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IRC – My Understanding V2.0

What is plaintext in my point of view:
Its simply text without any makeup or add-on, it is just an organic content. For example,

  • A handwritten grocery list what our mother used to give to our father
  • A To-Do List
  • An essay/composition writing in our school days

Why plaintext is important?
– The quality of the content only going to get score here: there is no marketing by giving some beautification or formats.
– Less storage
– Ideal for long term data storage because Cross-Platform Compatibility
– Universal Accessibility. Many s/w using plain text for configuration files (.ini, .conf, .json)
– Data interchange (.csv – interchange data into databases or spreadsheet application)
– Command line environments, even in cryptography.
– Batch Processing: Many batch processes use plain text files to define lists of actions or tasks that need to be executed in a batch mode, such as renaming files, converting data formats, or running programs.

So plain text is simple, powerful and something special we have no doubt about it.

What is IRC?
IRC – Internet Relay Chat is a plain text based real time communication System over the internet for one-on-one chat, group chat, online community – making it ideal for discussion.

It’s a popular network for free and open-source software (FOSS) projects and developers in olden days. Ex. many large projects (like Debian, Arch Linux, GNOME, and Python) discussion used. Nowadays also IRC is using by many communities.

Usage :
Mainly a discussion chat forum for open-source software developers, technology, and hobbyist communities.

Why IRC?
Already we have so many chat platforms which are very advanced and I could use multimedia also there. So this is very basic, right?

Yes it is very basic, but the infrastructure of this IRC is not like other chat platforms. In my point of view the important differences are privacy and decentralized.

Advantages over other Chat Platforms:

  • No Ads Or Popups: We are not distracted from other ads or popups because my information are not passed to any company to track my needs and give marketing.
  • Privacy: Many IRC networks does not need your email or mobile number or even registration. Simply you can type your name or nick name, select your server and start chat instantly. Chat Logs also getting stored if required.
  • Open Source and Free: Server, Client – the entire networking model is free and open source. Anybody can install the IRC servers/clients and connect with the network.
  • Decentralized : As servers are decentralized, it could able to work even one server has some issues and it is down. Users can connect to different servers within the same network which is improving reliability and performance.
  • Low Latency: Its a free real time communication system with low latency which is very important for technical communities and time sensitive conversations.
  • Customization and Extensibility: Custom scripts can be written to enhance functionality and IRC supports automation through bots which can record chats, sending notification or moderating channels, etc.
  • Channel Control: Channel Operators (Group Admin) have fine control over the users like who can join, who can be kicked off.
  • Light Weight Tool: As its light weight no high end hardware required. IRC can be accessed from even older computers or even low powered devices like Rasberry Pi.
  • History and Logging: Some IRC Servers allow logging of chats through bots or in local storage.

Inventor
IRC is developed by Jarkko Oikarinen (Finland) in 1988.

Some IRC networks/Servers:
Libera.Chat(#ubuntu, #debian, #python, #opensource)
EFNet-Eris Free Network (#linux, #python, #hackers)
IRCnet(#linux, #chat, #help)
Undernet(#help, #anime, #music)
QuakeNet (#quake, #gamers, #techsupport)
DALnet- for both casual users and larger communities (#tech, #gaming, #music)

Some Clients-GUI
HexChat (Linux, macOS, Windows)
Pidgin (Linux, Windows)
KVIrc (Linux, Windows, macOS)

Some IRC Clients for CLI (Command Line Interface) :
WeeChat
Irssi

IRC Clients for Mobile :
Goguma
Colloquy (iOS)
LimeChat (iOS)
Quassel IRC (via Quassel Core) (Android)
AndroIRC (Android)

Directly on the Website – Libera WebClient – https://web.libera.chat/gamja/You can click Join, then type the channel name (Group) (Ex. #kaniyam)

How to get Connected with IRC:
After installed the IRC client, open.
Add a new network (e.g., β€œLibera.Chat”).
Set the server to irc.libera.chat (or any of the alternate servers above).
Optionally, you can specify a port (default is 6667 for non-SSL, 6697 for SSL).
Join a channel like #ubuntu, #python, or #freenode-migrants once you’re connected.

Popular channels to join on libera chat:
#ubuntu, #debian, #python, #opensource, #kaniyam

Local Logs:
Logs are typically saved in plain text and can be stored locally, allowing you to review past conversations.
How to get local logs from our System (IRC libera.chat Server)
folders – /home//.local/share/weechat/logs/ From Web-IRCBot History:
https://ircbot.comm-central.org:8080/

References:
https://kaniyam.com/what-is-irc-an-introduction/
https://www.youtube.com/watch?v=CGurYNb0BM8

Our daily meetings :
You can install IRC client, with the above link help, can join.
Timings : IST 8pm-9pm
Server : libera.chat
Channel : #kaniyam

ALL ARE WELCOME TO JOIN, DISCUSS and GROW

Collections Tasks

TASKS:

  • // 1. Reverse an ArrayList without using inbuilt method
  • // 2. Find Duplicate Elements in a List
  • // 3. Alphabetical Order and Ascending Order (Done in ArrayList)
  • // 4. Merge Two Lists and Remove Duplicates
  • // 5. Removing Even Nos from the List
  • // 6. Array to List, List to Array
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;


public class CollectionsInJava {
	public static void main(String[] args) {
		// 1. Reverse an ArrayList without using inbuilt method
		// 2. Find Duplicate Elements in a List 
		// 3. Alphabetical Order and Ascending Order (Done in ArrayList)
		// 4. Merge Two Lists and Remove Duplicates
		// 5. Removing Even Nos from the List
		// 6. Array to List, List to Array
		ArrayList<String> names = new ArrayList<>(Arrays.asList("Abinaya", "Ramya", "Gowri", "Swetha",  "Sugi", "Anusuya", "Moogambigai","Jasima","Aysha"));
		ArrayList<Integer> al2 = new ArrayList<>(Arrays.asList(100,90,30,20,60,40));
		
		ArrayList<Integer> al =  insertValuesIntoAL();
		System.out.println("Before Reversing ArrayList="+ al);
		System.out.println("Reversed ArrayList="+ reverseArrayList(al));
		
		System.out.println("Duplicates in ArrayList="+findDuplicates(al));
		
		System.out.println("Before Order = "+names);
		Collections.sort(names);
		System.out.println("After Alphabetical Order = " + names);
		Collections.sort(al);
		System.out.println("Ascending Order = "+ al);
		
		System.out.println("List -1 = "+al);
		System.out.println("List -2 = "+al2);
		System.out.println("After Merging and Removing Duplicates="+mergeTwoLists(al,al2));
		System.out.println("After Removing Even Nos fromt the List-1 = "+removeEvenNos(al));
		
		arrayToListViceVersa(al,new int[] {11,12,13,14,15}); //Sending ArrayList and anonymous array
	}
	
	// 1. Reverse an ArrayList without using inbuilt method
	private static ArrayList<Integer> reverseArrayList(ArrayList<Integer> al) {
		int n=al.size();
		int j=n-1, mid=n/2;
		for (int i=0; i<mid; i++) {
			int temp = al.get(i);
			al.set(i, al.get(j));
			al.set(j--, temp);
		}
		return al;
	}
	
	// 2. Find Duplicate Elements in a List 
	private static ArrayList<Integer> findDuplicates(ArrayList<Integer> al) {
		HashSet<Integer> hs = new HashSet<>();
		ArrayList<Integer> arl = new ArrayList<>();
		for (int ele:al) {
			if (!hs.add(ele)) arl.add(ele);
		}
		return arl;
	}
	
