En anglais

Give every class one clear job

Computing · Programming · ages 16-18

Name ______________________ Date ____________

Member owns contact details and must keep them valid. Which responsibility belongs with that data?
- Change a book's repair status when its cover tears
- Set loan dates from a library-wide lending policy
- Check and update the member's contact details
A cinema stores screenings, customer details and bookings linking a customer to a screening. Which set models these three record kinds?
- Screening, Customer and Booking
- Screening, Booking and SeatNumber
- Customer, Booking and ScreenWidth
Account has deposit and withdraw methods that maintain its balance. Having these two related actions does not by itself mean the class should split.
Circle one: True False
A Library class maintains catalog records and fee rules. A catalog team changes book details; a finance team changes fee policy independently. Which boundary follows those responsibilities?
- Keep both together because they serve the same library
- Separate catalog records from the changing fee policy
- Move both jobs into one shared class-level dictionary
Loan creates and updates the dates for one borrowing relationship. Book maintains bibliographic details. Where should that loan's due date be maintained?
- Loan, which owns and updates that loan's dates
- Book, which copies every loan's current due date
- Both, with separately edited copies of the due date
Catalog and FeePolicy have been separated. Catalog needs a fee calculation. How should the design preserve separate ownership while letting them cooperate?
- Copy the fee rules into Catalog so both classes can edit them
- Move all fields into FeePolicy so Catalog owns no records
- Keep separate owners and use a defined request for the fee
One class maintains member signup records and book-repair records. Their rules change independently. A split is chosen. Which change carries out that split?
- Keep both jobs together and rename the class Coordinator
- Separate signup state and methods from repair state and methods
- Keep both jobs together and move their methods into __init__
Member maintains and validates postal addresses. Checkout reads one to print a label. A designer wants Book to keep another editable address copy. Which boundary is justified?
- Book owns the address because checkout prints the label
- Member owns it; checkout requests it when needed
- Member and Book each maintain their own address copy

Answer key

For grown-ups. Fold this page away before handing over the rest.

Give every class one clear job W1-mt_De_gpvpOzg-s1

Check and update the member's contact details · Checking and updating the contact details serves Member's stated maintenance responsibility.
Screening, Customer and Booking · The requirements identify screenings, customers and their booking relationships. Seat numbers and screen width are not the three described record kinds.
True · Both actions serve the same balance responsibility. Counting verbs or using and does not establish unrelated jobs.
Separate catalog records from the changing fee policy · The two responsibilities have separate rules and independent reasons to change, which supports a boundary between them.
Loan, which owns and updates that loan's dates · The due date describes the borrowing relationship whose dates Loan maintains.
Keep separate owners and use a defined request for the fee · Catalog can request a calculation from FeePolicy without owning another editable copy of its rules.
Separate signup state and methods from repair state and methods · A split moves each responsibility's state and maintaining methods together, then defines how the new owners cooperate.
Member owns it; checkout requests it when needed · Member has the stated maintenance and validation duty. Checkout's read does not justify a second editable owner.