DEV Community: Saravanan

Matrix Addition,Matrix Multipliction

Saravanan — Tue, 04 Mar 2025 16:57:02 +0000

1.Matrix Addition:

public static void main(String[] args) {

int[][] a= {{1,2,3}
            {1,2,3},
        {4,5,6}};

int[][] b= {{6,7,8},
        {1,2,3},
        {7,8,9}};
int [][] c=new int[a.length][a[0].length]; 

for(int row=0;row<a.length;row++)
{
    for(int col=0;col<b.length;col++)
    {   
      c[row][col]=a[row][col]+b[row][col];
      System.out.print(c[row][col]+" ");
    }
      System.out.println();
}

}

output:
7 9 11
2 4 6
11 13 15

2.Martix Multipliction:

public static void main(String[] args) {

int[][] a= {{1,2,3},
        {1,2,3},
        {4,5,6}};
int[][] b= {{6,7,8},
        {1,2,3},
        {7,8,9}};
int [][] c=new int[a.length][a[0].length];
for(int row=0;row<a.length;row++)
{
  for(int col=0;col<b.length;col++)
  {
    for(int k = 0;k<b.length;k++)
    {
      c[row][col]=c[row][col]+(a[row][k]*b[k][col]);
    }
    System.out.print(c[row][col]+" ");
  }
     System.out.println();
}

}

output:
29 35 41
29 35 41
71 86 101

Linear search and Binary search programs

Saravanan — Mon, 24 Feb 2025 17:42:49 +0000

Linear Search:

int[] ar = {10,45,67,100}       
int key = 67;
for(int i=0;i<ar.length;i++)
{
 if(ar[i]==key)
 System.out.println("key is presented :"+i);
}

output:
key is presented :2

Binary Search:


int[] ar = {10,16,18,21,27,37, 45, 98,100};
int key = 18;
int max_idx = ar.length-1;
int min_idx=0;
while(min_idx<=max_idx)
{
    int mid_idx=(min_idx+max_idx)/2;        
    if(ar[mid_idx]==key)            

    {
        System.out.println("key is present :" + mid_idx);
        break;
    }
    else if(key>ar[mid_idx])    
    {
        min_idx= mid_idx+1;
    }
    else if(key<ar[mid_idx]) 
    {
        max_idx= mid_idx-1;     
    }


}

output:
key is present :2

While loop examples

Saravanan — Thu, 06 Feb 2025 17:03:36 +0000

(1)

                int count = 0;
        while(count<5)
        {
            System.out.println("1 2 3 4 5");
            count = count + 1;
        }

//      output:1 2 3 4 5
//             1 2 3 4 5
//             1 2 3 4 5
//             1 2 3 4 5 
//             1 2 3 4 5

(2)

                int count = 1;
        while (count <=5)
        {
            System.out.println("1 0 1 0 1");
            count = count + 1;
        }

//      output:1 0 1 0 1
//             1 0 1 0 1
//             1 0 1 0 1
//             1 0 1 0 1
//             1 0 1 0 1

(3) - Chocolate

                int chocolate = 15;
        int wrapper = 15;
        while (wrapper >=3)
        {
            wrapper = wrapper - 3;
            chocolate = chocolate + 1;
            wrapper = wrapper + 1;

        }
        System.out.println(chocolate);

//      output: 22

(4) - Dosai count

                int total_balance = 8;
        int count = 1;
        while(count<=3)
        {
        int dosai_count =total_balance/2;
        total_balance = total_balance + dosai_count;
        count = count + 1;
        }
        {
        System.out.println(total_balance);
        }

//      output: 27

(5) - 3 tables

int no = 1;
        int count = 1;
        while(no<=10)
        {
        int j = no*3;
        System.out.println(no +"*"+3+"="+j);
        no = no+ 1;
        count = count + 1;
        }

//      output: 1*3=3
//              2*3=6
//              3*3=9
//              4*3=12
//              5*3=15
//              6*3=18
//              7*3=21
//              8*3=24
//              9*3=27
//              10*3=30

Control flow statement: while loop.

Saravanan — Wed, 29 Jan 2025 13:26:26 +0000

loops:

-Loops can execute a block of code as long as a specified condition is reached.
-Loops are handy because they save time, reduce errors, and they make code more readable.

while loop:

A while loop in Java is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The loop continues to execute as long as the condition evaluates to true.

syntax:

while (condition) {
// code block to be executed
}

task 1:

/*
                int count = 0;
                while(count<=5)
                {                                       //Output:1 1 1 1 1
                    System.out.println(1);
                    count = count + 1;
                }
                */

task 2:

 /*
                int count = 5;
                while(count>=1)
                {                                         //Output:5 4 3 2 1 
                    System.out.println(count);
                    count = count - 1;
                }
                */

key point:

-The loop runs zero or more times, depending on the condition.
-If the condition is false at the start, the loop does not execute.
-If the condition never becomes false, an infinite loop occurs.

