Why this matters
- Classes and interfaces — detailed pointwise breakdown in the section below.
- Relationships — detailed pointwise breakdown in the section below.
- Multiplicity — detailed pointwise breakdown in the section below.
- What to skip — detailed pointwise breakdown in the section below.
- Whiteboard clarity often decides pass/fail before code depth.
ParkingLotentry facade
ParkingFloorcollection of spots
Ticketissued on entry
Vehiclecar, bike, truck
ParkingSpot links Vehicle when occupied; Strategy picks spot by vehicle type.
Overview
The notation you actually need on a whiteboard — nothing more. Study each section below in order — every list is interview-ready reference material.
Classes and interfaces
Points to cover
- Definition — what Classes and interfaces means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
Relationships
Points to cover
- Definition — what Relationships means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
Multiplicity
Points to cover
- Definition — what Multiplicity means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
What to skip
Points to cover
- Definition — what What to skip means in one clear sentence
- When to use — the force or smell that triggers this concept
- CampusOS example — where this appears in parking, booking, or library modules
- How to explain — pointwise bullets you can say aloud in an interview
- Common mistake — what weak candidates do instead
- Refactor move — one concrete change that improves the design
// CampusOS — apply "Classes and interfaces" on paper first, then in code
public final class UmlClassDiagramsExample {
// 1. Name entities from the problem statement
// 2. Draw relationships before writing methods
// 3. Introduce patterns only when a force appears
}
Quick recall
Everything you need if you only revisit this box.
- Classes and interfaces — review this slice before mock interviews.
- Relationships — review this slice before mock interviews.
- Multiplicity — review this slice before mock interviews.
- What to skip — review this slice before mock interviews.
Test yourself
Answer these before moving on — recall is what makes it stick.