CodeSignal Technical Assessment Object-Oriented Programming

Question 1

What is encapsulation in object-oriented programming?

Accepted Answer

Bundling data and methods within a class while restricting direct access to internal state

Answer

The ability of a class to inherit properties from another class

Answer

Defining multiple methods with the same name in a class

Answer

Creating objects from abstract blueprints

Question 2

Which keyword is used in Java, C++, and JavaScript to create a new instance of a class?

Accepted Answer

new

Answer

create

Answer

instance

Answer

init

Question 3

What is inheritance in object-oriented programming?

Accepted Answer

A mechanism where one class acquires the properties and methods of another class

Answer

The process of hiding internal implementation details from users

Answer

The ability to define multiple methods with the same name

Answer

The conversion of one data type to another at runtime

Question 4

What is a constructor in OOP?

Accepted Answer

A special method automatically called when a new object is created

Answer

A method that destroys an object and frees its memory

Answer

A method that converts an object to its string representation

Answer

A static method that belongs to the class rather than its instances

Question 5

What does the `this` keyword (or `self` in Python) refer to inside an instance method?

Accepted Answer

The current instance of the class on which the method is called

Answer

The parent class of the current class

Answer

The class itself in a static context

Answer

The return value produced by the method

Question 6

Which OOP principle means different objects can respond to the same method call in their own specific way?

Accepted Answer

Polymorphism

Answer

Encapsulation

Answer

Abstraction

Answer

Composition

Question 7

Which of the following best describes an abstract class?

Accepted Answer

A class that cannot be instantiated directly and may contain abstract methods subclasses must implement

Answer

A class that contains only static methods and no instance methods

Answer

A class with no fields, only method signatures

Answer

A class that inherits from two or more parent classes simultaneously