Java Practice1

abstract class Shape
{
int x,y;
void getdata(int x1,int y1)
{
x=x1;
y=y1;
}
abstract void area();
}
class Rectangle extends Shape
{
void area()
{
int a=x*y;
System.out.println("Area of Rectangle having width"+x+"and Height="+y+"is"+a);
}
}
class Triangle extends Shape
{
void area()
{
int a=(x*y)/2;
System.out.println("Area of Triangle="+a);
}
}
class AbstractDemo
{
public static void main(String arg[])
{
Rectangle r=new Rectangle();
r.getdata(20,10);
r.area();
Triangle t=new Triangle();
t.getdata(30,40);
t.area();
}
}import javax.swing.JOptionPane;
public class activity11
{
public static void main(String args[])
{
int a,b,c,d,x;
a=Integer.parseInt(JOptionPane.showInputDialog("First Number"));
b=Integer.parseInt(JOptionPane.showInputDialog("Second Number"));
d=Integer.parseInt(JOptionPane.showInputDialog("Number Sequence"));
c=0;
System.out.print(a);
System.out.print(" "+b);
 for (x=0;x<=d-2;x++)
 {
 c=a+b;
 System.out.print(" "+c);
 a=b;
 b=c;
 }  
}
}import java.io.*;
import java.lang.*;
class add
{
public static void main(String args[])throws IOException
{
DataInputStream in = new DataInputStream(System.in);
int a=0;
a = Integer.parseInt(in.readLine());
int d = a+a;
System.out.println(d);
}
}import java.io.*;

class animate
{
        public static void main(String args[])
        {
        String msg="Java At RNEC by RVS..";
        Thread t=Thread.currentThread();
        try
        {
                for(;;)
                {
                msg=msg.substring(1,msg.length())+String.valueOf(msg.charAt(0));
                System.out.println(msg);
                t.sleep(100);              
                }
        }
        catch(Exception e)
        {
        e.printStackTrace();
        }

        }
}





import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.io.*;
import java.lang.*;

/*


*/

public class appcal extends Applet implements ActionListener
{

Button b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14;

TextField t1;

String str,str1,str3;
int n1,n2,n3;
String str2=0 + "";

public void init()
{
setLayout(null);
t1 = new TextField(20);

b0 = new Button("0");
b1 = new Button("1");
b2 = new Button("2");
b3 = new Button("3");
b4 = new Button("4");
b5 = new Button("5");
b6 = new Button("6");
b7 = new Button("7");
b8 = new Button("8");
b9 = new Button("9");
b10 = new Button("+");
b11 = new Button("-");
b12 = new Button("*");
b13 = new Button("/");
b14 = new Button("=");


add(t1);
add(b0);
add(b1);
add(b2);
add(b3);
add(b4);
add(b5);
add(b6);
add(b7);
add(b8);
add(b9);
add(b10);
add(b11);
add(b12);
add(b13);
add(b14);


b0.addActionListener(this);
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
b4.addActionListener(this);
b5.addActionListener(this);
b6.addActionListener(this);
b7.addActionListener(this);
b8.addActionListener(this);
b9.addActionListener(this);
b10.addActionListener(this);
b11.addActionListener(this);
b12.addActionListener(this);
b13.addActionListener(this);
b14.addActionListener(this);


t1.setBounds(100,100,200,30);

b1.setBounds(100,150,50,50);
b2.setBounds(150,150,50,50);
b3.setBounds(200,150,50,50);
b4.setBounds(250,150,50,50);

b5.setBounds(100,200,50,50);
b6.setBounds(150,200,50,50);
b7.setBounds(200,200,50,50);
b8.setBounds(250,200,50,50);

b9.setBounds(100,250,50,50);
b0.setBounds(150,250,50,50);
b10.setBounds(200,250,50,50);
b11.setBounds(250,250,50,50);

b12.setBounds(100,300,50,50);
b13.setBounds(150,300,50,50);
b14.setBounds(200,300,50,50);
/*b2.setBounds(250,300,50,50);

b2.setBounds(150,150,50,50);


