DEV Community: Akash

Abstraction in JAVA

Akash — Mon, 20 Jul 2026 08:45:27 +0000

Abstraction is the process of hiding internal implementation details and showing only essential Functionality.
Showing only necessary and hiding unwanted
If any single method in class is abstract then the whole class is known to be a abstract class
Object cannot be created in abstract class

=> Abstraction can be classified into two types

Abstract Class
Interface

1.Abstract Class

It cannot be instantiated
contains abstract methods
Abstract class is declared using the "abstract" keyword
Abstract class can contain both abstract and non-abstract methods 1.

public abstract class Netflix
{
public abstract void watchfifa();
public void dark(){
System.out.println("Crime Thriller-Dark");
}
public void peakyblinder()
{
System.out.println("Early 20's Gangster film ");
}
}

public class OTT extends Netflix
{
public static void main(String[]args)
{
OTT ott=new OTT();
ott.peakyblinder();
ott.dark();
ott.watchfifa();
}
public void watchfifa(){
System.out.println("Spain won world cup");
}
}

OUTPUT:

Encapsulation in JAVA

Akash — Fri, 17 Jul 2026 09:00:34 +0000

Binding Data(variable) and code together(Method)
It restrict direct Access to Data
Controls access through Getter and Setter methods

=> Why Encapsulation

Prevents data from unauthorised access
Ensures security
maintainability

=> Super class
public class Joyalukkas
{

private int price=1000;

public int getprice()
{
return this.price;
}


public void setprice(int price){
this.price=price;
}

}

=> Sub class
public class Buyer
{

public static void main (String[]args)
{

Joyalukkas joyalukkas=new Joyalukkas();
System.out.println(joyalukkas.getprice());
}
}

OUTPUT:

=> Getter Method

Getter method is a public method used to read the value of private variable from outside of the class

=> Setter Method

Setter method is a public method used to modify the value of private variable from outside of the class

Method Overriding in java

Akash — Thu, 16 Jul 2026 08:28:12 +0000

Method overriding is also called as Runtime Polymorphism
child class provides its own implementation of a method that already exists in the parent class. *

=> Parent Class
public class Parent
{

public static void main(String[]args)
{

Parent Parent=new Parent();
Parent.fixmar();

}

public void fixmar(){

System.out.println("We chose perfect partner for you  ");

}

}
=> Child Class
public class Child extends Parent
{

public static void main(String[] args)
{

Child Child=new Child();
Child.fixmar();
Parent Parent=new Parent();
Parent.fixmar();
}

public void fixmar()
{

System.out.println(" I have my opinion");
}
}

OUTPUT:

*=> Rules for Method Overriding
*

child class must inherit from the parent class using (extends)
Method name must be the same
Parameter must be the same
Return type must be the same
Access should not be Reduced
Method Overriding requires inheritance (extends)

Datatypes in java,Creating Class in Java

Akash — Thu, 02 Jul 2026 09:08:24 +0000

=> Datatypes in java

1. Primitive Datatype

Byte
Short
int
long
float
double
boolean

2. Non-Primitive Datatypes

String
Arrays
Classes
Interfaces

*=> There are several important rules in java for creating class
*

1.Keyword is Mandatory(class)
2.Class name should start with uppercase
3.Java is case-sensitive
4.Keywords must be lowercase
5.Leaving Spaces not allowed in class names

=> Declaring variable

int - Datatype
age - Variable name
= - Assignment operator
22 - Value

OUTPUT:

A variable declared inside the main() method is called a local variable.
Can be accessed using the class name
It can only be accessed inside main().

1.Game.name
2.Game.age
3.Game.qualification

Why JAVA over any other language ?

Akash — Fri, 26 Jun 2026 09:05:02 +0000

Java is object-oriented programming language used in backend development,used to build applications, especially backend systems, Android apps, enterprise software, and web applications.

=> why JAVA?

Large ecosystem
Strong OOPS
Mostly used in companies for backend
Platform independent
large-scale backend systems

=> Topics included in Java

OOPS
To write reusable, organized, real-world software.
Array & string
To store and manipulate multiple values and text.
Control Statement
To control program flow and create logic.
Packages
To organize large Java projects.
Exception handling
To handle runtime problems without crashing programs.
Collection Framework
Real applications store and manage large amounts of data.
Multi threading
To perform multiple tasks simultaneously.
Java Memory concept
To understand how Java manages memory.
Frameworks
Because companies always used pre written CODE for thier beneficial
instead of writing everytime .

=> Scope for JAVA in future

Many companies using java as backend for thier benefits,why because they have already written code instead of writing from scratch they use a thier existing code so they prefer java as thier backend language.
Java is Stable and reliable
Java is strong for performance

=> Technologies in java

Core java foundation
JBDC (Java Database Connectivity)
Spring Framework
Android Development
Microservices Technologies
Advanced Java Concepts

Justifying JAVA is OOPS

Akash — Thu, 25 Jun 2026 08:22:30 +0000

1.Java is a object oriented programming language(OOPS) why because it designed based on the concept classes and objects.

In java many programs created by defining a objects and classes.