	//4. Merge Two Lists into one and Remove Duplicates
	private static HashSet<Integer> mergeTwoLists(ArrayList<Integer> arl1,ArrayList<Integer> arl2) {
		ArrayList<Integer> resAl = new ArrayList<>();
		HashSet<Integer> hs = new HashSet<>();
		hs.addAll(arl1);
		hs.addAll(arl2);
		return hs;
	}
	
	// 5. Removing Even Nos from the List
	private static ArrayList<Integer> removeEvenNos(ArrayList<Integer> al) {
		ArrayList<Integer> res = new ArrayList<>();
		Iterator itr = al.iterator();
		while (itr.hasNext()) {
			int ele = (int)itr.next();
			if (ele%2==1) res.add(ele);
		}
		return res;
	}
	
	// 6. Array to List, List to Array
	private static void arrayToListViceVersa(ArrayList<Integer> arl, int[] ar) {
		Integer arr[] = arl.toArray(new Integer[0]);
		System.out.println("Convert List to Array = " + Arrays.toString(arr));
		List<Integer> lst = Arrays.asList(arr);
		System.out.println("Convert Array to List = " +  lst);
	}
	
	private static ArrayList<Integer> insertValuesIntoAL() {
		Integer[] ar = {30,40,60,10,94,23,05,46, 40, 94};
		ArrayList<Integer> arl = new ArrayList<>();
		Collections.addAll(arl, ar);
		//Collections.reverse(al);   //IN BUILT METHOD
		return arl;
			//Arrays.sort(ar);  
		//List lst = Arrays.asList(ar);    //TBD
		//return new ArrayList<Integer>(lst);
		
	}

}

OUTPUT:

Exception Handling

What is Exception?

An Exception is an unexpected or unwanted event which occurs during the execution of a program that typically disrupts the normal flow of execution.

This is definition OK but what I understand : The program’s execution is getting stopped abnormally when it reaches some point which have some mistake/error – it may be small or big, compilation or runtime or logical mistake. And its not proceeding with further statements. Handling this situation is called exception handling. Cool. Isn’t it?

Why Exception Handling?

If we do not handle the exception program execution will stop. To make the program run smoothly and avoid stopping due to minor issues/exceptions, we should handle it.

So, how it is represented, In Java everything is class, right? The derived classes of java.lang.Throwable are Error and Exception. For better understanding lets have a look at the hierarchical structure.

Here I could see Exception and Error – when we hear these words looks similar right. So What could be the difference?

Errors are some serious issues which is beyond our control like System oriented errors. Ex. StackOverFlowError, OutOfMemoryError (Lets discuss this later).

Exception is a situation which we can handle,

  1. through try-catch-(finally) block of code
  2. Throws keyword in method signature.

try-catch-Finally :

What is the meaning? As we are the owner of our code, we do have some idea about the possible problems or exceptions which we can solve or handle through this try-catch block of code.

For Ex. Task : Make a Tasty Dish.

What could be the exceptions?

  1. Some spice added in lower quantity.
  2. Chosen vessel may be smaller in size
  3. some additional stuff may not be available

To overcome these exception we can use try-catch block.

try {
  Cooking_Process();
}
catch(VesselException chosenLittle) {
   Replace_with_Bigger_One();
}
catch(QtyException_Spice spiceLow) {
   add_Little_More_Spice();
}
catch(AddOnsException e) {
  ignore_Additional_Flavors_If_Not_Available();
}
catch(Exception e) {
  notListedIssue();
}
Finally {
  cleanUp_Kitchen();
}

Here there could be more catches for one try as one task may encounter many different issues. If it is solvable its called exception and we try to catch in catch blocks. The JVM process our code (cookingProcess) and if it encounter one problem like QtyException_Spice, it will throw the appropriate object. Then it will be caught by the corresponding catch, which will execute add_Little_More_Spice() and prevent the code from failing.

Here we see one more word, Exception, which is the parent class of all exceptions. Sometimes we may encounter the issue that is not listed (perhaps forgotten) but its solvable. In such cases, we can use the parent class object (since a parent class object can act as a child object) to catch any exception that is not listed.

Fine, all good. But what is the purpose of Finally here? Finally is the block of code that will always be executed, no matter if exception occurs or not. It doesn’t matter if you made a good dish or a bad one, but the kitchen must be cleaned. The same applies here: the finally block is used for releasing system resources that were mainly used (Ex. File). However, we can also write our own code in the finally block based on the specific requirements.

We have a situation where you have one cylinder to cook, and it gets emptied during cooking, so we cannot proceed. This will fail our process TastyDish, this situation cannot be handled immediately. This is called Error. Now lets recall the definition β€œErrors are serious issues that are beyond our control like a system crash or resource limitations.” Now we could understand, right?

Ex. OutOfMemoryError – when we load too much data, JVM runs out of memory. StackOverFlowError – when an infinite loop or recursion without base condition will make the stack overflow.

Lets revisit exceptions – they can be classified into two categories:

  • Checked Exception
  • UnChecked Exception.

What is Checked Exceptions?

Checked Exception is the exception which occurs at compile time. It will not allow you to run the code if you are not handling through try-catch or declares throws method.

Lets get into deeper for the clear understanding, the compiler predicts/doubts the part of our code which may throw the exceptions/mistakes which lead to stopping the execution. So that it will not allow you to run, it is forcing you to catch the exception through the above one of mechanisms.

If it is not clear, let us take an example, in the above code we have VesselException and QtyException_Spice . You are at your initial stage of cooking under the supervision of your parent. So we are ordered/ instructed to keep the big vessel and the spices nearby in case you may need it when the problem arise. If you are not keeping it nearby parent is not allowing you to start cooking (initial time ). Parent is compiler here.

throws:

So Expected exception by the compiler is called Checked Exception, and the compiler force us to handle. One solution we know try-catch-finally, what is that through declaration in the method? The exception in which method can be expected, that method should use the keyword β€œthrows <ExceptionClassName-1>” that is, it specifies this method may lead to the exceptions from the list of classes specified after throws keyword. After throws can be one class or more than one. whoever using this method with this declaration in method signature will aware of that and may handle it.

The good example for this is, IOException (parent) – FileNotFoundException (child). If you are trying to open a file, read it, the possible exceptions are: File Path Incorrect, File doesn’t exist, File Permission, Network issues etc. For Ex.

public static void main(String[] args) {
        try {
            // Calling the method that may throw a FileNotFoundException
            readFile("nonexistentfile.txt");
        } catch (FileNotFoundException e) {
            // Handle exception here
            System.out.println("File not found! Please check the file path.");
            e.printStackTrace();
        }
    }   

 // Method that throws FileNotFoundException
    public static void readFile(String fileName) throws FileNotFoundException {
        File file = new File(fileName);
        Scanner scanner = new Scanner(file);  // This line may throw FileNotFoundException
        while (scanner.hasNextLine()) {
            System.out.println(scanner.nextLine());
        }
        scanner.close();
    }

What is Unchecked Exception?

The compiler will not alert you about this exception, instead you will experience at runtime only. This not required to be declared or caught, but handling is advisable. These are all subclasses of RunTimeException (Error also will throw runtime exception only). It could be thrown when runtime issues, illegal arguments, or programming issues.

Ex.Invalid index in an array, or trying to take value from a null object, or dividing by zero.

Ex. NullPointerException

String str = null; System.out.println(str.length()); /* Throws NullPointerException */

ArrayIndexOutOfBoundsException

int[] arr = new int[3]; System.out.println(arr[5]); /* Throws ArrayIndexOutOfBoundsException */

What is throw?