*/}

public void actionPerformed(ActionEvent e)

{

str1 = e.getActionCommand();

if(str1.equals("0"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("1"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("2"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("3"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("4"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("5"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("6"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("7"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("8"))
{
str2 = str2 + str1;
t1.setText(str2);
}
if(str1.equals("9"))
{
str2 = str2 + str1;
t1.setText(str2);
}

if(str1.equals("+"))
{
str = 0 +"";
str = t1.getText();
n1 = Integer.parseInt(str);
str3 = str1;
str2 = "";
}
if(str1.equals("-"))
{
n1 = Integer.parseInt(str2);
str3 = str1;
str2 = "";
}
if(str1.equals("*"))
{
n1 = Integer.parseInt(str2);
str3 = str1;
str2 = "";
}
if(str1.equals("/"))
{
n1 = Integer.parseInt(str2);
str3 = str1;
str2 = "";
}

if(str1.equals("="))
{
str2 = t1.getText();
n2 = Integer.parseInt(str2);

if(str3.equals("+"))
{
n3 = n1 + n2;
}
if(str3.equals("-"))
{
n3 = n1 + n2;
}
if(str3.equals("*"))
{
n3 = n1 + n2;
}
if(str3.equals("/"))
{
n3 = n1 + n2;
}
str3 = n3 + "";
t1.setText(str3);
}


}
}public class AppendAndInsertStringsDemo {
public static void main(String args[ ]) {
StringBuffer sb = new StringBuffer(30);
sb.append("Sofia Bulgaria.");
sb.insert(6, "is capital of ");
System.out.println(sb.toString());

String str = String.valueOf(Math.PI);
System.out.println("This is the string representation of " + str);
Float pi = Float.valueOf(str);
System.out.println("This is the number representation of " + pi);
}
}
import java.awt.*;
import java.applet.*;

public class applt extends java.applet.Applet
{

public void init()
{
    resize(250,250);
}

public void paint(Graphics g)
{
Font myfont=new Font("Times new roman",Font.BOLD + Font.ITALIC,25);
g.setFont(myfont);
g.drawRect(100,100,300,450);
g.setColor(Color.orange);
g.fillRect(100,100,30,50);
g.setColor(Color.red);
g.drawString("hello world",120,120);
g.drawRect(100,100,300,450);
g.setColor(Color.green);
g.fillRect(150,150,30,50);

}
}
   













import java.applet.*;
import java.awt.*;
import java.awt.event.*;

class actlstn implements ActionListener
{
        public void actionPerformed(ActionEvent e)
        {
        int ctr=1,no=0,fact=1;
        Button bt;
        bt=(Button)e.getSource();
        if((bt.getLabel()).equals("compute"))
        {
        no=Integer.parseInt(appltfact.t1.getText());
        while(ctr<=no)

        {
        fact*=ctr;
        ctr++;
        }
        appltfact.t2.setText(String.valueOf(fact));
        }
        System.out.println("....");
        }
}
public class appltfact extends Applet
{
        static TextField t1,t2;
        Label l1,l2;
        Button b;
        public void init()
        {
        l1=new Label("enter an integer.");
        l2=new Label("fatorial val:");
        t1=new TextField();
        t2=new TextField(" ");
        b=new Button("compute");
        add(l1);
        add(t1);
        add(l2);
        add(t2);
        b.addActionListener(new actlstn());
        add(b);
        setSize(300,400);
        setVisible(true);
        }
      public void paint(Graphics g)
      {
      showStatus("computing Factorial value...");
      }
}

/*


*/
import java.applet.*;
import java.awt.Graphics;
import java.awt.TextField;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;
import java.awt.Panel;

class mmlstn implements MouseMotionListener
{
public void mouseDragged(MouseEvent m)
{
}
public void mouseMoved(MouseEvent m)
{
int x,y;
x=m.getX();
y=m.getY();
appltmouse.t.setText(String.valueOf(x)+" , "+String.valueOf(y));
}