Examples for condition statement,if,if else,else if

Saravanan — Wed, 29 Jan 2025 13:07:12 +0000

```package program_basics;

public class Condition_statement {

public static void main(String[] args) {
    // TODO Auto-generated method stub

//-------------------------------------------------
//if only
/*
int i=25;
int j=50;

    if (i<j)
    {
        System.out.println("j is greater");

    }
    */

//-----------------------------------------------
//if else only
/*
int i=25;
int j=50;

    if (i>j)
    {
        System.out.println("j is greater");

    }
    else 
    {
        System.out.println("j is lesser");

    }
    */

//----------------------------------------------------

//else if only
/*
int i=35;
int j=50;

    if (i>j)
    {
        System.out.println("i is greater");
    }
    else if(j<i)
    {
        System.out.println("j is greater");
    }
    else
    {
        System.out.println("this is false");
    }
    */
}

}

Day-5 Example for Encapsulation

Saravanan — Wed, 18 Dec 2024 15:23:26 +0000

public class Friend1
{
String name;
long mobileNo; 
private int atmPin; 

public Friend1(String name, long mobileNo, int atmPin)
{
this.name = name; 
this.mobileNo = mobileNo; 
this.atmPin = atmPin; 
}

public static void main(String[] args)
{
Friend1 f1 = new Friend1("Kavin", 1234, 1111);
f1.withdraw();

}
private void withdraw()
{
System.out.println(atmPin);
}
public void tour()
{
System.out.println("Going for a ride");
}

public void publish_results()
{
System.out.println("Pass with good marks ");
}




}

class Friend2
{

public static void main(String[] args)
{

Friend1 ff = new Friend1("Arul",3434,2323);
ff.tour();
ff.withdraw();
}

}

output:

Day-4 Task-2

Saravanan — Wed, 18 Dec 2024 05:06:51 +0000

Task:

Create a class Called PlayGround
Create non-static variables as below. int score, balls, catches; String player_name;
Create main method.
Inside main method, create two instances as below. PlayGround player1 = new PlayGround("dhoni", 100, 3); PlayGround player2 = new PlayGround("jadeja", 56, 2, 30);
Create appropriate constructors for handling above objects.
Using player1 object, call batting() method. Print - score, player_name.
Using player2 object, call allrounder() method. Print - score, player_name, balls, catches

class PlayGround
{
    int score,balls,catches;
    String player_name;

    public PlayGround(String player_name,int score,int catches)
    {
        this.score = score;
        this.player_name = player_name;
        this.catches = catches;
    }
    public PlayGround(String player_name,int score,int catches,int balls)
    {
        this.score = score;
        this.balls = balls;
        this.catches = catches;
        this.player_name = player_name;
    }

    public static void main(String [] args)
    {
        PlayGround player1 = new PlayGround("dhoni",100,3);
        PlayGround player2 = new PlayGround("jadeja",56,2,30);

        player1.batting();
        player2.allrounder();
    }
    public void batting()
    {
    System.out.println(player_name +" "+ score);
    }
    public void allrounder()
    {
    System.out.println(player_name + " " + balls + " " + score + " " + catches);
    }
}

Output:

Day - 4 Task-1

Saravanan — Tue, 17 Dec 2024 04:58:59 +0000

class Employee
{
    public static void main(String[] args)
    {
        Employee emp=new Employee();
        emp.develop();
        int output = emp.work(10);
        System.out.println("work" + " " + output ); 
    }

       public void develop()
    {

    }
       public int work(int e)
    {
        return e * 10;
    }

output:

Day-3 simple return model

Saravanan — Tue, 10 Dec 2024 15:08:39 +0000



class Bmw
{
public static void main(String args[])
{

Bmw car = new Bmw();
car.go_to_race();

}
public  int go_to_race()
{
System.out.println("we are going to race");
  return 700000;
}
}

- 

out put:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/5o17j5q39shuo7s4ec34.png)

Day-3 What is Datatype?

Saravanan — Tue, 10 Dec 2024 14:38:48 +0000

Day-3 What is mean by Method overloading?

Saravanan — Tue, 10 Dec 2024 14:25:09 +0000

Day 2 Task-1 Theatre.java

Saravanan — Tue, 10 Dec 2024 06:12:20 +0000

out put: