Features of OOP

Question 1

What is Abstraction

Answer 1

The process of simplifying a situation to only consider relevant details

Question 2

Benefits of Abstraction

Answer 2

helps create modular code by breaking down complex systems into smaller simpler units making the code more organized.
Additionally it also helps code comprehension as abstraction hides unneccessary information allowing developers to put their focus towards relevant information making it easier for them to understand

Question 3

What is Inheritance

Answer 3

is when a subclass inherits from the super class as it takes in all its properties and methods.

Question 4

Benefits of inheritance

Answer 4

Child classes inherit data and actions from the superclass, therefore, the child class can add new functionality or redefine the data and actions to better suit the sub class
Additionally, inheritance helps in maintanence as in the event that the super class has to be altered, the subclasses will not need to also be altered, saving time.

Question 5

What is polymorphism

Answer 5

when a method takes multiple forms

Question 6

What is overloading

Answer 6

overloading is when a method of the same name in the same class is used but has a different parameter.

Question 7

What is overriding

Answer 7

when the same method is used in different classes (parent and child) with different behaviours.

Question 8

When does one overload and when should someone override

Answer 8

one should over load if
When you want to create multiple methods with the same name but different parameters (different number or types).
when there are different inputs needed for similar behaviour
not suitable for customizing behaviour based on different method signatures in the same class

one should override if
When you want to change the behavior of a method in a subclass that is already defined in a parent class.

Question 9

explain the difference between overloading and overriding

Answer 9

overloading is when a method of the same name in the same class has different parameters
Overriding however is when the same method is used in different classes with different behaviours

Question 10

What does the keyword super mean

Answer 10

They keyword super calls the constructor of the super class and initiallizes the inherited fields

Question 11

what is encapsulation

Answer 11

encapsulation refers to the inclusion of both data and actions into one single component

Question 12

Benefits of encapsulation

Answer 12

Modularity as for a programmer they dont need to know how the class is storing its name field
the programmer of class Person can change the inner workings of the class provided the methods behave the same so that no external code should break as a result.

Question 13

What are access modifiers and what do each of them do

Answer 13

access modifiers are essential tools that define how the members of a class, and even the class itself can be accessed from other parts of our program.

these are

public, any class can access it
private, only the super class can access it
protected, only the superclass and its subclasses can access it

Question 14

what does the key word static mean

Answer 14

The static keyword is used for a constant variable or a method that is the same for every instance of a class.

Question 15

What is a static variable

Answer 15

A shared class-level data

Question 16

static method

Answer 16

invoked without an instance and cannot be overriden

Question 17

When do we use the term this?

Answer 17

to diffrentiate between the parameters and instane variables of a object

Question 18

what does The term final mean

Answer 18

Final is used to create a constant in Java
Constants are usually class variables instead of instance variables but in some cases they are instance variables

Question 19

what is a final variable

Answer 19

is immutable once it is assigned

Question 20

what is a final method

Answer 20

A final method cannot be overridden by subclasses

Question 21

Primitive data types

Answer 21

a predefined identifier provided by the programming language as a basic building block

Question 22

what is String class

Answer 22

string class is an object in java, its part of the java language and has methods to help manipulate the data

Question 23

What is ASCII?

Answer 23

It is a character encoding scheme widely used in computers and communication systems. Uses 7 bits to represent characters, allowing for 128 unique characters.

Question 24

Disadvantages of ASCII

Answer 24

the disadvantage of ASCII is that many languages contain many more characters, its bit range is very small allowing for only 128 unique characters which means languages with more characters are limited when using ASCII and its mainly useful only to the english language

Question 25

the solution of ASCII

Answer 25

Unicode expands upon the limitations of ASCII by using a larger bit range, allowing it to represent a vast number of characters (over 1 million) from various languages and scripts.

Question 26

pass by value

Answer 26

Pass by value is a method of passing arguments to functions where a copy of the actual value is made and passed to the function. This means that any changes made to the parameter inside the function do not affect the original variable outside the function.

Question 27

What are libraries of objects?

Answer 27

They are collections of classes that have already been written in code and can be used by a programmer while developing a program.

Question 28

Advantages of libraries of objects

Answer 28

Reusable classes and methods eliminate the need to write code from scratch Ensures reliability; Libraries contain tested and proven code, reducing bugs

Question 29

Disadvantages of OOP

Answer 29

For small projects, with few developers and modules OOP may increase complexity, development time and maintenance costs. Programming in OOP requires care in order not to make projects too abstract which lead to unnecessarily large and complex programs

Question 30

use of individual programmer (Positive and negative)

Answer 30

Positive Have an overall view of the whole project and able to make changes quickly| Does not need to develop a common language with his/her peers, since there is no collaboration and coordination needed Negative Not suitable for bigger projects as developer would need much more time than available to complete the project on time.

Question 31

use of groups of programmers

Answer 31

Positives Larger projects can be taken, since more developers can work on them Compared to solo developers member of a team may bring various ideas to the table that would not have come about without member collaboration Negatives The weaknesses of some team members may end up undermining the group Decisions and planning takes longer

Question 32

Advantages of modularity in program development

Answer 32

A sub-program developed for one application may be used in other (log in, user profile, google functions) applications that need to have the same functionality Less new code need to be written for a program

Question 33

Moral and ethical obligations of programmers

Answer 33

Thoroughly test their products before providing them to the public. This ensures they operate as expected and any possibility of commercial or other damage has been minimized. Obliged to give credit to the intellectual property of others when they include such work in their projects.