}

public class appltmouse extends Applet
{
static TextField t;
public void init()
{
t=new TextField("........");
Panel p=new Panel();
p.add(t);
add(p);
//mouse event deligation
addMouseMotionListener(new mmlstn());
setSize(300,400);
setVisible(true);
}
public void paint(Graphics g)
{
g.drawRect(20,20,200,150);
}
}
/*


*/


import java.io.*;
class area
{
int x;
double y;

void cal(double pi,int ra)
{
y = pi*ra*ra;
System.out.println("Circle area is\t:"+y);
}
void cal(int len)
{
x = len*len;
System.out.println("Squre area is\t:"+x);
}
void cal(int len,int br)
{
x = len*br;
System.out.println("Rectangle area is\t:"+x);
}
}
class area1
{
public static void main(String args[])throws IOException
{
DataInputStream in = new DataInputStream(System.in);
System.out.print("choose any one \t 1.CIRCLE \t 2.SQURE \t 3.RECTANGLE\t:");
int a = Integer.parseInt(in.readLine());
area A = new area();
if(a==1)
{
System.out.print("Enter the radius\t:");
int b = Integer.parseInt(in.readLine());
A.cal(3.14,b);
}
else if(a==2)
{
System.out.print("Enter the length\t:");
int c = Integer.parseInt(in.readLine());
A.cal(c);
}
else
{
System.out.print("Enter the length\t:");
int d = Integer.parseInt(in.readLine());
System.out.print("Enter the breath\t:");
int e = Integer.parseInt(in.readLine());
A.cal(d,e);
}
}
}import java.io.*;
import java.lang.*;
class areae extends Exception
{
areae(String msg1)
{
super(msg1);
}
}
class area
{
int x;
double y;

void cal(double pi,int ra)
{
y = pi*ra*ra;
System.out.println("Circle area is\t:"+y);
}
void cal(int len)
{
x = len*len;
System.out.println("Squre area is\t:"+x);
}
void cal(int len,int br)
{
x = len*br;
System.out.println("Rectangle area is\t:"+x);
}
}
class area11
{
public static void main(String args[])throws IOException
{
DataInputStream in = new DataInputStream(System.in);
System.out.print("choose any one \t 1.CIRCLE \t 2.SQURE \t 3.RECTANGLE\t:");
try
{
int a = Integer.parseInt(in.readLine());
area A = new area();
if(a>=4 || a== 0)
throw new areae("Your Choice is Wrong");
if(a==1)
{
System.out.print("Enter the radius\t:");
int b = Integer.parseInt(in.readLine());
A.cal(3.14,b);
}
else if(a==2)
{
System.out.print("Enter the length\t:");
int c = Integer.parseInt(in.readLine());
if(c<=0)
throw new areae("Your length is worng");
A.cal(c);
}
else if(a==3)
{
System.out.print("Enter the length\t:");
int d = Integer.parseInt(in.readLine());
System.out.print("Enter the breath\t:");
int e = Integer.parseInt(in.readLine());
if(dthrow new areae("Your Breath is high");
A.cal(d,e);
}
}
catch (areae x)
{
System.out.println(x.getMessage());
}
}
}class Array
{
public static void main(String arg[])
{
try
{
//int arr[]=new int[]{10,20,30,50,60};
int arr[]={10,20,30,40};
/*arr=new int[5];
arr[0]=10;
arr[1]=20;
arr[2]=30;
arr[3]=40;
arr[4]=50;*/
for(int i =0 ;i<=arr.length;i++)
System.out.print(arr[i]+"\t");
}
catch(Exception e)
{
System.out.println("error is ="+e);
}
}
}import java.io.*;
class Array1
{
public static void main(String arg[])
{
try
{
InputStreamReader r = new InputStreamReader(System.in);
BufferedReader br= new BufferedReader(r);
int arr[];
arr=new int[5];
int total=0;
for(int j=0;j<=4;j++)
{

