Lab2 (Nested) Selections/Conditions

EECS1022 (M,N,O) 
Lab2
(Nested) Selections/Conditions

• You are required to work on your own for this lab. No group partners are allowed.

• Your lab assignment is not graded during the weekly scheduled lab sessions.
• Follow the instructions to submit (via eClass) the required file(s) for grading.
Emailing your solutions to the instructor or TAs will not be acceptable.
• Texts in blue are hyperlinks to the corresponding documents/recordings.

Contents
1 Task 1: Complete Weekly Java Tutorial Videos 4
2 Task 2: Complete Programming Exercises 5
2.1 Step 1: Download and Import the Starter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Step 2: Programming Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.1 Method to Implement: getRPSGameReport . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.2 Method to Implement: getTaxReport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Step 3: Exporting the Completed Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Submission 11
4 Amendments 12
Learning Outcomes
By completing the assigned exercises of this lab, you are expected to be able to:
1. Exercise a simple workflow of Github.
2. In the Eclipse IDE (Integrated Development Environment):
• Import a starter project archive file.
• Given a computational problem, develop a Java solution (i.e., a utility method) composed of:
– Numerical Literals and operators
– String Literals and operators
– Variables and assignments
– (Nested) Selections/Conditionals/If-Statements
• Run a Java class with with the main method as a console Java application.
• Use the given JUnit tests (calling the utility methods) to guide the development.
• Use the debugger features (step over/into/out/return) to find defects in programs.
• Export an existing project as an archive file.
3. Understand the separation of concerns (using packages): model, console apps, and junit tests.
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Assumptions
• You have already setup a Github account and stored work in a private repository: EECS1022-W21-workspace.
Note. You only submit your lab through eClass, not Github. Though not required, it is highly recommended
that you adapt to the practice of backing your work using a versioning tool like Github.
• You are able to use Eclipse to complete the tutorial videos and this lab assignment on either your own machine
or the EECS remote labs.
Note. The starter project was created using Eclipse and an Eclipse project archive file is expected to be
submitted. Therefore, you may not want to use other IDE such as IntelliJ.
Requirements of this Lab
• The grading of your lab will start by automatically unzipping the submitted Java project archive file (.zip)
and extracting the required class(es). It is therefore crucial for you to follow precisely the spelling of the
archive file name. Penalty will be taken if the grading cannot proceed due to carelessness on following the
instructions in Section 2.3.
• Your lab submission will only be graded using JUnit (for this lab, only the tests supplied to you). That is,
your lab submission will not be graded manually using the console application given to you.
• Do not modify the JUnit test class TestUtilities.java given to you.
• Do not modify the console application class (in package console apps) given to you.
• For each utility method in the Utilities class that you are assigned to implement, as discussed in Part F
of Week 1’s Java tutorial videos:
– No System.out.println statements should appear in each of the utility method.
Instead, an explicit, final return statement is placed for you.
– No Scanner operations (e.g., input.nextInt()) should appear in each of the utility method.
Instead, refer to the input parameters of the method.
• To complete this lab, it is not necessary to use loops or methods from library classes (e.g., Math).
• You are welcome to ask questions related to this lab or the assigned tutorial videos on the forum. However,
please be cautious:
– You can help your fellow students understand the requirements of tasks.
– Do not share the code you developed to ask, or to answer, questions.
∗ Questions specific to the code you write would be best and most effectively addressed by TAs (during
scheduled labs) or your instructor (during office hours or appointments).
∗ Week 3’s tutorial videos (Parts C to E) introduce to you debugger in Eclipse. You are encouraged
to set breakpoints and launch the debugger when you are stuck at your own program.
– Hints on how the solution should look like are left only to the instructors who moderate the forum.
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1 Task 1: Complete Weekly Java Tutorial Videos
• For Lab2, you are assigned to study Week 3 Part A to Part G of the Java tutorial series:
https://www.youtube.com/playlist?list=PL5dxAmCmjv_6UHGyyTZTNorPaBgcXpauf [ Week 3 only ]
To reference tutorial videos from the previous weeks, see:
https://www.youtube.com/playlist?list=PL5dxAmCmjv_6wy2m0yq2wObIWPz4tAxW6 [ All Weeks ]
These Java tutorial videos assigned to you are meant for you to:
1. Obtain extra hands-on programming experience on Java, supplementing your weekly lectures.
2. Complete the lab assignment with the necessary skills and background.
Parts A to G are directly relevant to this lab. Parts F and G from Week 2 are also relevant to your
Lab2.
Though we do not require the submission of the weekly Java tutorial project (like in Lab0), examples and
insights discussed in these tutorials will be covered in your (written and programming) tests
and exam: should you decide to skip the weekly tutorial videos, it would be your choice.
As you study through the example Java classes in the tutorial videos, you are advised to type them out
(but absolutely feel free to add new Java classes to experiment) on Eclipse.
