Can abstract classes have constructors?

Short answer: Yes, abstract classes can have constructors. Used to initialize fields for derived classes. abstract class Vehicle {

Example code

public string Brand;
public Vehicle(string brand) { Brand = brand; }
}
class Car : Vehicle
{
public Car(string brand) : base(brand) { }
}

Real-world example (ShopNest)

Checkout calls IPaymentGateway.Charge(). Razorpay and Stripe adapters implement the same interface, so ShopNest can switch gateways without rewriting the order service.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.