User input is in bold. Your program should replicate the prompts and output:

    (1, 1) - (2, 1) / (2, 2) - (1, 2)
    (1, 1) Quadrant: Quadrant 1 (1)
    (2, 1) Quadrant: Quadrant 1 (1)
    (2, 2) Quadrant: Quadrant 1 (1)
    (1, 2) Quadrant: Quadrant 1 (1)
    Quadrilateral lies in one quadrant: true
    Rhombus

    (1, -1) - (1, 1) / (-2, 1) - (-2, -1)
    (1, -1) Quadrant: Quadrant 4 (4)
    (1, 1) Quadrant: Quadrant 1 (1)
    (-2, 1) Quadrant: Quadrant 2 (2)
    (-2, -1) Quadrant: Quadrant 3 (3)
    Quadrilateral lies in one quadrant: false
    Parallelogram

    (0, 0) - (1, 0) / (1, 1) - (0, 2)
    (0, 0) Quadrant: Origin (0)
    (1, 0) Quadrant: Positive x axis (5)
    (1, 1) Quadrant: Quadrant 1 (1)
    (0, 2) Quadrant: Positive y axis (6)
    Quadrilateral lies in one quadrant: false
    Simple quadrilateral

    stdout 

    (1, 1) - (2, 1) / (2, 2) - (1, 2)
(1, 1) Quadrant: Quadrant 1 (1)
(2, 1) Quadrant: Quadrant 1 (1)
(2, 2) Quadrant: Quadrant 1 (1)
(1, 2) Quadrant: Quadrant 1 (1)
Quadrilateral lies in one quadrant: true
Rhombus

(1, -1) - (1, 1) / (-2, 1) - (-2, -1)
(1, -1) Quadrant: Quadrant 4 (4)
(1, 1) Quadrant: Quadrant 1 (1)
(-2, 1) Quadrant: Quadrant 2 (2)
(-2, -1) Quadrant: Quadrant 3 (3)
Quadrilateral lies in one quadrant: false
Parallelogram

(0, 0) - (1, 0) / (1, 1) - (0, 2)
(0, 0) Quadrant: Origin (0)
(1, 0) Quadrant: Positive x axis (5)
(1, 1) Quadrant: Quadrant 1 (1)
(0, 2) Quadrant: Positive y axis (6)
Quadrilateral lies in one quadrant: false
Simple quadrilateral

    What's the Point of This Lab?

    Lab 2. — Phonebook (Phonebook) (Approval)

    Lab 2.2.1 — The Phonebook Class (Phonebook)

    Make the following changes to the Phonebook class of Lecture 2:

    Lab 2.2.2 — Phonebook App (PhonebookApp) (Approval)

    Write the app for Lab 2.2.1. (I've supplied the PhonebookEntry class source file as well the Phonebook file).
    • The format of the entries in the file should be: 
      last-name   first-name   phone-number
    • The lookup process now prompts for both a last and a first name
    • Since the user at the keyboard now has a choice of lookup (normal or reverse), we first prompt for the choice before entering the data used for the search.
    • Rather than continuing until the user signals end-of-file (at the keyboard) as in the lecture version, the user enters a 'q' as their choice to indicate they are done
    • After the user is done, the number of lookups and reverse lookups performed are printed
    • Finally, sort the array by last name / first name and write the results to the file sorted.text
    Remember, the search data is entered from the keyboard.

    stdin 

    l
Arnow
David
r
456-789-0123
l
Weiss
Jerrold
l
Weiss
Gerald
r 
111-123-4567
q

    phonebook.text 

    Arnow       David    123-456-7890
Harrow      Keith    234-567-8901
Jones       Jackie   345-678-9012
Augenstein  Moshe    456-789-0123
Sokol       Dina     567-890-1234
Tenenbaum   Aaron    678-901-2345
Weiss       Gerald   789-012-3456
Cox         Jim      890-123-4567
Langsam     Yedidyah 901-234-5678
Thurm       Joseph   012-345-6789
    Sample Test Run

    Here is a sample execution of the program.
    User input is in bold. Your program should replicate the prompts and output:

    lookup, reverse-lookup, quit (l/r/q)? l
    last name? Arnow
    firt name? David
    David Arnow's phone number is 123-456-7890

    lookup, reverse-lookup, quit (l/r/q)? r
    phone number (nnn-nnn-nnnn)? 456-789-0123
    456-789-0123 belongs to Augenstein, Moshe

    lookup, reverse-lookup, quit (l/r/q)? l
    last name? Weiss
    first name? Jerrold
    - - Name not found

    lookup, reverse-lookup, quit (l/r/q)? l
    last name? Weiss
    first name? Gerald
    Gerald Weiss's phone number is 789-012-3456

