Eboard 06: Building classes and objects, continued
You are probably being recorded, perhaps even transcribed. Of course, the technology failed in my earlier class, so perhaps not.
Approximate overview
- Administrivia
- Questions
- Lab
Preliminaries
- I hope that VSCode and GitHub are now working better for many of you.
I helped everyone who visited yesterday.
- As you’ve probably learned, I believe in adapting the class and the
schedule to what I observe. If you find yourself confused by a topic,
ask and I’ll usually spend time on it.
- But don’t do so just to slow down the course.
- Today’s distraction: Remember that GitHub and Copilot normally use
your prompts as training data unless you stop them from doing so.
- In GitHub, there’s a “don’t record” setting. It also stops
your history.
- It looks like Grinnell’s license with Microsoft ensures that
Copilot does not record. Yay!
- My office hours are now posted.
- If I don’t respond to email within 24 hours, I’ve probably lost it or
forgotten about it, so email again.
Upcoming work
- Tonight at 11:00 pm Mini-project 1 post-reflection
- Friday at 11pm: Mini-project 2 pre-reflection
- Sunday at 11pm: Readings
- Monday at 1pm: Today’s lab
- Next Wednesday: Mini Project 2
Tokens
Academic/Scholarly
Cultural
Peer
- Tennis, Sunday, 9 and 4pm, Field house,
Matches against Augustana
- Swim meet this weekend. Saturday 1pm in the Natatorium against Augusta.
- GameDev works-in-progress expo, Saturday, 2-4pm in a room in the HSSC.
One of the games is “Can you find the room?” (N2110)
Wellness
Misc
- Friday, 2024-02-02, 8pm, Harris Concert Hall:
Weekend Murder Mystery.
- InfoSec survey (stay tuned for email)
Good things to do (no tokens)
Friday PSA
- Please take of yourselves and those around.
- Please be moderate.
- Please do not try to mimic what you believe others do; choose what is
right for you.
- Consent is essential.
Questions
Administrative
MP2
Do we have to handle order of operations?
There is no precedence; you should evaluate operations from left to
right. There may be an arbitrary number of values and operations on
each line.
Do we have to use Git for this mini-project?
No. But this is a good project to expand as a sample of your awesome
coding abilities.
Can there be multiple operations of different types in the same expression?
Yes, you can expect 1/2 * 3/4 - 2/3 or a * 1/2 - b * 1/2.
But it’s still left-to-right
Should we support parentheses?
There will not be parentheses in the input.
If you decide to expand the capabilities, that would be great.
Miscellaneous
Do we have to use Git/GitHub in the future?
Yes. And I expect that you do regular commits, too.
Can I see our class on GitHub?
Probably. I tend to be a believer in openness.
Lab
Preliminaries
Let’s hope that everyone can finish!
Make sure to work on the big workstation, not on your individual laptop.
(I suppose LiveShare is fine.)
Things we might be learning
- As we get started, it often feels like we’re missing a parameter. That’s
because there’s always an implicit “this” that’s doing the work.
- I find it useful to think of method calls as telling objects to do things.
- “Hey, 1/2, multiply yourself by 1/3”
- It’s important to read the documentation (e.g., to figure out how to
convert strings to
BigInteger values).
- Clean coding: Put your experiments and tests in a separate file from
your utility code.
- Pay attention to special cases.
- When you create a new objects, you generally need to call
new Type(params).
- The Java libraries are woefully inconsistent.
- Convert a string to an
int: Integer.parseInt(str).
- Convert a string to an
Integer: Integer.valueOf(str).
- Convert a string to a
BigInteger: new BigInteger(str).
- Sam is more excessive on these things than most faculty.
The wonderful Fraction(String str) constructor
What happens when you create the following fractions?
f5 = new Fraction("2147483649/2");
f6 = new Fraction("42");
f7 = new Fraction("9223372036854775808/3");
What to submit
I prefer that you submit Fraction.java and Counter.java.