Instead JRE throws error, the developer can throw the exception object (Predefined or UserDefined) to signal some erroneous situation and wants to stop the execution. For ex, you have the idea of wrong input and wants to give your own error message.

public class SampleOfThrow {
    public static void main(String[] args) {
        // a/b --> b should not be 0
        Scanner scn = new Scanner(System.in);
        int a = scn.nextInt();
        int b = scn.nextInt();
        if (b==0) throw new ArithmeticException("b value could not be zero");
        System.out.print(a/b);
    }
}

Hey, wait, I read the word, User Defined Exception above. which means the developer (we) also can create our own exception and can throw it. Yes, absolutely. How? In Java everything is class, right? So through class only, but on one condition it should extend the parent Exception class in order to specify it is an exception.

//User Defined Exception
class UsDef extends Exception {
    public UsDef(String message) {
        super(message); //will call Exception class // and send the own error message
    }
}

public class MainClass {
    public static void main(String[] args) {
        try {
            Scanner scn = new Scanner(System.in);
            boolean moreSalt = scn.nextBoolean(); 
            validateFood(moreSalt);
 // This method will throw an TooMuchSaltException
        } catch (TooMuchSaltException e) {
            System.out.println(e.getMessage());  // Catching and handling the custom exception
        }
    }

    // Method that throws TooMuchSaltException if food contains too much salt and can't eat
    public static void validateFood(boolean moreSalt) throws TooMuchSaltException {
        if (moreSalt) {
            throw new TooMuchSaltException("Food is too salty.");
        }
        System.out.println("Salt is in correct quantity");
    }
}

Now Lets have a look at some important Exception Handling points in java of view. (The following are taken from chatGPT)

Error Vs. Exception

AspectErrorException
DefinitionAn Error represents a serious problem that a Java application cannot reasonably recover from. These are usually related to the Java runtime environment or the system.An Exception represents conditions that can be handled or recovered from during the application’s execution, usually due to issues in the program’s logic or input.
Superclassjava.lang.Errorjava.lang.Exception
RecoveryErrors usually cannot be recovered from, and it is generally not advisable to catch them.Exceptions can typically be caught and handled by the program to allow for recovery or graceful failure.
Common TypesOutOfMemoryError, StackOverflowError, VirtualMachineError, InternalErrorIOException, SQLException, NullPointerException, IllegalArgumentException, FileNotFoundException
Occurs Due ToTypically caused by severe issues like running out of memory, system failures, or hardware errors.Typically caused by program bugs or invalid operations, such as accessing null objects, dividing by zero, or invalid user input.
Checked or UncheckedAlways unchecked (extends Throwable but not Exception).Checked exceptions extend Exception or unchecked exceptions extend RuntimeException.
Examples– OutOfMemoryError
– StackOverflowError
– VirtualMachineError
– IOException
– SQLException
– NullPointerException
– ArithmeticException
HandlingErrors are usually not handled explicitly by the program. They indicate fatal problems.Exceptions can and should be handled, either by the program or by throwing them to the calling method.
PurposeErrors are used to indicate severe problems that are typically out of the program’s control.Exceptions are used to handle exceptional conditions that can be anticipated and managed in the program.
Examples of Causes– System crash
– Exhaustion of JVM resources (e.g., memory)
– Hardware failure
– File not found
– Invalid input
– Network issues
ThrowingYou generally should not throw Error explicitly. These are thrown by the JVM when something critical happens.You can explicitly throw exceptions using the throw keyword, especially for custom exceptions.

Checked vs. Unchecked Exception:

AspectChecked ExceptionUnchecked Exception
DefinitionExceptions that are explicitly checked by the compiler at compile time.Exceptions that are not checked by the compiler, and are typically runtime exceptions.
SuperclassSubclasses of Exception but not RuntimeException.Subclasses of RuntimeException.
Handling RequirementMust be caught or declared in the method signature using throws.No explicit handling required; they can be left uncaught.
ExamplesIOException, SQLException, ClassNotFoundException.NullPointerException, ArrayIndexOutOfBoundsException, ArithmeticException.
Common UsageTypically used for exceptional conditions that a program might want to recover from.Used for programming errors or unforeseen runtime issues.
Checked atCompile-time.Runtime (execution time).
Effect on CodeForces the developer to handle the exception (either with a try-catch or throws).No such requirement; can be ignored without compiler errors.
Examples of CausesMissing file, network failure, database errors.Null pointer dereference, dividing by zero, illegal array index access.
When to UseWhen recovery from the exception is possible or expected.When the error typically indicates a bug or programming mistake that cannot be recovered from.

throw vs. throws:

Aspectthrowthrows
DefinitionUsed to explicitly throw an exception from a method or block of code.Used in a method signature to declare that a method can throw one or more exceptions.
UsageUsed with an actual exception object to initiate the throwing of an exception.Used in the method header to inform the compiler and the caller that the method might throw specific exceptions.
Keyword TypeStatement (flow control keyword).Modifier (appears in the method declaration).
Examplethrow new IOException("File not found");public void readFile() throws IOException { ... }
LocationCan be used anywhere inside the method or block to throw an exception.Appears only in the method signature, usually right after the method name.
ControlImmediately transfers control to the nearest catch block or exits the program if uncaught.Allows a method to propagate the exception up the call stack to the caller, who must handle it.
Checked vs UncheckedCan throw both checked and unchecked exceptions.Typically used for checked exceptions (like IOException, SQLException) but can also be used for unchecked exceptions.
Example ScenarioYou encounter an error condition, and you want to throw an exception.You are writing a method that may encounter an error (like file I/O) and want to pass the responsibility for handling the exception to the caller.

References : 1. https://www.geeksforgeeks.org/exceptions-in-java/

My First Public Speaking

Public Speaking – It’s just two words, but it makes many people feel frightened. Even I did. I felt embarrassed to stand in front of my schoolmates/colleagues.

Usually, I am present in college during working days, but if it’s seminar days, you can’t find me – I will be absent. But whatever you try to avoid in life, one day you’ll face it, right? That was what happened in my interview. Fear! Fear!!

But how could we compare an interview with public speaking? Why not? If the interview panel has multiple people, and they ask you questions you may or may not know the answers – but at least in public speaking, you will speak about what you know.

I still have that fear. So, I decided not to run away but FACE THE ISSUE. A few good people supported me in overcoming this situation. First, my professor Muthu Sir, who advised me to join open-source communities, specifically ILUGC and KanchiILUGC. He said, β€œJust join, they will take care of you if you follow them.” I joined, and under Mr. Shrini’s guidance, I started doing simple projects. In between, he asked me to give a presentation at an ILUGC meet.

I said OK immediately (I already wanted to overcome my fear). I felt I accepted in a rush, and suddenly had mixed feelings like run away πŸ™‚ But he was so fast – I received an email to give my name, and the formalities proceeded. The real race started in my heart.

My inner thoughts: β€œWhat, Sugi? What are you going to do? The subject is fine, but can you speak in front of people?”

I said to myself, It’s OK, whatever, I have to do. Then, Muthu Sir, Ms.Jothy, friends, classmates, my family and all others encouraged me.

I still remember what Muthu Sir said: β€œWhat’s the worst that can happen? One, you can do well. If so, you’ll feel good and confident. Two, you may not do well, but that will push you to do better next time. Both outcomes will yield good and positive results, so just go for it.”

Then I practiced alone and felt OK. I had some paper notes in my hand, but when the laptop screen turned on, my heart rate went up, and my hands started shaking. When people asked me to start, I said, β€œI am Sugirtha,” and then forgot everything.