System.out.print("enter  no"+j +"=");
arr[j]= Integer.parseInt(br.readLine());
}
for(int i =0 ;i{
total=total+arr[i];
System.out.print(arr[i]+"\t");
}
int avg=total/5;
System.out.println("total     = "+total +"      avg="+avg);
}
catch(Exception e)
{
System.out.println("error is ="+e);
}
}
}import java.io.*;
import java.lang.*;
class arraye
{
public static void main(String args[])throws IOException
{
int a[] = new int [5];
int b;
DataInputStream in = new DataInputStream (System.in);
try
{
for(int i=0;i<5 i="" p="">{
System.out.print("choose the array location");
b = Integer.parseInt(in.readLine());
System.out.print("Enter the value");
a[b] = Integer.parseInt(in.readLine());
}
 a[3] /= (a[1]+a[0])/(a[2]-a[4]);
System.out.println("C is :"+a[3]);
}
catch(ArithmeticException x)
{
System.out.println(" IT CAN'T DIVISIBLE BY ZERO");
}
catch(ArrayIndexOutOfBoundsException x)
{
System.out.println(" IT IS EXCEEDED THE LIMIT");
}
catch(ArrayStoreException x)
{
System.out.println(" THE VALUE CAN BE ENTER WRONG FORMAT");
}
}
}/*

- Arrays is a container object that holds fixed no. of values of the same datatype.
- Length of an array is defined when the array is created and remains fixed.
- Each item in the array is called as an element.
- Each element can be accessed by its index number. The index number starts from '0'.

*/

public class arrays
{
public static void main(String[] args)
{
int[] anArray;
//Declares an array of 10 integers

anArray = new int[5];
//Allocates the variable anArray with 4 integers

anArray[0] = 100;
anArray[1] = 200;
anArray[3] = 400;
anArray[2] = 300;
anArray[4] = 500;
//Defines the value at each index of the array

for(int i=0; i<=4; i++)
{
System.out.println("Element at index " + i + " = " + anArray[i]);
}
}
}/*

- 2D arrays are arrays where each element of the array is itself an array
- Visualize it as a matrix or a determinant

*/

import java.io.*;

class arrays2D
{
public static void main(String[] args)
{
String[][] names = {{"Dr.", "Mr."},
{"Anish", "Vivek"},
{"Shrinivasan", "Menon"}};

System.out.println("All possible combinations");
for(int i=0; i<=2; i++)
{
for(int y=0; y<=1; y++)
{
System.out.println("Row: " + i + "Column: " + y + " = " + names[i][y]);
}
}
}
}class assertDemo
{
 void sqr(int num)
   {
   assert num>0:"-ve no. not allowed";
    int s=num*num;
     System.out.println("Sqr of "+num+"is" +s);
    }
   public static void main(String arg[])
    {
      assertDemo ad=new assertDemo();
       ad.sqr(10);
       ad.sqr(-8);
      }
 }class AssertTest
{
void sq(int n)
{
assert n>0:"Squiare is not allowed for (-)ve";
int s=n*n;
System.out.println("Square of"+n+" is "+s);
}
public static void main(String s[])
{
AssertTest a=new AssertTest();
a.sq(5);
a.sq(-2);
}
}import javax.swing.JOptionPane;

public class Average5Subjects
{
        public static void main(String[] args)
        {
    double Average;
    double sMath,sJava,sSociology,sHumanities,sPhysics;
    sMath=Double.parseDouble(JOptionPane.showInputDialog("Input Grade in Math "));
    sJava=Double.parseDouble(JOptionPane.showInputDialog("Input Grade in Java "));
    sSociology=Double.parseDouble(JOptionPane.showInputDialog("Input Grade in Operating System "));
    sHumanities=Double.parseDouble(JOptionPane.showInputDialog("Input Grade in Fil "));
    sPhysics=Double.parseDouble(JOptionPane.showInputDialog("Input Grade in Physics "));
    Average=((sMath + sJava + sSociology+sHumanities+sPhysics)/5);
    JOptionPane.showMessageDialog(null,"Average is " + Average);
    }
}
import java.io.*;

