Eboard 09: Subtype polymorphism

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
• Discussion of MP3

Preliminaries

• We have class 9 on the 9th. Yay!
• There are many sick people on campus. Consider masking.
• Feel free to send me questions on Teams, even at night. If I’m available, I’ll answer them quickly. If not, I’ll try to answer them the next day.
• If you are unable to visit class in person, it’s fine to attempt to visit on Teams. (Please try to make it to class if you can.)
• Our evening tutors are likely to be busy on nights when HW is due (Wednesday) and the night before (Tuesday), so starting earlier can help.
• Don’t forget to say your name when you ask a question.

Upcoming work

• 11pm Friday, 2024-02-09: Mini-Project 2 post-reflections
  • Submit on Gradescope
• 11pm Friday, 2024-02-09: Mini-Project 3 pre-reflections
• 11pm Sunday, 2024-02-11: Reading Reflections
  • Java generics
  • Submit on Gradescope
• 11pm Wednesday, 2024-02-14: Mini Project 3
  • Submit on Gradescope
• No lab writeup from today’s class

Tokens

Academic/Scholarly

• Tuesday, 2024-02-13, noon-1:00pm. Some PDR. CS Table: Functional programming.
• Tuesday, 2024-02-13, 8:00-9:00pm. Science 3821. CSC-207 Mentor Session.

Cultural

• Master class 4pm
• Friday, 2024-02-09, 5:30pm, Sebring-Lewis Concert

Peer

• Friday, 2024-09-09, 4-5pm, HSSC N1170 - Global Living Room. Middle of Everywhere.
• Friday, 2024-02-09, 7-9pm, Harris Center. Celebration of New Year.
• Saturday, 2024-02-10, 10am–1pm, Field House. Darren Young Classic.

Wellness

• Saturday, 2024-02-10, 7-10 pm, HSSC. Buzzer Dating Experience.

Misc

• Saturday, 2024-02-10, 8:00-11:00pm, Harris Multi-Purpose Disco Room. Roller Skating.
• Monday, 2024-02-12, 4:30-5:30pm, JRC 101. Talking about disability policy with Daniel Van Sant, Director of disability policy at the Harkin Institute.

Good things to do (no tokens)

Friday PSA

• Roller skating while drunk is dangerous.
• Please take care of yourselves.
• Be moderation.
• Consent is essential.

Questions

Administrative

When will we get mini-projects back?

Soon.

Subtype polymorphism and interfaces

How does typecasting work in Java?

That’s a topic for another day.

Lab

Reminders

• Not everyone likes to work at separate computers. Make sure your partner is okay with it.

Notes

• double vs Double
  • double is a primitive type. Four bytes, IEEE representation.
  • Double is an object that wraps up a double and provides the various operations we’d expect for an object, such as toString and hashCode.

Do not submit.

Discussion of MP3

An extension of today’s lab.