You're building a parking garage app for a busy mall. The garage has 3 floors with 500 spots total. Cars, motorcycles, and trucks all need parking — but they take different amounts of space. You need a clean class design to represent vehicles.

Code

// Option A: Single class with type field
class Vehicle {
  type: 'car' | 'motorcycle' | 'truck'
  licensePlate: string
  spotsNeeded: number
}

// Option B: Abstract base + concrete subclasses
abstract class Vehicle {
  abstract spotsNeeded: number
  licensePlate: string
}
class Car extends Vehicle { spotsNeeded = 1 }
class Motorcycle extends Vehicle { spotsNeeded = 1 }
class Truck extends Vehicle { spotsNeeded = 2 }

Question

Which approach best models the vehicle types?

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Design Parking Lot

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Vehicle Class Hierarchy

Inheritance & Polymorphism

Code

// Option A: Single class with type field
class Vehicle {
  type: 'car' | 'motorcycle' | 'truck'
  licensePlate: string
  spotsNeeded: number
}

// Option B: Abstract base + concrete subclasses
abstract class Vehicle {
  abstract spotsNeeded: number
  licensePlate: string
}
class Car extends Vehicle { spotsNeeded = 1 }
class Motorcycle extends Vehicle { spotsNeeded = 1 }
class Truck extends Vehicle { spotsNeeded = 2 }

Question

Which approach best models the vehicle types?