    lookup, reverse-lookup, quit (l/r/q)? r
    phone number (nnn-nnn-nnnn)? 111-123-4567
    -- Phone number not found

    lookup, reverse-lookup, quit (l/r/q)? q

    3 lookups performed
    2 reverse lookups performed

    stdout 

    lookup, reverse-lookup, quit (l/r/q)? last name? first name? David Arnow's phone number is 123-456-7890

lookup, reverse-lookup, quit (l/r/q)? phone number (nnn-nnn-nnnn)? 456-789-0123 belongs to Augenstein, Moshe

lookup, reverse-lookup, quit (l/r/q)? last name? first name? -- Name not found

lookup, reverse-lookup, quit (l/r/q)? last name? first name? Gerald Weiss's phone number is 789-012-3456

lookup, reverse-lookup, quit (l/r/q)? phone number (nnn-nnn-nnnn)? -- Phone number not found

lookup, reverse-lookup, quit (l/r/q)? 
3 lookups performed
2 reverse lookups performed
    sorted.text 
    Arnow David 123-456-7890
Augenstein Moshe 456-789-0123
Cox Jim 890-123-4567
Harrow Keith 234-567-8901
Jones Jackie 345-678-9012
Langsam Yedidyah 901-234-5678
Sokol Dina 567-890-1234
Tenenbaum Aaron 678-901-2345
Thurm Joseph 012-345-6789
Weiss Gerald 789-012-3456

    What's the Point of This Lab?
      • Like all the other apps in this, this one builds on the corresponding app in the lecture
      • Familiarizing yourself with these apps will make it easier for you to understand class implementations
      • This phone book app will be one of the app themes running through the semester
      • Sorting class objects

    Lab 2.3 — A Container

    Lab 2.3 — A Container (Container) (Approval)

    Starting with the Container class from Lecture 2:
    • Change the element type to String
    and add the following methods:
    • contains: similar to find except this method returns true/false instead of the position. You should assume the availability of find and NOT repeat the search logic. (See the note in explanation below).
    • set: this method accepts an index and value, and assigns the value to the location specified by the index. For example: 
      set(values, size, 10, 14);
      assigns 14 to location 10 in the array.

      set is the counterpart to get: the former returns the value at a location in the container; the latter assigns (overwrites) an element in the container.

    input file 

    A 	dog	
A 	cat
F 	cat
F 	cow
F 	dog
C	cat
C	cow
G	1
G	0
S	1	cow
F 	cow
F	cat
    Sample Test Run

    Here is a sample execution of the program.
    User input is in bold. Your program should replicate the prompts and output:

    After adding dog: {dog}
    After adding cat: {dog, cat}
    cat is at position 1 of the container
    cow is not in the container
    dog is at position 0 of the container
    cat is in the container
    cow is not in the container
    The value at location 1 is cat
    The value at location 0 is dog
    After setting position 1 to cow: {dog, cow}
    cow is at position 1 of the container
    cat is not in the container

    stdout 

    After adding dog: {dog}
After adding cat: {dog, cat}
cat is at position 1 of the container
cow is not in the container
dog is at position 0 of the container
cat is in the container
cow is not in the container
The value at location 1 is cat
The value at location 0 is dog
After setting position 1 to cow: {dog, cow}
cow is at position 1 of the container
cat is not in the container

    What's the Point of This Lab?
    • Practice making changes to someone else's existing class.
    • Introduce you to thinking about and coding delegation methods.
      • If you get completely stuck on writing contains using find (as opposed to recoding the search logic, or don't even understand what you're being asked to do, go look at my Lecture 12 (Techniques III) notes -- look for (Linear) Searching an Array; it shows you what I want. (But please give it some thought first.
        • The technique is called leveraging there; we'll dicuss these terms in more detail in class.

    Lab 2.3.2 — A Container Class App (ContainerApp))

    Write the app class for Lab 2.3.1

    What's the Point of This Lab?
    • There's a static (class) variable in this class (CAPACITY)
    • A slightly more involved toString
    • Leveraging find to get contains

    Labs 2.4 & 2.5 — Immutable and Mutable Classes

    What's the Point of This Lab?
    • Practice writing an immutable as well as a muable class.
    • Writing a pair class
    • Overloaded constructors, and in particular the this() construct in constructors.
    The integer classes implemented in this lab are for all practical purposes useless, the primitive int type provides the same operations, and in a much more intuitive fashion. We introduce them for several reasons:
    • they are the simplest sort of class that illustrate immutability and mutability.
    • they anticipate later classes (such as rational and complex numbers) that don't have primitive counterpart (and thus benefit from implementation as a class), and act as a good introduction for the implementation of such classes.

