Object Oriented Programming (OOP)

Question 1

Define object.

Answer 1

An object is an instance of a class.

Question 2

What is the need for self in classes?

Answer 2

self is used to reference the current instance of a class. It is used to access the attributes and methods of the class within its own definition.

Question 3

Define attribute.

Answer 3

An attribute is a characteristic of an entity or object.

Question 4

What is inheritance?

Answer 4

Inheritance is the retrieval of all the methods and attributes from a super class, so they can be used within a sub-class.

Question 5

What is encapsulation?

Answer 5

Encapsulation is the bundling of attributes and methods together within a class. The attributes should only be accessed and modified by the classs own methods.

Question 6

What is OOP?

Answer 6

OOP stands for Object-Oriented Programming. It is a way of coding that involves classes, objects, and methods.

Question 7

Define method.

Answer 7

A method is an implementation of behavior inside a class.

Question 8

What are static methods?

Answer 8

Static methods are methods that dont require instantiation or self. They can be relevant to the class, but may not require any of the attributes in the constructor method.

Question 9

What is instantiation?

Answer 9

Instantiation is the process of creating a new instance of a class or an object.

Question 10

What is an access modifier?

Answer 10

An access modifier is used in object-oriented programming to control the visibility of class attributes and methods. There are three types: public, protected, and private.

Question 11

What is encapsulation?

Answer 11

Encapsulation is the bundling of attributes and methods together within a class, where a classs attributes should only be accessed and modified by its own methods (getters and setters). It ensures code security and efficiency.

Question 12

What is the mantra of object-oriented programming?

Answer 12

The mantra of object-oriented programming is to favor composition over inheritance, program to interfaces rather than implementations, and ensure code security and usability for users.

Question 13

What are getters and setters?

Answer 13

Getters are simple return statements used to retrieve attributes. Setters usually take in parameters and are used to modify attributes. They can also include validation.

Question 14

Why should you encapsulate what varies?

Answer 14

Encapsulating what varies ensures that the code is accurate and representative of the desired blueprint. It also improves code security and efficiency. If something can change in any circumstance, it needs to be encapsulated to prevent potential issues.

Question 15

What is overriding?

Answer 15

Overriding is where you have a method in the superclass and want it to behave differently in the subclass. It is a form of polymorphism.

Question 16

Define class.

Answer 16

A class is a custom data type that acts as a blueprint for creating objects, attributes, and methods.

Question 17

What is aggregation?

Answer 17

Aggregation is passing in a whole object outside of a class. Uses-a relationship, where objects can exist separately.

Question 18

What is composition?

Answer 18

Composition is creating an instance of the main class within the other class, and assigning it to an object. It represents an intrinsic link or has-a relationship. Objects cannot exist separately

Question 19

What is polymorphism?

Answer 19

Polymorphism is the ability of a method to exhibit different behavior depending on the object on which the method is invoked.

Question 20

Why is composition favored over inheritance?

Answer 20

Composition is favored over inheritance because inheritance can lead to redundancy and poor memory usage. Inheritance inherits all the data even if its not needed, while composition allows for more efficient and secure code. Additionally, composition does not break encapsulation.