• You can find the iPad notes of illustrations from the tutorial videos here:
https://www.eecs.yorku.ca/˜jackie/teaching/tutorials/notes/EECS1022%20Tutorial%20on%20Java.pdf
• This week’s Java tutorial shows some example of nested if-statement. Optionally, if you wish to study more
about nested if-statement, refer to these two videos:
– A simple bank application: Nested If-Statements Version 1:
https://www.youtube.com/watch?v=w3YojTfDTeA&list=PL5dxAmCmjv_5NRNPG3OiWZWAqmvCjiLfG&index=19
– A simple bank application: Nested If-Statements Version 2:
https://www.youtube.com/watch?v=FI0d8XKBymg&list=PL5dxAmCmjv_5NRNPG3OiWZWAqmvCjiLfG&index=20
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2 Task 2: Complete Programming Exercises
Starting Task 2 should mean that you have already completed the weekly Java tutorial videos (Section 1).
2.1 Step 1: Download and Import the Starter Project
1. Download the Eclipse Java project archive file from eClass: EECS1022 W21 Lab2.zip
2. Launch Eclipse and browse to EECS1022-W21-workspace as the Workspace then click on Launch, e.g.,
3. In Eclipse:
3.1 Choose File, then Import. 3.2 Under General, choose Existing Projects into Workspace.
3.3 Choose Select archive file. Make sure that the EECS1022 W21 Lab2 box is checked under Projects.
Then Finish.
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2.2 Step 2: Programming Tasks
From the Package Explorer of Eclipse, your imported project has the following structure.
• You can manually test the assigned methods using the corresponding console application classes in package
console apps. These classes are completed and given to you. See below for more descriptions.
• Your goal is to pass all JUnit tests given to you (i.e., a green bar). To run them, as shown in the Java
tutorials on Week 1, right click on TestUtilities.java and run it as JUnit tests. Of course, none of the
given tests would pass to begin with.
You must not modify these given JUnit tests.
How to Deal with a Failed JUnit Test? From the JUnit panel from Eclipse, click on the failed test, then
double click on the first line underneath Failure Trace, then you can see the expected value versus the return
value from your utility method.
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2.2.1 Method to Implement: getRPSGameReport
Problem. You are asked to consider the rock-paper-scissors (RPS) game (for which it is assumed that you know
how to play it). Rock is denoted by character ’R’, paper by ’P’, and scissors by ’S’. As a reminder: rock wins
scissors, paper wins rock, and scissors wins paper.
Testing. Your goal is to pass all tests related to this method in the JUnit test class TestUtilities. These tests
document the expected values on various cases: study them while developing your code. However,
use the console application class RPSGameApp if you wish (e.g., use the input and expected values from the JUnit
tests).
Let’s consider two example runs (where the same two players swap the order from one game to another):
• Enter the name of player 1:
Doraemon
Enter the name of player 2:
Edward Scissorhands
What does Doraemon play at round 1 (R, P, S)?
R
What does Edward Scissorhands play at round 1 (R, P, S)?
S
What does Doraemon play at round 2 (R, P, S)?
R
What does Edward Scissorhands play at round 2 (R, P, S)?
S
Game over: Doraemon wins! [Round 1: Doraemon wins (R vs. S) ; Round 2: Doraemon wins (R vs. S)]
• Enter the name of player 1:
Edward Scissorhands
Enter the name of player 2:
Doraemon
What does Edward Scissorhands play at round 1 (R, P, S)?
S
What does Doraemon play at round 1 (R, P, S)?
R
What does Edward Scissorhands play at round 2 (R, P, S)?
S
What does Doraemon play at round 2 (R, P, S)?
R
Game over: Doraemon wins! [Round 1: Doraemon wins (R vs. S) ; Round 2: Doraemon wins (R vs. S)]
In this 2nd example run:
– The Round 1 result shows: Round 1: Doraemon wins (R vs. S).
– More precisely, R vs. S shows that rock wins scissors, despite the order of the players.
– That is, the left-hand side of vs. always shows the play that wins, not what player 1 (in this
case Edward Scissorhands) plays.
– A similar argument also applies to the Round 2 result.
Todo. Implement the Utilities.getRPSGameReport method. See the comments there for the input parameters
and requirements. The String return value must conform to the expected format (otherwise your code will fail
some JUnit tests). Here are some hints for you:
• Read carefully the comments in the Utilitye class about what each input of method getRPSGameReport
means. For example, invoking
Utilities.getRPSGameReport("Suyeon", "Yuna", ’R’, ’P’, ’S’, ’R’)
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means: Suyeon is player 1, Yuna is player 2, player 1 plays rock and player 2 plays paper in Round 1, and
player 1 plays scissors and player 2 plays rock in Round 2.
• Do not modify the console application class RPSGameApp given to you: the string return value of the utility
method getRPSGameReport must be a string like:
Game over: Doraemon wins! [Round 1: Doraemon wins (R vs. S) ; Round 2: Doraemon wins (R vs. S)]
• As illustrated in the above 2nd example run, the left-hand side of vs. always shows the play that
wins, not what player 1 plays.
• Be mindful about the spellings (e.g., Game over, wins): they are case-sensitive.
• Be mindful about the single spaces between words and after symbols such as :, !, ., and :.
