4: Object-oriented programming

Question 1

Classes have a special method that serves as a blueprint for creating objects of that class. What is the method called?

• A builder

• An instantiator

• A constructor

• A blueprint

Question 2

Which of the following statements about interfaces and abstract classes is NOT correct?

• Abstract classes can have constructors.

• Interfaces can't have constructors.

• Interfaces and abstract classes can be instantiated directly.

• Abstract properties must be implemented by subclasses of the abstract class.

Question 3

Which of the following is NOT a Kotlin visibility modifier for properties, methods, etc.?

• internal

• nosubclass

• protected

• private

Question 4

Consider this data class:

data class Fish(val name: String, val species:String, val colors:String)

Which of the following is NOT valid code to create and destructure a Fish object?

• val (name1, species1, colors1) = Fish("Pat", "Plecostomus", "gold")

• val (name2, _, colors2) = Fish("Bitey", "shark", "gray")

• val (name3, species3, _) = Fish("Amy", "angelfish", "blue and black stripes")

• val (name4, species4, colors4) = Fish("Harry", "halibut")

Question 5

Let's say you own a zoo with lots of animals that all need to be taken care of. Which of the following would NOT be part of implementing caretaking?

• An interface for different types of foods animals eat.

• An abstract Caretaker class from which you can create different types of caretakers.

• An interface for giving clean water to an animal.

• A data class for an entry in a feeding schedule.