Thank God I at least remembered my name! Fine, let’s see the paper – What is this? I couldn’t read it, nothing was going inside my brain. It felt like Latin, which I don’t understand. I threw the paper aside, started recollecting, and said, β€œHTML stands for HyperText Markup Language.” Inside, I thought, Oh my God, this is not my first line to say, I thought I would start differently. For about 5 to 10 minutes, I fumbled with the points but didn’t deliver them as I expected. But when I started working on the code, I felt OK, as I got immersed in it.

Finally, it was over. There was still some tension, and after some time, I thought, I don’t know if my presentation was good or not, but at least I finished it. Then, after a while, I thought, Oh God, you did it, Sugi! Finally, you did something.

Now, I wonder if I get another chance, could I do it again? Back then, I somehow managed, but now… the fear returns. But this not the same as before which I feel I can overcome easily. So to overcome this I have to do more and more. I don’t want to prove anything to anyone, but I just want to prove something to myself. For my own satisfaction, I want to do more. I feel I will do better.

If I can, why can’t you?

Address Book v2.0 as on 08Nov2024 – (DEVELOPMENT IN PROGRESS)

Project Title : Address Book

S/w Used : HTML, CSS, JavaScript with LocalStorage for storing data (little Bootstrap)

Framework Used : Text Editor

Description : A small addressbook which is having name, email, contact no, and city which is having CRUD operations.

Till Today :

  • From v1.0, design changed completely.
  • Code done for Adding new Contact with modal window.
  • And whenever new entry added that will get displayed in the table dynamically with del and edit buttons.
  • Delete button action also done.
  • Alignment I could not able to do well, so took chatGPT help.

To Do:

  • Edit action and Search are pending.
  • Add New screen is not getting closed after adding – has to be rectified.
  • Design should get changed in AddNew screen
  • Table – Headings font size should get changed. (As used bootstrap table class – th is not getting changed through css – have to research in it.
  • Some Code duplication is there, have to be optimized like keep in one function (inside validationPassed & addNewContact).

Technical WorkFlow:

function validationPassed : This function checks all the fields are not empty.

function getAddrBook : This function returns an Array which extracts the existing contacts from localStorage, if available, and parse it. Otherwise an empty array will be returned.

function addNewContact : If validationPassed, then new contact entry is created from 4 fields (Name, Email, ContactNo and City), together will form an object and pushed into addrBook array (got through getAddrBook) and will get saved into localStorage. showBook() function is getting called immediately to show the added contact.

function showBook() : This is actually a table where rows(contacts) with delete and edit buttons are getting added dynamically and will be shown.

function deleteCont(idx) : As the name suggests it will take the index of the array as input and delete the contact when the delete button pressed.

Output till now :

This image has an empty alt attribute; its file name is image-5.png

AddNew Screen:

gitlab : https://gitlab.com/Sugirtha/Kaniyam.git

Finding SubArray

package taskPkg;

import java.util.Scanner;

public class SubArray {

	public static void main(String[] args) {
		// FINDING SUBARRAY AND ITS POSITION
		System.out.println("Enter a sentence to search in.");
		Scanner scn = new Scanner(System.in);
		String sentn = scn.nextLine();
		System.out.println("Enter a word to be searched.");
		String word = scn.next();
		scn.close();
		char[] sentence = sentn.toCharArray();
		char[] key = word.toCharArray();
		int n = sentence.length, m = key.length;
		int i = 0, j = 0, st = 0; // i- maintain index in the sentence, j-maintain index in key
		boolean match = false;
		while (i < n && j < m) {// 
			//System.out.println("i=" + i + "     sentence[i]=" + sentence[i] + "    j=" + j + "   key[j]=" + key[j]);
			if (sentence[i] == key[j]) { //if it matches incrementing both pos
				i++;
				j++;
				if (j == m) { //if the key reaches end, made the match and exit
					match = true;
					break;
				}
			} 
			else {    // if no match move on to the next letter, but key should start from 0
				j = 0;
				i=st+1;
				st = i;  // this is to save the starting of the subarray
			}
		}
		if (match)
			System.out.println("SubArray is found at " + st);
		else
			System.out.println("SubArray is not found");
	}
}

OUTPUT:

2D Matrix Addition, Multiplication, Largest in EachRow, Is Descending Order

package taskPkg;

public class MatrixCalc {
	public static void main(String[] args) {
		// 1. MATRIX ADDITION ( A + B )
		// 2. MATRIX MULTIPLICATION ( C*D ) IF C is nxk AND D IS kxm RESULTANT MUST BE
		// nxm
		int[][] A = { { 4, 2, 5 }, { 6, 3, 4 }, { 8, 1, 2 } };
		int[][] B = { { 5, 1, 3 }, { 2, 3, 2 }, { 1, 6, 4 } };
		int[][] C = { { 4, 2 }, { 2, 1 }, { 5, 3 } };
		int[][] D = { { 1, 2, 3 }, { 3, 2, 5 } };
		int[] desc = { 9, 5, 2, 1 };
		int[][] M = new int[C.length][D[0].length];

		MatrixCalc matOp = new MatrixCalc();
		matOp.add(A, B);
		System.out.println("-------------------------");
		matOp.multiply(C, D, M);
		System.out.println("-------------------------");
		matOp.LargestInEachRow(M);
		System.out.println("-------------------------");
		matOp.isDescendingOrder(desc);
	}

	private void add(int[][] A, int[][] B) {
		int r = A.length, c = A[0].length;
		int[][] S = new int[r][c];
		for (int i = 0; i < r; i++) {
			for (int j = 0; j < c; j++) {
				S[i][j] = A[i][j] + B[i][j];
			}
		}
		print2Darray(A, "A");
		print2Darray(B, "B");
		System.out.println("SUM : S = A+B");
		print2Darray(S, "S");
		System.out.println();
	}

	private void multiply(int[][] C, int[][] D, int[][] M) {
		int n = C.length, q = D.length, m = D[0].length;
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < m; j++) {
				for (int k = 0; k < q; k++) {
					M[i][j] += C[i][k] * D[k][j];
				}
			}
		}
		print2Darray(C, "C");
		print2Darray(D, "D");
		System.out.println("MULTIPLY : M = CxD");
		print2Darray(M, "M");
	}

	private void LargestInEachRow(int[][] M) {
		int L[] = new int[M.length];
		System.out.println("LARGEST IN EACH ROW OF : M ");
		System.out.print("[");
		for (int i = 0; i < M.length; i++) {
			L[i] = M[i][0];
			for (int j = 0; j < M[0].length; j++) {
				L[i] = L[i] < M[i][j] ? M[i][j] : L[i];
			}
			System.out.print(" " + L[i] + " ");
		}
		System.out.println("]");
	}

	private void isDescendingOrder(int[] des) {
		boolean desc = true;
		System.out.print("Array des [");
		for (int i = 0; i < des.length; i++) {
			System.out.print(" " + des[i] + " ");
			if (i > 0 && desc && des[i - 1] < des[i])
				desc = false;
		}
		System.out.println("]");
		if (desc)
			System.out.println("Given Array des is In Descending Order");
		else
			System.out.println("Given Array des is NOT In Descending Order");
	}

	private void print2Darray(int[][] ar, String arName) {
		System.out.print("Array " + arName + " : ");
		for (int i = 0; i < ar.length; i++) {
			if (i > 0)
				System.out.print("          ");
			System.out.print("[");
			for (int j = 0; j < ar[0].length; j++) {
				System.out.print(" " + ar[i][j] + " ");
			}
			System.out.println("]");
		}
		System.out.println();
	}