class bank
{
String name;
int accno;
String type;
int balance;

bank(int accno1,String name1,String type1)
{

accno = accno1;
name = name1;
type = type1;
}
void deposit(int accno1,int amt)
{
if(accno == accno1)
balance +=amt;
}
void withdraw(int accno1,int amt)
{
if(accno == accno1)
{
if(balance>=amt)
balance -=amt;
else
System.out.println("YOU CAN NOT WITH DRAW");
}
}
void display(int accno1)
{
if(accno == accno1)
System.out.println("Name  :"+name+"          balance       :"+balance) ;
}
}

class banka
{
public static void main(String args[])throws IOException
{
DataInputStream in = new DataInputStream(System.in);
int accno1,i;
String name1,type1;
bank [] B = new bank [10];
for(i=0;i<3 i="" p="">{
 accno1 = Integer.parseInt(in.readLine());
 name1 = in.readLine();
 type1 = in.readLine();
B[i] = new bank (accno1,name1,type1);
}
System.out.println("enter the acc no");
int an1 = Integer.parseInt(in.readLine());
int y=1;
do{
System.out.println("1.deposit    2.with draw    3.balance");
 int cho = Integer.parseInt(in.readLine());
System.out.println("enter the amount");
int amt1 = Integer.parseInt(in.readLine());

for( i=0;i<3 i="" p="">{
if (cho == 1)
{

B[i].deposit(an1,amt1);
}
else if (cho == 2)
{
B[i].withdraw(an1,amt1);
}
else
{
B[i].display(an1);
}

}
System.out.println("transaction   1");
y = Integer.parseInt(in.readLine());

}while (y==1);
}
}import java.io.*;
class Bank1Exception extends Exception
{
   int num=0;
     Bank1Exception()
      {
       System.out.println("Default of myexception"+num);
      }
      Bank1Exception(int n)
      {
        num=n;
        System.out.println("Entered amount is="+num);
       }
      public String toString()
      {
       return"Balance is not Enough"+num;
      }
 }
     class BankException
      {
 int bal=1000;
       void wid(int num)throws Bank1Exception
        {

            if(bal-num<500 p="">            {
              throw new Bank1Exception(num);
            }
            else
            {
             bal=bal-num;
             System.out.println("Balance  is "+bal);
            }
    }
        void dep(int num)
         {
 bal=bal+num;
  System.out.println("Balance  is "+bal);
        }
       int getbal()
        {
return(bal);
}
      public static void main(String arg[])
       {
        BankException ce=new BankException();
         try{
char aa='y';
 while(aa=='y' || aa=='Y')
{

InputStreamReader r=new InputStreamReader(System.in);
BufferedReader br=new BufferedReader(r);
System.out.println(" Enter 1 for Deposit\n Enter 2 for Witdraw \n Enter 3 for Balance Enqu ");
String str1=br.readLine();
int ch=Integer.parseInt(str1);
System.out.println("Enter Amount ");
String str2=br.readLine();
int num=Integer.parseInt(str2);
switch(ch)
 {
  case 1:
     ce.dep(num);
     break;
  case 2:
     ce.wid(num);
     break;
  case 3:
     int x=ce.getbal();
      System.out.println(" Amount is "+x);
      break;
  default:System.out.println("Enter  correct Choice ");
   }
   System.out.println("Want to Cont. enter y");
   aa=(char)br.read();

   }
           }catch(Bank1Exception me)
            {
             System.out.println("Caught inside main"+me);
             me.printStackTrace();
            }
           catch(Exception e)
            {
System.out.println("Error is "+e);
  }
           }

