The LAST Recitation

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The LAST Recitation

• Godfrey Tan

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Only a few things left to do in this class!

• Quiz 2 Review Sunday
• Quiz 2 Wednesday April 10
• Project
• TA assignments and scheduled weekly meetings
  (coming up soon)
• Spec coming out by Friday night

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Go home and get some sleep

• See ya!

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PS 6 Review
LoadButton(JFrame f) // Creates a new instance
of Load Button void actions(JFrame f) //
requires f instanceof JFrame // effects
Adds an action to create // a
LoadFrame when this // button is
clicked.
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PS 6 Review
public void actionPerformed(ActionEvent e) //
modifies this, tracker representation //
effects traps toolbar button clicks //
traps clicks on the toolbar button // and
dispatches methods accordingly. // updates
the UI where necessary. // Signals the
FolioRunner class to // spawn/destroy folio
windows as // necessary. // sets the
modified flag if the tracker // is modified.
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Questions

• Changes made to PS5?
• Turned in PS5 code?
• Gizmoball or Anitchess?
• Does 6.170 meet your expectations?

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Decentralized Organization

• Jointly make key decisions
• e.g. spec and Java interfaces
• Checkpoint meetings with a leader and an agenda
• e.g. resolve problems, track progress, code review

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Preliminary Design

• Specify requirements, design document
• Schedule work, sleep
• Say NO to caffeine
• Divide up the work into well-defined parts
• Use Java interfaces!!!
• Plan to redistribute work when something bad
  happens
• Backup often!
• Use CVS (6.170/www/info/tools.html)

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What you should have

• Turn vague requirements in project handout into a
  concrete requirement list
• Design overview and rationale
• Flexibility is important plan for your project
  amendments!
• Explain your ADTs and the algorithms you plan to
  use
• MDD of main modules
• Partial specifications of all public methods in
  each module. Complete spec for final report.

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What you should have

• Validation strategy e.g.
• chkRepInv() at beginning and end of public
  methods
• Costly checks should be done in unit tests
• checked vs unchecked Exceptions
• Messages should explain why exception was thrown
• Use abstraction function when a class is
  implemented by more than one person
• Use stubs/state machines

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Incremental Model

• Design and redesign
• Implement
• Validate (Unit Test and Integration)
• Go back to 1
• Start with depth-first implementation of basic
  functionalities, then add more complex ones.

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Development Stage

• Choose common platform and environment
• Athena, Forte, etc.
• Stick to the API specified in the design stage
• Document your amendments (what and why)
• Inform your partner of any major changes
  immediately
• Unit testing
• Code review
• Integration testing

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When program crashes

• Find the bug keep in mind that there could be
  more than one bug
• Do NOT point fingers especially when bugs are
  found during integration testing
• Its teamwork help fix the bugs
• Help each other LEARN

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Debugging

• Reproduce the bug
• Form hypotheses and try to isolate the code that
  has the bug
• Use binary search to pin-point the bug
• Be optimistic that you will eventually find the
  bug
• Ask help from your partner and eventually your TA
• Remember to take frequent snapshots of your
  project so you can roll back when all else fails!

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When schedule slips

• Isolate the problem
• Find ways to adjust the rest of the schedule by
• cutting features or sleep
• Tell your TAs about un-cooperative partners
• But keep in mind, your partners are all youve
  got

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Final words

• Remember- your goal is to build the software that
  works
• Everything you have learned in 6.170 is to help
  you achieve that
• Best way to learn programming is by programming
• When you are getting better at it, you receive
  more satisfaction and might actually enjoy being
  a programmer/engineer

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Good luck!

• May the force be with you!