}

OUTPUT:

Simple Student Mark List


import java.util.Scanner;

public class Array2DstudentsMarks {
	Scanner scn = new Scanner(System.in);
	String stud[];
	int[][] marks;
	int[] tot, highestScorer;
	int subj, totHighStud;
	public static void main(String[] args) {
		// STUDENTS MARKS WITH TOTAL - 2D ARRAY
		Array2DstudentsMarks twoDArray =  new Array2DstudentsMarks();
		twoDArray.studentMarksTotal();
		twoDArray.dispMarkAndTotal();
	}

	private void studentMarksTotal() {
		System.out.println("Enter no. of Students");
		int n = scn.nextInt();
		System.out.println("Enter no. of Subjects");
		subj = scn.nextInt();
		stud = new String[n];
		marks = new int[n][subj];
		tot = new int[n];
		highestScorer= new int[subj];
		int maxTot = 0, highScore=0;
		for (int i=0; i<n; i++) {
			System.out.println("Enter Student name.");
			stud[i] = scn.next(); 

			System.out.println("Enter "+subj+" subjects marks of "+stud[i]+" one by one.");
			for (int j=0; j<subj; j++) {
				marks[i][j] = scn.nextInt();
				tot[i] += marks[i][j];
				if (marks[highestScorer[j]][j] < marks[i][j]) {
					highestScorer[j] = i;
					//highScore = marks[i][j];
				}
			}
			if (maxTot < tot[i]) {
				maxTot = tot[i];
				totHighStud = i;
			}
		}
	}
	private void dispMarkAndTotal() {
		System.out.println("------------------------------------------------------------------------");
		System.out.println("                       STUDENTS MARK LIST                               ");
		System.out.println("------------------------------------------------------------------------");
		for (int i=0; i<stud.length; i++) {
			System.out.println("Student Name : "+stud[i]);
			for (int j=0; j<subj; j++) {
				System.out.println("Subject-"+(j+1)+" = "+marks[i][j]);
			}
			System.out.println();
			System.out.println("Total Marks = "+tot[i]);
			System.out.println("Percentage = "+(tot[i]/subj)+ "%");	
			System.out.println("------------------------------------------------------------------------");
		}
		for (int i=0; i<highestScorer.length; i++) {
			int student = highestScorer[i];
			System.out.println("Subject-"+(i+1)+" Highest Mark is "+marks[student][i]+" achieved by "+stud[student]);
		}
		System.out.println("------------------------------------------------------------------------");
		System.out.println("Over All Highest Total "+tot[totHighStud]+" achieved By "+stud[totHighStud]);
		System.out.println("------------------------------------------------------------------------");
	}
}

OUTPUT:

Address Book v1.0 as on 26thOct 2024 – (DEVELOPMENT IN PROGRESS)

Project Title : Address Book

S/w Used : HTML, CSS, JavaScript with LocalStorage for storing data (little Bootstrap)

Framework Used : Text Editor

Description : A small addressbook which is having name, email, contact no, and city which is having CRUD operations.

Till Today : Just designed the front screen for Adding New Contact – simple html screen with css only done.

<html>
<head>
 <title>Address Book</title>
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <meta name="author" content="Sugirtha">
 <meta name="description" content="Simple AddressBook with Name, Contact No, Email and City">
 <link rel="stylesheet" href="addr.css">
</head>
<body>
 <h3>Simple Address Book</h3>
 <form id="frmAddr" name="formAddr">
 <div class="container">
  <table>
   <tr>
    <th>Name</th>
    <td><input type="text" id="txtName" placeholder="Enter your Name"></td>
   </tr>
   <tr>
    <th>Email</th>
    <td><input type="text" id="txtEmail" placeholder="Enter your Email"></td>
   </tr>
   <tr>
    <th>Contact No.</th>
    <td><input type="text" id="txtPhone" placeholder="ContactNo. including ISD Code"></td>
   </tr>
   <tr>
    <th>City</th>
    <td><input type="text" id="txtCity" placeholder="Enter your City here"></td>
   </tr>
  </table>
   <div class="submitPos">
    <input type="submit" id="btnSubmit" value="SAVE" class="button">
    <input type="button" id="btnCancel" value="CLEAR" class="button">
   </div>

 </div>
 </form>
</body>
</html>

CSS

body
{
    background-color:#3d4543;
    color:white;
}
h3
{
    text-align:center;  
    font-family:Helvetica;
}
input[type=text]
{

    background-color:#bccd95;
    color:black;
    height:30px;
    width:220px;
    border-radius:3px;
    border-color:white;
}
::placeholder
{
    opacity: 1;
    font-family:Helvetica;
    font-size:15px;
}
.container 
{
    background-color:#3d4543;
    position: relative;
    top:4px;
    left:38%;
    width:450px;
    height:350px;
}
.submitPos
{
    position: relative;
    top:38px;
    left:10%;   
}
th
{
    text-align:left;
    font-family:Helvetica;
    font-size:15px;
    font-weight:bold;
}
.button
{
    position:relative;
    color:white;
    border:none;
    border-radius:3px;
    width:100px;
    height:26px;
    margin-left:10px;
    background-color:#303030; 
    border-radius:8px;
    border-bottom:black 2px solid;  
    border-top:2px 303030 solid; 
    font-family:Helvetica;
    font-size:13px;
    font-weight:bold;
}

OUTPUT

Playing with Char Array

    // 1. REMOVING UNWANTED SPACE
    // 2. CAPITALIZE EACH WORD
package taskPkg;

import java.util.Scanner;

public class PlayingWithCharAr {

	public static void main(String[] args) {
		// 1. REMOVING UNWANTED SPACE
		// 2. CAPITALIZE EACH WORD
		Scanner scn = new Scanner(System.in);
		System.out.println("Enter a sentence...");
		String sentence = scn.nextLine();
		scn.close();
		char[] sen = sentence.toCharArray();
		PlayingWithCharAr obj = new PlayingWithCharAr();
		obj.removeSpace(sen);
		obj.wordStartWithCaps(sen);
	}

	private void removeSpace(char[] words) {
		int k = 0, n = words.length;
		System.out.print("Removed unwanted spaces :");
		while (k < n && words[k] == ' ')
			k++;
		for (; k < n - 1; k++) {
			if (!(words[k] == ' ' && words[k + 1] == ' '))
				System.out.print(words[k]);
		}
		if (words[n - 1] != ' ')
			System.out.print(words[n - 1]);
		System.out.println();
	}

	private void wordStartWithCaps(char[] words) {
		int i = 0, n = words.length;
		System.out.print("Capitalize Each Word :");
		if (words[i] != ' ')
			System.out.print((char) (words[i] - 32));
		for (i = 1; i < n; i++) {
			if (words[i - 1] == ' ' && words[i] != ' ' && (words[i] >= 'a' && words[i] <= 'z'))
				System.out.print((char) (words[i] - 32));
			else
				System.out.print(words[i]);
		}
	}

}

OUTPUT:

Password Validator

import java.util.Scanner;

public class PasswordValidator {

	public static void main(String[] args) {
		// PASSWORD MUST CONTAIN MIN 8 CHARS, MAX 12 CHARS, ATLEAST 1 UPPERCASE, 1 LOWERCASE, 1 DIGIT, 1 SPL CHAR 
		Scanner scn = new Scanner(System.in);
		int maxLen = 12, minLen=8;
		System.out.println("Enter a password to validate");
		String pwd = scn.next();
		scn.close();
		int n = pwd.length();
		if (n<minLen || n>maxLen) {
			System.out.println("Password length must be between 8 to 12 characters");
			return;
		}
		char[] pw = pwd.toCharArray();
		int cntLower=0, cntUpper=0, cntDigit=0, cntSpl=0;
		for (int i=0; i<n; i++) {
			char ch = pw[i];
			if (ch>='A' && ch<='Z') cntUpper++;
			else if (ch>='a' && ch<='z') cntLower++;
			else if (ch>='1' && ch<='9') cntDigit++;
			else if (ch=='!' || ch=='Β£' || ch=='$' || ch=='%' || ch=='^' || ch=='&' || ch=='*' || ch=='-' || ch=='_' || ch=='+' || ch=='=' || ch==':' || ch==';' || ch=='@'|| ch=='#'|| ch=='~'|| ch=='>'|| ch=='<'|| ch=='?'|| ch=='.') cntSpl++; 
		}
		if (cntLower>0 && cntUpper>0 && cntDigit>0  && cntSpl>0) System.out.println("Password is valid...");
		else {
			System.out.println("Password is NOT VALID");
			System.out.println("PASSWORD MUST CONTAIN ATLEAST 1 UPPERCASE, 1 LOWERCASE, 1 DIGIT AND 1 SPL CHAR FROM ! Β£ $ % ^ & * - _ + = : ; @ ~ # ?");
		}
	}

}

Arrays Task

  1. First Letter Occurrence, Last Letter Occurrence in the given Word
  2. Print Reversed Array
  3. Cricketers array and their best score array – Give name as input and get the high score.
package taskPkg;
import java.util.Scanner;
public class ArraysBasics {
//1. PRINTING 1ST LETTER OF THE CHAR ARRAY
//2. PRINT REVERSED A CHAR ARRAY	
//3. 
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ArraysBasics obj = new ArraysBasics();
		Scanner scn = new Scanner(System.in);
		System.out.println("Enter a name to find its first and Last Letter.");
		String nam =  scn.next();
		char[] name = nam.toCharArray();
		System.out.println("First Letter of "+nam+" is repeated at "+obj.findFirstLtr(name));
		System.out.println("Last Letter of "+nam+" is repeated at "+obj.findLastLtr(name));
		obj.printReversedArray(name);
		System.out.println();  
		
		String[] cricketers = {"Rohit","Suryakumar","Ashwin", "Jadeja","Yashasvi"}; 
		int[] scores = {100,120,86,102,98};
		System.out.println("Enter one cricketer name to get his high score");
		String givenName = scn.next();
		System.out.println("Score for " + givenName+  " is "+obj.getScore(cricketers,scores,givenName));
		
		
	}
	private int findFirstLtr(char name[]) {
		char ch = name[0];
		for (int i=1; i<name.length; i++) {
			if (ch==name[i]) return i;
		}
		return -1;
	}
	private int findLastLtr(char name[]) {
		char ch = name[name.length-1];
		for (int i=0; i<name.length-1; i++) {
			if (ch==name[i]) return i;
		}
		return -1;
	}
	private void printReversedArray(char[] name) {
		System.out.println("Reversed Array = ");
		for (int i=name.length-1; i>=0; i--) {
			System.out.println(" "+name[i]);
		}
	}
	private int getScore(String[] name, int[] score, String givenName) {
		int n = name.length;
		for(int i=0; i<n; i++) {
			if(name[i].equals(givenName)) return score[i];
		}
		return 0;
	}
	
}

OUTPUT:

CALCULATOR

<html>
<head>
    <title>Simple Calculator</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="author" content="Sugirtha">
    <meta name="description" content="Calculator using HTML, CSS, JavaScript">   
    <link rel="stylesheet" href="calc.css">
</head>
<body>
    <h2 align="center">CALCULATOR</h2>
<div class="borderContainer">
<div class="container" >
<div class="resultsContainer" ><input type="text" id="results" name="results" class="result" readonly></div>
<div class="numPadContainer">
    <p>
    <input type="button" value="7" class="button black" onclick='calc("7")'>
    <input type="button" value="8" class="button black" onclick='calc("8")'>
    <input type="button" value="9" class="button black" onclick='calc("9")'>
    <input type="button" value="/" class="button opr" onclick='calc("/")'>
    </p>
    <p>
    <input type="button" value="4" class="button black" onclick='calc("4")'>
    <input type="button" value="5" class="button black" onclick='calc("5")'>
    <input type="button" value="6" class="button black" onclick='calc("6")'>
    <input type="button" value="*" class="button opr" onclick='calc("*")'>
   </p>
    <p>
    <input type="button" value="1" class="button black" onclick='calc("1")'>
    <input type="button" value="2" class="button black" onclick='calc("2")'>
    <input type="button" value="3" class="button black" onclick='calc("3")'>
    <input type="button" value="-" class="button opr" onclick='calc("-")'>
    </p>
    <p>
    <input type="button" value="0" class="button black" onclick='calc("0")'>
    <input type="button" value="00" class="button black" onclick='calc("00")'>
    <input type="button" value="." class="button black" onclick='calc(".")'>
    <input type="button" value="+" class="button opr" onclick='calc("+")'>

    </p>
    <p>
    <input type="button" value="mod" class="button opr" onclick='calc("%")'>
    <input type="button" value="C" class="button red" onclick='results.value=""'>
    <input type="button" value="=" class="button orange" onclick='doOper()' >

   </p>
</div>
</div>
</div>
<script>
    var answered=false;
    function calc(val) 
    {
        optrs = "+-*/%"
        if (answered && !optrs.includes(val)) 
        {
         
                //alert("not included opr - clearing ans")
                document.getElementById("results").value="";
                
            
        }
        document.getElementById("results").value += val;
        answered=false;
    }
    function doOper()
    {
        try
        {
            dispAns(eval(document.getElementById("results").value));
            
        }
        catch
        {
            dispAns("Input Error");
        }
    }
    function dispAns(output) 
    {
        document.getElementById("results").value = output;
        answered=true;
    }

</script>
</body>
</html>
body 
{
    background-color:black;
    color:lightgrey;
}



.borderContainer 
{
    position:relative;
    top:10px;
    left:36%;
    width:370;
    height:500;
    background-color: lightgrey;
}
.container
{
    position:relative;
    left:8%;
    top:25px;
    width:310px;
    height:450px;
    background-color:#3d4543;
    border-radius:3px;
}
.numPadContainer
{
    position:relative;
    left:25px;
    top:40px; 
}
.result
{
    position:relative;
    left:24px;
    top:28px;
    background-color:#bccd95;
    color:black;
    text-align:right;
    height:40px;
    width:260px;
    border-radius:10px;
    border-color:white;
}
.button
{
    position:relative;
    color:white;
    border:none;
    border-radius:8px;
    cursor:pointer;
    width:48px;
    height:42px;
    margin-left:10px;
}
.button.black
{
    background-color:#303030; 
    border-radius:8px;
    border-bottom:black 2px solid;  
    border-top:2px 303030 solid; 
}
.button.red
{
    background-color:#cf1917;  
    border-bottom:black 2px solid; 
    font-weight:bold;
}
.button.opr
{
    background-color:grey;  
    border-bottom:black 2px solid; 

}
.button.orange
{
    background-color:orange;
    border-bottom:black 2px solid;
    width:110px;
    font-weight:bold;
}

OUTPUT:

Pattern Printing – Others

public class Patterns {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//PRINTING 1's and 0's IN SPECIFIC PATTERN
		int n=5;
		Patterns ptn = new Patterns();
		ptn.pattern1(n);
		System.out.println();
		ptn.pattern2(n);
		System.out.println();
		ptn.pattern3("SUGIRTHA");
	}
	private void pattern1(int n) {
		int val=0;
		for (int r=1; r<=n; r++) {
			val = r%2==0?0:1;
			for (int c=1; c<=n-r+1; c++) {
				System.out.print(" "+val);
				val=1-val;
			}
			System.out.println();
		}
	}
	private void pattern2(int n) {
		int val=1;
		for (int r=1; r<=n; r++) {
			for (int c=1; c<=n-r+1; c++) {
				System.out.print(" "+val);
			}
			val=1-val;
			System.out.println();
		}
	}
	private void pattern3(String name) {
		int n = name.length();
		for (int r=1; r<=n; r++) {
			for (int c=0; c<r; c++) {
				System.out.print(" "+name.charAt(c));  //TBD 
			}
			System.out.println();
		}
	}

}

OUTPUT:

Patterns – Printing Numbers 0-9

package taskPkg;

public class PatternsPrintNos {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		PatternsPrintNos ptnNos = new PatternsPrintNos();
		int n=9;
		for (int i=0; i<=9; i++) {
			ptnNos.printNo(i,n);
			System.out.println();
		}
	}
	private void printNo(int num, int n) {
		int m=n/2+1;
		switch(num) {
		case 0:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || r==n || c==1 || c==n) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;			
		case 1:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (c==m) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 2:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || r==n || r==m || (r<=m && c==n) || (c==1 && r>=m)) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 3:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || r==n || r==m || c==n) System.out.print(" *"); 
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 4:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if ((c==1 && r<=m) || c==m ||  r==m ) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 5:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || r==n || r==m || (r<=m && c==1) || (c==n && r>=m)) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 6:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (c==1  ||  r==n || r==m || (r>m && c==n)) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 7:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || (c==n-r+1)) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;
		case 8:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || r==m || r==n || c==1 || c==n) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;		
		case 9:
			for (int r=1; r<=n; r++) {
				for (int c=1; c<=n; c++) {
					if (r==1 || r==m || (c==1 && r<=m) || c==n) System.out.print(" *");
					else  System.out.print("  ");
				}
				System.out.println();
			}
			break;				
		}

	}
}

Output:

Patterns – Printing Name

public class PatternMyName {
	//  MY NAME - IN PATTERN PRINTING

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		PatternMyName pattern = new PatternMyName();
		int n=9;
		pattern.printLtr("S",n);
		pattern.printLtr("U",n);
		pattern.printLtr("G",n);
		pattern.printLtr("I",n);
		pattern.printLtr("R",n);
		pattern.printLtr("T",n);
		pattern.printLtr("H",n);
		pattern.printLtr("A",n);
	}
	private void printLtr(String ltr,int n) {
		int m=n/2 +1;
		switch(ltr) {
			case "S":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if (r==1 || r==n || r==m || (c==1 && r<m) || (c==9 && r>m)) {
							if ((c==1 && r==1) || (r==n && c==n) || (r==m && (c==1 || c==n))) System.out.print("  ");
							else System.out.print(" *");
						}
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;
				
			case "U":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ((c==1 && r<n)|| (c>1 && c<n && r==n) || (r<n && c==n))
								System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;
			
			case "G":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ((r==1 && c!=1) || (c==1 && r!=1 && r!=n) || (r==n && c!=1 && c!=n) || (c==n && r>=m && r!=n) || (r==m && c>m)) System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;

			case "I":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ( c==m || r==1 || r==n) System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;
				
			case "R":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ( (c==1 && r!=1) || (r==1 && c!=n && c!=1) || (c==n && r<m && r!=1) || (r==m && c!=n) || (r>m && c==m+(r-m))) System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;
				
			case "T":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ( c==m || r==1 ) System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;
				
			case "H":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ( c==1 || c==n || r==m) System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;
			
			case "A":
				for (int r=1; r<=n; r++) {
					for (int c=1; c<=n; c++) {
						if ( (r<=m && (c==m-r+1 || c==m+r-1)) || r==m || (r>m && (c==1 || c==n))) System.out.print(" *");
						else System.out.print("  ");
					}
					System.out.println();
				}
				System.out.println();
				break;

		}
	}
}

OUTPUT:

Task – For Loop – Playing with Numbers

Armstrong, Neon, Perfect, Prime, emirP, Strong, Triangle Series
import java.util.Scanner;

public class forLoopPlayWithNos {
// USING FOR LOOP
//Code for Armstrong, Neon, Perfect, Prime, emirP, Strong Numbers
// Factorial, SumOfDigits, ReverseDigits, CountOfDigits, Power also used.
//Triangular Series : 1,3,6,10,15,21,28,....
	    // FOR PRINTING 
		private static void print(int n, String numType, boolean matched) {
			if (matched) System.out.println(n+"  is a " + numType +" Number.");
			else System.out.println(n+"  is not a " + numType +" Number.");
		}

		public static void main(String[] args) {
			// TODO Auto-generated method stub
			forLoopPlayWithNos loop = new forLoopPlayWithNos();
	        System.out.print("Enter a Number to Play = ");
	        Scanner scn = new Scanner(System.in);
	        int num = scn.nextInt();
	        scn.close();
			
	        forLoopPlayWithNos.print(num, "ArmStrong",loop.isArmstrongNo(num));
	        forLoopPlayWithNos.print(num, "Neon", loop.isNeonNo(num));
	        forLoopPlayWithNos.print(num, "Perfect",loop.isPerfectNo(num));
	        forLoopPlayWithNos.print(num, "Prime",loop.isPrimeNo(num));
	        forLoopPlayWithNos.print(num, "emirP",loop.isemirPNo(num));
	        forLoopPlayWithNos.print(num, "Strong",loop.isStrong(num));
			loop.tringangularSeries(num);
		}
		
		private boolean isArmstrongNo(int n) {
			//Sum of (each digit to the power of (No of digits)) == n
			// Ex. 371, 153 == 1^3 + 5^3 + 3^3 = 1+125+27
			int powSum=0, nod = countDigits(n);
			for (int num=n; num>0; num/=10) {
				powSum += findPower((num%10),nod);
			}
			if (n == powSum) return true;
			return false;
		}
		
		private boolean isNeonNo(int n) {
			//Neon = (Sum of digits of a squared number == number)
			// Ex 1,9,45,55
			int sqNum = n*n;
			if (n == sumOfDigits(sqNum)) return true;
			return false;
		}
		
		private boolean isPerfectNo(int n) {
			//Sum of its divisors (excluding n) == n
			//Ex. 6,28,496
			int sum=1;
			for(int i=2; i<n; i++) {
				if (n%i == 0) sum+=i; // Adding Divisors
			}
			if (sum==n) return true;
			return false;
		}
		
		private boolean isPrimeNo(int n) {
			// N number that can be divided exactly only by itself, ie n's divisors are 1 and n
			// Ex 2,3,5,7,11,13
			switch(n) {
			case 0,1:
				return false;
			case 2,3:
				return true;
			default:
				if (n%2 == 0) return false;
				else {
					for (int i=3; i*i<n; i+=2) {
						if (n%i == 0) {
							return false;
						}
					}
				}
			}
			return true;
		}
		
		private boolean isemirPNo(int n) {
			// A number and revereDigits of that number are prime
			int rev = reverseDigits(n);
			return (isPrimeNo(n) && isPrimeNo(rev))? true:false;
		}
		