• After the phrase ‘‘Game over:’’ comes the game result: it only shows who wins.
• Within the pair of square brackets [] comes the results of each round: it only declares who wins.
Hint. Study the 9 test cases in TestUtilites: they are arranged in a systematic (yet not complete) way.
Question. In order to exhaustively test this game, considering just how two players say Suyeon and Yuna
may play in the two rounds, how many tests do we need? (Optionally, you may write extra test yourself as
an exercise.)
2.2.2 Method to Implement: getTaxReport
After reading the problem description below, here is an illustration on the two example filers Jim and Jonathan:
https://www.youtube.com/watch?v=q2NT5x77hdg&list=PL5dxAmCmjv_7YgI2LgcwjWTHiNZSR-aQX&index=1.
Problem. You are asked to consider an imaginary income tax scheme, where the calculation is based on:
1. filing status (single filing or married filing)
2. taxable income
Once the above information is given by the user, the tax is calculated based on the following scheme:
Tax Rate Single Filing Status Married Filing Status
10% $0 – $8,350 $0 – $16,700
15% $8,351 – $33,950 $16,701 – $67,900
25% $33,950+ $67,900+
That is, a tax payer’s income is split into up to three parts, depending on how high their income is. Once split,
each part of the income is taxed with the corresponding rate. For a single filer, the cutoff points are $8,350 and
$33,950. For a married filer, the cutoff points are $16,700 and $67,900.
As an example, consider Jim who is a single filer and whose income is $186,476. Since his income is higher than
the second cutoff point for a single filer (i.e., $33,950), his income will be split into 3 parts:
• The first $8,350 is taxed with a rate of 10%.
• The subsequent $(33,950 - 8,350) is taxed with a rate of 15%.
• The final $(186,476 - 33,950) is taxed with a rate of 25%.
Important Exercise Before You Proceed: Try the tax calculation for Jonathan, who is a married filer and
who has a lower income $33,500. How would his income be split with this lower income? How would his income
tax then be calculated?
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Testing. Your goal is to pass all tests related to this method in the JUnit test class TestUtilities. These tests
document the expected values on various cases: study them while developing your code. However,
use the console application class TaxComputationApp if you wish (e.g., use the input and expected values from the
JUnit tests). Here are two example runs:
1. Enter your name:
Alan
Alan, enter your filing status (1 -- Single Filing; 2 -- Married Filing):
1
Alan, enter your taxable income (an integer value):
186476
Single Filing: $42806.50 (Part I: $835.00, Part II: $3840.00, Part III: $38131.50)
2. Enter your name:
Mark
Mark, enter your filing status (1 -- Single Filing; 2 -- Married Filing):
2
Mark, enter your taxable income (an integer value):
33500
Married Filing: $4190.00 (Part I: $1670.00, Part II: $2520.00)
Todo. Implement the Utilities.getTaxReport method. See the comments there for the input parameters and
requirements. The String return value must conform to the expected format:
• Do not modify the console application class TaxComputationApp given to you: the string return value of the
utility method getTaxReport must be a string like:
Married Filing: $4190.00 (Part I: $1670.00, Part II: $2520.00)
• If an income is split into less than 3 parts, the missing part(s) will not be included in the string report.
• You should first calculate the part(s) of tax of a given income, then calculate its sum, and then you must
format each part and the sum as floating-point numbers with exactly two digits following the decimal point
(e.g., 800.00, 789.10).
Hint. Use String.format(%.2f, someNumber) as shown in Week 1’s Java tutorials for this purpose.
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2.3 Step 3: Exporting the Completed Project
You are required to submit a Java project archive file (.zip) consisting all subfolders.
In Eclipse:
1. Right click on project EECS1022 W21 Lab2. 2. Under General, choose Archive File.
Then click Export
3. Check the top-level EECS1022 W21 Lab2
Make sure that all subfolders are checked: .settings, bin, and src.
Under To archive file: browse to, e.g., desktop, and save it as EECS1022 W21 Lab2.zip (case-sensitive)
Then Finish.
Note. In case you have concerns about exporting and submitting the .setting subfolder: it will be kept
confidential and access-protected on eClass.
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3 Submission
1. Before you submit, you must make sure that the Problems panel on your Eclipse shows no errors (warnings
are acceptable). In case you do not see the Problems panel: click on Window, then Show View, then Problems.
Submitting programs with errors (meaning that it cannot be run for grading) will result in
possible partial, but low, marks.
2. Section 2.3 asks you to export the Java project as an archive file:
EECS1022 W21 Lab2.zip
Before you submit, verify that its unzipped version has the following structure:
Figure 1: Lab2 Expected Project Structure
3. Go to the eClass site for Sections M,N,O: https://eclass.yorku.ca/eclass/course/view.php?id=6214
4. Under the Lab Submissions section, click on Lab2 to submit the Java archive file: EECS1022 W21 Lab2.zip
• You may upload as many draft versions as you like before the deadline.
• You must explicitly submit the draft version for grading before the deadline.
• Once you click on the submit button, you can no longer upload another draft version.
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4 Amendments
Clarifications or corrections will be added to this section.
•
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