  }
import java.io.*;
class BankingDemo
{
int total_amount=500;
void deposit(int amount)
{
total_amount=total_amount+amount;
System.out.println("Total_amount is "+total_amount);
}
void withdrawn(int amount) throws BankingException
{
int am=total_amount-amount;
if(am<500 p=""> {
throw new BankingException(amount);
}
else
{
System.out.println(amount+" is withdrawn from "+total_amount);
total_amount=total_amount-amount;
}
}
int getbalance()
{
return total_amount;
}
public static void main(String s[]) throws BankingException
{
BankingDemo obj=new BankingDemo();
char c;
try
{
do
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("1. For Deposit\n2.For WithDrawn \n3. For Balance");
System.out.println("Enter Your Choice");
int ch=Integer.parseInt(br.readLine());
switch(ch)
{
case 1:
System.out.println("Enter the amount");
int amt=Integer.parseInt(br.readLine());
obj.deposit(amt);
break;
case 2:
System.out.println("Enter the to be WithDrawn");
int wh=Integer.parseInt(br.readLine());
obj.withdrawn(wh);
break;
case 3:
int balance=obj.getbalance();
System.out.println("Total amount balance is "+balance);
break;
default :
System.out.println("Your choice is wrong");
}
System.out.println("Do u want to continue(y/n)");
c=(char)br.read();
}while(c=='y' || c=='Y');
}catch(Exception e)
{
System.out.println("Invalid exception"+e);
}
}
}
class BankingException extends Exception
{
int n;
BankingException()
{
n=0;
System.out.println("Default constructor");
}
BankingException(int n)
{
this.n=n;
//System.out.println("Parametarize constructor");
}
public String toString()
{
return "U can't withdrawn"+n;
}
}class C1
{

public static void main(String args[])
{
System.out.println("main() in C1...");

}
}

class C2
{
public static void main(String args[])
{
System.out.println("main() in C2...");

}

}

/* Note: This code will compile successfully & generate C1.class & C2.class.
         But it won't execute. Runtime Error occurs. - ClassDefinitionNotFound.
         Class C1C2 not found
*/

// A simple command-line calculator


/* IMPORTANT: To perform multiplication, enclose * within a pair of
              double-quotes. e.g.

              java Calc "*" 4 5
*/


public class Calc
{

public static void main(String args[])
{


char op = args[0].charAt(0);
System.out.println("Operation : "+op);
int a = Integer.parseInt(args[1]);
int b = Integer.parseInt(args[2]);

switch(op)
{
case '+':
System.out.println(a+b);
break;

case '-':
System.out.println(a+b);
break;

case '*':
System.out.println(a*b);
break;
case '/':
System.out.println(a/b);
break;
default:
System.out.println("Invalid Choice");
}
}
}public class CharacterDemo {
    public static void main(String args[]) {
        Character a1 = new Character('a');
        Character a2 = new Character('a');
        Character b = new Character('b');

        int difference = a1.compareTo(b);

        if (difference == 0) {
            System.out.println("a1 is equal to b.");
        } else if (difference < 0) {
            System.out.println("a1 is less than b.");
        } else if (difference > 0) {
            System.out.println("a1 is greater than b.");
        }
        System.out.println("a1 is "
                           + ((a1.equals(a2)) ? "equal" : "not equal")
                           + " to a2.");
        System.out.println("The character " + a1.toString() + " is "
            + (Character.isUpperCase(a1.charValue()) ? "upper" : "lower")
            + "case.");
    }
}class CharFunc
{
public static void main(String args[])
{
char c1 = '9';
char c2 = '*';

if(Character.isDigit(c1)==true)
System.out.println("c1 a digit");
else
System.out.println("c1 is NOT a digit");

if(Character.isLetterOrDigit(c2)==true)
System.out.println("c2 is either a digit or letter");
else
System.out.println("c2 is neither a digit nor a letter");
}
}

/*

- Clock. The name says it all

*/

import java.io.*;
import java.util.*;

class clock
{
public static void main(String[] args)
{
Date d = new Date();
System.out.println("Date is " + d);