		private boolean isStrong(int n) {
			//sum of the factorial of its digit is equal to number itself
			// Ex. 145 = 1!+4!+5!
			int sum = 0, num=n;
			for (num=n; num>0; num/=10) {
				sum += factorial(num%10);
			}
			return (n == sum)? true:false; 
		}
		
		private int findPower(int base, int pr) {
			// finding base to the power pr
			int res=1;
			for (; pr>=1; pr--) {
				res *= base;
			}
			return res;
		}
		
		private int reverseDigits(int num) {
			int rev = 0;
			for (; num>0; num/=10) {
				rev = rev*10 + num%10;
			}
			return rev;
		}
		private int countDigits(int num) { //Counting No. of Digits
			int cnt=0;
			for (; num>0; num/=10,cnt++); 
			return cnt;
		}
		private int sumOfDigits(int n) {
			int sum=0;
			for (; n>0; n/=10) {
				sum += n%10;
			}
			return sum;
		}
		
		private int factorial(int n) {
			int fact=1;
			for (int i=1; i<=n; i++) {
				fact *= i;
			}
			return fact;
		}	
		
		private void tringangularSeries(int n) {
			System.out.print("Tringangular Series : ");
			for (int tri=1, i=2; tri<=n; i++) {
				System.out.print(tri+" ");
				tri+=i;
			}
		}
}

OUTPUT:

Task – While Loop – Armstrong, Neon, Perfect, Prime, emirP, Strong

package taskPkg;

import java.util.Scanner;
public class PlayingWithNumbers {
//Code for Armstrong, Neon, Perfect, Prime, emirP, Strong Numbers
// Factorial, SumOfDigits, ReverseDigits, CountOfDigits, Power also used.
    	// FOR PRINTING 
	private static void print(int n, String numType, boolean givenNumType) {
		if (givenNumType) System.out.println(n+"  is a " + numType +" Number.");
		else System.out.println(n+"  is not a " + numType +" Number.");
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		PlayingWithNumbers loop = new PlayingWithNumbers();
        System.out.print("Enter a Number to Play = ");
        Scanner scn = new Scanner(System.in);
        int num = scn.nextInt();
        scn.close();
		

		PlayingWithNumbers.print(num, "ArmStrong",loop.isArmstrongNo(num));
		PlayingWithNumbers.print(num, "Neon", loop.isNeonNo(num));
		PlayingWithNumbers.print(num, "Perfect",loop.isPerfectNo(num));
		PlayingWithNumbers.print(num, "Prime",loop.isPrimeNo(num));
		PlayingWithNumbers.print(num, "emirP",loop.isemirPNo(num));
		PlayingWithNumbers.print(num, "Strong",loop.isStrong(num));
		
	}
	
	private boolean isArmstrongNo(int n) {
		//Sum of (each digit to the power of No of digits) == n
		int num=n, powSum=0, nod = countDigits(num);
		while (num > 0) {
			powSum += findPower((num%10),nod);
			num/=10;
		}
		if (n == powSum) return true;
		return false;
	}
	
	private boolean isNeonNo(int n) {
		//Neon = (Sum of digits of a squared number == number)
		int sqNum = n*n;
		if (n == sumOfDigits(sqNum)) return true;
		return false;
	}
	
	private boolean isPerfectNo(int n) {
		//Sum of its divisors (excluding n) == n
		int i=2, sum=1;
		while (i<n) {
			if (n%i == 0) sum+=i; // Adding Divisors
			i++;
		}
		if (sum==n) return true;
		return false;
	}
	
	private boolean isPrimeNo(int n) {
		// N number that can be divided exactly only by itself, ie n's divisors are 1 and n
		if (n<=1 || n%2 == 0) return false;
		if (n<=3) return true;
		int i=3;
		while (i < n) {
			if (n%i == 0) {
				return false;
			}
			i+=2;
		}
		return true;
	}
	
	private boolean isemirPNo(int n) {
		// A number and revereDigits of that number are prime
		int rev = reverseDigits(n);
		return (isPrimeNo(n) && isPrimeNo(rev))? true:false;
	}
	
	private boolean isStrong(int n) {
		//sum of the factorial of its digit is equal to number itself
		// Ex. 145 = 1!+4!+5!
		int sum = 0, num=n;
		while (num>0) {
			sum += factorial(num%10);
			num/=10;
		}
		return (n == sum)? true:false; 
	}
	
	private int findPower(int base, int pr) {
		// finding base to the power pr
		int res=1;
		while (pr>=1) {
			res *= base;
			pr--;
		}
		return res;
	}
	
	private int reverseDigits(int num) {
		int rev = 0;
		while (num>0) {
			rev = rev*10 + num%10;
			num/=10;
		}
		return rev;
	}
	private int countDigits(int num) { //Counting No. of Digits
		int cnt=0;
		while (num>0) {
			num/=10;
			cnt++;
		}
		return cnt;
	}
	private int sumOfDigits(int n) {
		int sum=0;
		while (n>0) {
			sum += n%10;
			n/=10;
		}
		return sum;
	}
	
	private int factorial(int n) {
		int i=1,fact=1;
		while (i<=n) {
			fact *= i;
			i++;
		}
		return fact;
	}	

}


Output:

IRC – Internet Relay Chat

What is IRC?

IRC stands for Internet Relay Chat. Its simply text messaging service (real time online communication service) and even with hundreds of people at once in fractions of a second messages are getting shared.

  • Actually it is a protocol for real-time text messaging created. It is mainly used for group discussion between the like minded people in chat rooms called β€œchannels” (Ex. #Kaniyam) although it supports private messages between two users.
  • Mainly this is used in lots of open source community knowledge share – Ex. If you want to chat with a developer from linux, firefox etc.
  • The Chat Process works on a client-server networking model.

Wait! Wait!! Is it a Protocol or Chat App?

Its a Protocol which is implemented in client server for the text chat. WeeChat is one of the terminal application for IRC client and Pidgin is one of the Desktop client app.

Founder & Year :

IRC was developed in 1988 by Jakko Oikarinen in Finland

Merits/Advantages :

Simplicity : IRC is a simple, text-based environment for communication, without the multimedia features of other platforms.Β 

Community building : IRC is ideal for interest-based or topic-based chat rooms, and is designed to foster a sense of community

Decentralized : IRC isn’t controlled by a single company, so anyone can set up their own server and network.Β 

Privacy : Users can control their privacy with access levels, invitation-only channels, and one-on-one messaging.Β 

Accessibility : IRC is accessible across various platforms, including desktop, laptop, and mobile devices.

Speed : IRC is a good option for fast text-based chat apps with a geographically distributed user-base, as it has low latency and can transmit large amounts of data quickly. (Simply its all texts – so speed is high).

Flexibility : IRC can be used for a variety of purposes, from critical operations to gaming discussions.Β 

File sharing : IRC clients can be used to create file servers and share files with other users.Β 

Everything is Fine, But already we have so many Apps for Chats, Why IRC?

So many People have so many answers, but according to me,

Reading is a Best Habit compares to watching video (unless it is necessary). It will increase our imagination capacity. Imagination is the key factor for our more technologies and inventions.

Environmental friendly – We are making so much of carbon footprints everyday. A carbon footprint is the total amount of greenhouse gases (including carbon dioxide and methane) that are generated by our actions.

We are wasting so much of energy (electricity and other resources) while sharing tons of files or images or videos everyday.

I am not asking you to stop watching TV or using internet etc…

Why don’t you contribute to our Mother Earth at least by doing this simple help.

I want to Know More about IRC :

Thanks Note: My sincere Thanks to our Professor Mr. MuthuRamaLingam and Mr. Shrini

❌