Foundations

Question 1

What does OOP stand for?

Answer 1

Object-Oriented Programming

Question 2

How does OOP organize code?

Answer 2

By using objects that combine data (properties) and actions (methods).

Question 3

What are the four pillars of OOP?

Answer 3

Encapsulation, Abstraction, Inheritance, Polymorphism

Question 4

What is Encapsulation?

Answer 4

Bundles data (properties) and methods that operate on it within an object.
Like a coffee maker - protects internal workings (water level) and controls access (setter methods).

Question 5

What is Abstraction?

Answer 5

Hides complex details and shows essential functionalities. Like a TV - use turnOn without knowing how the image is displayed.

Question 6

What is Inheritance?

Answer 6

Reuses code by creating new objects based on existing ones. A bird class inherits from animal (fly()), adding chirp().

Question 7

What is Polymorphism?

Answer 7

Objects of different classes respond differently to the same method. Animal class with subclasses dog (bark()) and cat (meow()), both having a makeSound() method.

Question 8

What are Classes and Objects in OOP?

Answer 8

A class is a blueprint that defines the properties and methods of similar objects. An object is an instance of a class, representing a specific entity with its own data and behavior.

Question 9

What are the benefits of OOP?

Answer 9

OOP promotes code reusability, maintainability, modularity, and data protection by organizing code into objects with well-defined functionalities.

Question 10

What is a Method in OOP?

Answer 10

A method is a function defined within a class that represents an action or behavior that the object can perform.

Question 11

What is a Property in OOP?

Answer 11

A property is a characteristic of an object that holds data and can be accessed or modified by methods.

Question 12

What are the different types of inheritance in OOP?

Answer 12

There are different types of inheritance like single inheritance (one subclass inherits from one superclass), multiple inheritance (subclass inherits from multiple superclasses), and hierarchical inheritance (forming a hierarchy of classes).

Question 13

What is the difference between public, private, and protected access modifiers in OOP?

Answer 13

Access modifiers control access to an object’s properties and methods. Public allows access from anywhere, private restricts access to the class, and protected allows access from within the class and subclasses.

Question 14

What is an Interface in OOP?

Answer 14

An interface defines a contract that specifies what methods a class must implement. It promotes loose coupling and enables polymorphism.

Question 15

What is the difference between a Class and an Instance in OOP?

Answer 15

A class is the blueprint, while an instance (object) is the specific realization of that blueprint with its own data.

Question 16

What is Abstraction in OOP achieved through?

Answer 16

Abstraction can be achieved through methods that hide internal implementation details and interfaces that define functionalities without specifying how they are implemented.

Question 17

What are the advantages of Encapsulation in OOP?

Answer 17

Encapsulation promotes data security by restricting direct access and improves code maintainability by keeping functionalities within a well-defined unit (object).

Question 18

What is Polymorphism beneficial for in OOP?

Answer 18

Polymorphism allows for flexible and dynamic behavior. You can write code that works with different objects without modifying it for each specific class.

Question 19

What are some challenges of using OOP?

Answer 19

OOP can introduce complexity if overused. Understanding relationships between objects and managing inheritance hierarchies can require careful planning.

Question 20

What is a constructor in OOP?

Answer 20

A constructor is a special method in a class that is called when an object is created. It’s used to initialize the object’s properties with starting values.

Question 21

What is the difference between static and non-static methods in OOP?

Answer 21

Non-static methods operate on data specific to an object instance. Static methods are associated with the class itself and can be accessed without creating an object.

Question 22

What is the role of getters and setters in OOP?

Answer 22

Getters and setters are methods used to control access to an object’s properties. Getters retrieve the property value, while setters modify it while potentially adding validation or security checks.