}
}class  Comparing{
public static void main(String[] args) {
int a=24, b=25;
if (a == b){
System.out.println("Both are equal");
}
else if(a>b){
System.out.println("a is greater than b");
}
else{
System.out.println("b is greater than a");
}
}
}
class ConstructTest
{
int x=2;
ConstructTest()
{
System.out.println("This is Default constructor");
}
ConstructTest(int x1)
{
x=x1;
System.out.println("This is Paraterized consturctor x="+x);
}
void  Square()
{
int s=x*x;
System.out.println("Sqaure of "+x+"is:"+s);
}
public static void main(String arg[])
{
ConstructTest t1=new ConstructTest();
ConstructTest t2=new ConstructTest(10);
t1.Square();
t2.Square();
}
}
public class Conversion
{

public static void main(String args[])
{

// int i =10.45F; ERROR-Possible loss of precision

int i = (int)10.45F; // OK - Explicit Casting

System.out.println(i);

i='A'; // OK - Implicit Casting

System.out.println(i);

// char ch = i; ERROR-Possible loss of precision

char ch = (char) i; // OK - Explicit Casting

System.out.println(ch);

ch++; // OR ch=66; Allowed

System.out.println(ch);

// ch=ch/11; ERROR-Possible loss of precision

float f = i; // OK

System.out.println(f);

f = ch; // OK

System.out.println(f);


byte b1=10,b2=20;

/* byte b3 = b1+b2;
  ERROR bcoz the arithemetic is carried out in integer mode only.
*/


}
}
class MyException extends Exception
{
   int num=0;
     MyException()
      {
       System.out.println("Default of myexception"+num);
      }
      MyException(int n)
      {
        num=n;
        System.out.println("Parametrized constructor of myexception"+num);
       }
      public String toString()
      {
       return"Sqr is not allowed for -ve no."+num;
      }
 }
     class CustomException
      {
       void Sqr(int num)throws MyException
       {
        if(num<0 p="">         {
          throw new MyException(num);
         }
        else
         {
          int s=num*num;
          System.out.println("Sqr of "+num+" is "+s);
         }
        }
      public static void main(String arg[])
       {
        CustomException ce=new CustomException();
         try{
           ce.Sqr(10);
           ce.Sqr(-9);
           }catch(MyException me)
            {
             System.out.println("Caught inside main"+me);
             me.printStackTrace();
            }
           }
  }
class DefaultHandling1
{
public static void main(String s[])
{
try
{
int a=10;
int b=0;
System.out.println("a="+a+"\n b="+b);
int c=a/b;
System.out.println("result is "+c);

}
catch(Exception e)
{
System.out.println("Error is "+e);
e.printStackTrace();
}
System.out.println("hello ");
}
} class DefHand
 {
    public static void main(String arg[])
     {
       try{
        int a=10,b=20;
        System.out.println("Value of a="+a+"and b="+b);
        int c=a/b;
        System.out.println("Result ="+c);
       }catch(Exception ae)
       {
         System.out.println("Error is"+ae);
        }finally
        {
         System.out.println("Hello");
      }
      }
     }
import java.net.*;
import java.io.*;
public class echo
{
     public static void main(String argv[])
     {
          Socket es=null;
          PrintStream os=null;
          DataInputStream is=null;
          DataInputStream stdin=new DataInputStream(System.in);

          try
          {
               es=new Socket("127.0.0.1",17);
               is=new DataInputStream(es.getInputStream());
               os=new PrintStream(es.getOutputStream());
             
          }
          catch (Exception e)
          {
               System.err.println(e);
           }

           if(es!=null && os!=null && is!=null)
           {
               try
               {
                    String userip;
                    while((userip=stdin.readLine())!=null)
                    {
                         os.println(userip);
                         String serverip =is.readLine();
                         System.out.println("echo: " + serverip);
                    }
                    os.close();
                    is.close();
                    es.close();
              }
              catch(Exception e)
              {
               System.err.println(e);
              }
         }
      }
 }