          Class → Blueprint
          Object → Real thing created from the blueprint

=> Purpose of using OOPS

we can Write code once and use it many times by using inheritance.
We can protect Data by Hiding important data using encapsulation.
Divide a big program into smaller classes and objects.
Easy Maintenance
Better Security
Supports large Applications

=> justification of OOPS

Class
It is a blueprint or Template of Object
Object
It is a combination of States and Behaviour
Also it is a real or physical world entity

3.Inheritance

An object of one class acting as an object of another class

=> Paradigm in java

java supports paradigm also it supports multiple paradigm classifications of paradigm in java

Object-oriented paradigm -Built in around Classes and object
Procedural Paradigm-can use methods and functions
Functional programming paradigm -Uses expressions like (Lambda Expression,streams API

=> Pillars of OOPS

Encapsulation
Inheritance
Abstraction
Polymorphism

Java's Basic Architecture and confirming java is case sensitive language

Akash — Wed, 24 Jun 2026 08:57:41 +0000

JAVA
A code written by programmer in high level language and it converts into byte code with helps of JDK (Java Development Kit ) process known as compilation .
JRE (Java Runtime Environment) environment needed to run Java programs JVM (Java Virtual Machine) executes Java bytecode

 1.public class Game
{

public static Void main(String[] args)
{
    System.out.println("Hello world from java program");
}

}

 2. public class Game
{

public static void main(String[] args)
{
    System.out.println('Hello world from java program');
}

}

![ ](https://dev-to-uploads.s3.us-east-2.amazonaws.com/uploads/articles/emv1u4sqm0ejtz0s7n8t.png)

public class Print
{

public static void main(String[] args)
{
    System.out.println("Hello world from java program");
}

}

public class Game
{

public static void main(String[] args)
{
    System.out.println("Hello world from java program")
}

}

public class Game
{

public static void main(String[] args)
{
    System.out.println("Hello world from java program");
}

Python Exercises

Akash — Tue, 16 Jun 2026 08:41:44 +0000

=> Finding Power

To find the power of a number using a loop in Python, you multiply the number repeatedly.

def find_power(base,power):
   result=1
   while power>0:
      result=result*base
      power-=1
   return result
result=find_power(1,2) 
print(result)

OUTPUT:

=>Armstrong Number

An Armstrong number is a number where the sum of each digit raised to the power of the number of digits equals the original number.

def find_power(base, power):
    result = 1
    while power > 0:
        result = result * base
        power-=1

    return result
def count_of_digit(num):
    count = 0
    while num > 0:
        num = num // 10
        count+=1
    return count
num = 153
og_num=num
digits_count = count_of_digit(num)
armstrong = 0
while num > 0:
    rem = num % 10
    result = find_power(rem, digits_count)
    armstrong = armstrong + result
    num = num // 10

print(armstrong)

if og_num == armstrong: 
    print(" Armstrong Number")
else:
    print("Not Armstrong")

OUTPUT:

useReducer Hook

Akash — Tue, 09 Jun 2026 07:40:13 +0000

useReducer is a React Hook used to manage complex state logic.
Also it is used as alternative for useState,useReducer is used to make a cleaner and understandable code .

const [count, dispatch] = useReducer(reducer, initialState);

1.Count-current state
2.Dispatch-function

Creating Quiz Application

Akash — Wed, 03 Jun 2026 09:11:54 +0000

Create Components

App.jsx
Home.jsx
Question.jsx
Result.jsx

=> In App.jsx

Create a global variable for use variable in all other components
Also Create BrowserRouter for nagivate from on component to another Component
Import essentials components where it needed to implement program
also import Question .json file here i import in assests in src folder

=> Home.jsx

=> Question.jsx

=>Result.jsx

Python Looping Mathematics

Akash — Sat, 30 May 2026 05:29:40 +0000

=> Python Looping Mathematics Helping Factors
1.Prime Numbers

Prime number is a number greater number that has exactly two Factors (e.g) 1,2,5,7,

2.Factors

A number that divides another number without leaving a remainder. (e.g) 1,2,3,4,6,12

3.Least Common Multiple

Smallest common multilple of two numbers

(e.g) 4 and 6
4->4,8,,12,16,20
6->6,12,18,24
here least common multiple is 12.

OUTPUT:

4.Greatest Common Factor

A largest number that divides both numbers

(e.g) 12 and 18
12->1,2,3,4,6,12
18->1,2,3,6,9,18
here common factors are 1,2,3,6

5.Perfect Number
Perfect number is equals to sum its factors

(e.g) 6
1,2,3,6 are factors of 6
1+2+3=6
so,6 is a perfect number

OUTPUT:

useContext and useNavigate

Akash — Fri, 29 May 2026 06:00:59 +0000

=>USECONTEXT

It is a React Hook used to share data between components without passing props manually at every level.
Used to solve Props Drilling

=> USENAVIGATE

useNavigate is a React Router hook that lets you navigate between pages using JavaScript code.

1.Login Scenario

OUTPUT:

2.Logout Scenario

OUTPUT:

3.Namesharing Scenario

OUTPUT:

4.ButtonNavigation Scenario

OUTPUT:

5.Back Navigation Scenario

OUTPUT: