Exam 1

This page details a take-home exam that you will complete over the next few days. You can’t communicate with anyone about the content of the assignment until you receive your grade. The course staff will not give debugging advice or answer questions about the problems. If you have technical trouble creating a screencast (detailed below) feel free to reach out for assistance.

You can make use of any course notes, online resources, Java tools, and so on to complete the exam.

You will complete the programming task below and submit ExamplesSearch.java to the exam1 Gradescope assignment.

You will also submit a video screencast of yourself presenting a portion of it to this Google Form.

Submission checklist (see long descriptions below for full details):

  • [ ] Fields task1a and task1b in ExamplesSearch class
  • [ ] Three examples of testing task1b in ExamplesSearch class
  • [ ] AreaLessThan class
  • [ ] Two constructed AreaLessThan objects
  • [ ] Four total tests for AreaLessThan (two for each object)
  • [ ] EitherQuery class
  • [ ] Constructed EitherQuery object CHANGED – removed a comment about a required AndQuery here
  • [ ] Two tests using this constructed EitherQuery object
  • [ ] Screencast
    • Show ID
    • Trace evaluation of task1b test
    • Trace evaluation of EitherQuery test

Your submission will be graded after the deadline. The Gradescope upload will just check to make sure that there aren’t any errors reported by Java when we try to run your programs, not whether tests succeeded or failed. You should test thoroughly yourself to make sure your program works as expected.

Tasks

Download this starter code:

https://github.com/ucsd-cse11-s20/exam1

(This is very lightly adapted from this reading)

You should not change any of the existing methods or classes except for adding to ExamplesSearch. Don’t change ImageQuery or the other query classes, just add new ones as described below.

Task 1

  • Add a new field to the ExamplesSearch class called task1a of type ImageQuery. Its value should be a query that returns true on matches for images that have the extension "jpg".

  • Add a new field to ExamplesSearch called task1b of type ImageQuery. Its matches method should return true for images that have the keyword "ucsd" and do not have the keyword "ucsf" (false otherwise). Construct ImageData inputs matching these descriptions, and show how the query you constructed behaves when matching each of them:

    1. An image that has the keyword "ucsd" and not "ucsf"
    2. An image that has the keyword "ucsd" and has the keyword "ucsf"
    3. An image that does not have either "ucsd" or "ucsf" as a keyword

Task 2

Add a new type of query called AreaLessThan that represents a query that returns whether the area of an image (its width times its height) is less than an area provided to the query. It should implement ImageQuery.

Test the new class by creating two example AreaLessThan queries, and testing each on two inputs: one example that returns true and one that returns false. You can write these as fields in ExamplesSearch or as tester methods, your choice, but they must be clearly indicated as the tests for Task 2.

Task 3

Add a new type of query called EitherQuery that represents a combination of two queries that returns true if either one matches, but false if both or neither match. For example, for an EitherQuery combining a keyword search for "apple" and a keyword search for "banana":

  • It should return true when matching an ImageData with keywords "apple orange"
  • It should return true when matching an ImageData with keywords "fruit banana"
  • It should return false when matching an ImageData with keywords "apple orange banana"
  • It should return false when matching an ImageData with keywords "no fruit here"

Then, create an EitherQuery object. Demonstrate using this query’s matches method on two different ImageData inputs, once returning true and once returning false.

Task 4 – Video

You will record a short video of no more than 8 minutes. Include:

  • Your face and your student ID for a few seconds at the beginning. You don’t have to be on camera the whole time, though it’s fine if you are. Just a brief confirmation that it’s you creating the video/doing the work attached to the work itself is what we want.

  • For the second example from task1b – “An image that has the keyword "ucsd" and has the keyword "ucsf"”:

    Run the program and show the output corresponding to the method call for this example. Then, starting from the line in your code with the the call to the matches method, indicate each line of code that runs in your program while evaluating that method call. You can scroll to and click the lines to highlight them, or otherwise indicate each one. You should indicate them in the order that Java will evaluate them (this might be different than the order they *appear in the file).

  • For this task, repeat the process of running the program, showing the output, and indicating which lines run and in which order. This time, do it for one of the calls to the matches method of EitherQuery you created in Task 3.

An example of what your video should look like when doing this kind of explanation is here:

https://drive.google.com/open?id=1E-TcVXSg9BI4MnWoVU9_BbcRJsu8ZhCf

PA5 has a tutorial for creating a screencast like this https://ucsd-cse11-s20.github.io/pa5/.