    • As before, each lab consists of an object class and a corresponding app class. Each lab is split into two exercise for the purposes of CodeLab; when developing it in your IDE, you will probably want both in the same project so that you can test the object with the app.
    • You can see the app output in the first exercise of each lab.

    Lab 2.4 Immutable Integer

    Lab 2.4.1 An Immutable Integer Class (ImmutableInt) (Approval)

    Write an immutable class, Immutable, modelling integers, with the following state/behavior:
    • Methods:
      • ImmutableInt add(ImmutableInt immutableInt)
      • ImmutableInt sub(ImmutableInt immutableInt)
      • ImmutableInt mul(ImmutableInt immutableInt)
      • ImmutableInt div(ImmutableInt immutableInt)
      • toString()
    • State:
      • An int instance variable maintaining the integer value of the object

    • Have an overloaded, 0-argument constructor that assigns 0 to the internal state variable. This constructor should leverage the 1-argument constructor *i.e., use the this(…) construct)
    • You can see the output below of the corresponding app class.
    • Assume 0 is never sent as the argument to div
    • The app consists of various declarations and creations of the objects, and calls to the methods; e.g.: 
      …
ImmutableInt i1 = new ImmutableInt(10);
System.out.println("i1: " + i1);
…
System.out.println("i1.add(i2): " + i1.add(i2);
…
      • Part of the challenge (i.e., 'fun') here is trying to reproduce my app (i.e., the declaration and creation of the reference variables and objects, and the various calls to the methods of the class. Please feel free to query me if you are having trouble doing so … I will be happy to give you hints

    stdout 

    i1: 10
i2: 20
i3: 0

i1.add(i2): 30
i1.sub(i2): -10
i1.mul(i2): 200
i1.div(i2): 0

i1: 10
i2: 20
i3: 0

    Lab 2.4.2 An App Class for 2.4.1 (ImmutableIntApp) (Approval)

    Write the app class for lab 2.4.1. The output should match the output as shown in that exercise.

    What's the Point of This Lab?
    • A fairly simple, baseline example of an immutable class

    Lab 2.5 Mutable Integer

    Lab 2.5.1 A Mutable Integer Class (MutableInt) (Approval)

    Write a Mutable class, MutableInt, modelling integers,with the following state/behavior:
    • Methods:
      • MutableInt increaseBy(MutableInt immutableInt)
      • MutableInt decreaseBy(MutableInt immutableInt)
      • MutableInt multiplyBy(MutableInt immutableInt)
      • MutableInt divideBy(MutableInt immutableInt)
      • MutableInt reset()
      • toString()
    • State:
      • An int instance variable maintaining the integer value of the object

    • Have an overloaded, 0-argument constructor that assigns 0 to the internal state variable. This constructor should leverage the 1-argument constructor *i.e., use the this(…) construct)
    • reset sets the internal state variable to 0
    • Again, the output of the corresponding app class is shown below.
    • Assume 0 is never sent as the argument to divideBy
    • The semantics of the method should be that the receiver is returned as the value of the method, allowing for operation chaining
    • As in the previous exercise, The app consists of various declarations and creations of the objects, and calls to the methods; e.g.: 
      …
MutableInt i0 = new MutableInt();
System.out.println("i0: " + i0);
…
System.out.println("i0.increaseBy(i1): " + i0.increaseBy(i1);
…
      • Again, part of the challenge (i.e., 'fun') here is trying to reproduce my app (i.e., the declaration and creation of the reference variables and objects, and the various calls to the methods of the class. Please feel free to query me if you are having trouble doing so … I will be happy to give you hints
        • I'm guessing this one is a bit more 'challenging'' then the previous, but once you get here, you'll have the experience of the first one, which should be a help.

    stdout 

    ===== Initial Values =====
i0: 0
i1: 10
i2: 5
i3: 20
i4: 25

i0.increaseBy(i1): 10
i0: 10
i1: 10
i2: 5
i3: 20
i4: 25

i0.decreaseBy(i2): 5
i0: 5
i1: 10
i2: 5
i3: 20
i4: 25

i0.multiplyBy(i3): 100
i0: 100
i1: 10
i2: 5
i3: 20
i4: 25

i0.divideBy(i4): 4
i0: 4
i1: 10
i2: 5
i3: 20
i4: 25

i0.reset(): 0
i0: 0

===== Chaining =====

i0.increaseBy(i1).decreaseBy(i2).multiplyBy(i3).divideBy(i4): 4
i0: 4
i1: 10
i2: 5
i3: 20
i4: 25

    Lab 2.5.2 An App Class for 2.5.1 (ImmutableIntApp) (Approval)

    Write the app class for lab 3.1.1/ The output should match the output as shown in that exercise.

    What's the Point of This Lab?
    • A fairly simple, baseline example of a mutable class