jalab record

7/29/2019 Jalab Record

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Ex No1: Rational Numbers

AIM To write a Java Program to develop a class for Rational numbers.

ALGORITHM:

Step 1:-Declare a class called Rational and invoke a function called gcd(a,b).

Step 2:-Find out the reminder when a is divided by b and pass it as a parameter to thefunction.

Step 3:-Create an object for the class and declare the required string and integervariables.

Step 4:-Create an object of class DataInputStream .Read the numbers through theReadLine() method into the object.

Step 5:-Convert the input accepted into Integers through the parseInt method and storethem in variables a and b.

Step 6:-store the value returned by the function GCD in variable l.

Step 7:-Divide a by l and b by l and store them in variables x and y.


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Program:-

import java.io.*;class rational1{

public rational1(){}

public long gcd(long a,long b){

if(b==0)return a;elsereturn gcd(b,a%b);

}}public class rational{

public static void main(String args[])throws IOException{

rational1 r=new rational1();

long a,b,x,y;String str;DataInputStream in= new DataInputStream(System.in);System.out.println("Enter the value for A");str=in.readLine();a=Integer.parseInt(str);System.out.println("Enter the value for B");str=in.readLine();b=Integer.parseInt(str);

long l=r.gcd(a,b);System.out.println();System.out.println("The GCD of the number is:"+l);x=a/l;y=b/l;System.out.println();System.out.println("The resultant value is: "+x+"/"+y);

}}


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Output

Enter the value for A500Enter the value for B1000

The GCD of the number is:500

The resultant value is: 1/2Ex No 2: Date Class in Java

AIM

To design a Date class in Java .

ALGORITHM:-

Step 1:Declare a class called Dateexample and create an object called date.

Step 2:-Display the Date and Time through these objects with theMethods in Date Class.

Step 3:-Declare two objects called starttime and endtime for this class .

Step 4:-Create another object called changed object and display the changed time withthe calculation 24L*60L*60L*1000L.

Step 5:-In the main function create object for the class Date and display the time and dateaccordingly.


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SOURCE CODE

import java.util.Date;import java.text.ParseException;import java.text.SimpleDateFormat;public class DateExample {

private static void DateExample() {

Date date = new Date();System.out.println("Current Date and Time is : " + date);System.out.println();

System.out.println("Date object showing specific date and time");Date particulardate1 = new Date(24L*60L*60L*1000L);Date particulardate2 = new Date(0L);System.out.println();System.out.println("First Particular date : " + particulardate1);System.out.println("Second Particular date: " + particulardate2);System.out.println();

System.out.println("Demo of getTime() method returning milliseconds");System.out.println();Date strtime = new Date();System.out.println("Start Time: " + strtime);Date endtime = new Date();System.out.println("End Time is: " + endtime);


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long elapsed_time = endtime.getTime() - strtime.getTime();System.out.println("Elapsed Time is:" + elapsed_time + " milliseconds");System.out.println();

System.out.println("Changed date object using setTime() method");

System.out.println();Date chngdate = new Date();System.out.println("Date before change is: " + chngdate);chngdate.setTime(24L*60L*60L*1000L);System.out.println("Now the Changed date is: " + chngdate);System.out.println();

}

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

}

}

OUTPUT

Current Date and Time is : Mon Dec 10 18:39:27 GMT+05:30 2007

Date object showing specific date and time

First Particular date : Fri Jan 02 05:30:00 GMT+05:30 1970Second Particular date: Thu Jan 01 05:30:00 GMT+05:30 1970

Demo of getTime() method returning milliseconds

Start Time: Mon Dec 10 18:39:28 GMT+05:30 2007End Time is: Mon Dec 10 18:39:28 GMT+05:30 2007Elapsed Time is:0 milliseconds

Changed date object using setTime() method

Date before change is: Mon Dec 10 18:39:28 GMT+05:30 2007Now the Changed date is: Fri Jan 02 05:30:00 GMT+05:30 1970


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Ex4 : Implementation of Stack ADT

AIM

To write a Java Program to design an interface for Stack ADT.and implementStack ADT using both Array and Linked List.

ALGORITHM

Step 1:Declare an array for storing the stack elements and initialise the capacity of thearray.

Step 2:-Declare functions makeempty(),isempty() to check whether the stack is empty toinsert an element.

Step 3:After inserting an element,increment the counter by 1 to increase the number ofelements in stack.

Step 4:Initiate another array to extend the size of the array when the number of elementsexceed beyond the limit.

Step 5:-Invoke methods and constructors to implement the stack using linked list.


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Step 6:-Test if the stack is logically empty.then return true or else false.

Step 7:To delete an element from stack,check if stack is empty,if so throw an exceptionor else move to the next element in the stack.

Step 8:To return the most recently inserted element use the method topOfStack() andthen move the pointer to the next element.

Step 9:Declare a stack Interface to push and pop elements from stack.

Step 10:create two objects one for array and other for linked list implementation of stack.

Step 11:Insert characters and numbers into the stack using the methods and display theinserted elements with exception blocks.

SOURCE CODE

/*** Array-based implementation of the stack.*/public class ArrayStack implements Stack {

private Object [ ] theArray;private int topOfStack;private static final int DEFAULT_CAPACITY = 10;

/*** Construct the stack.*/public ArrayStack( ) {

theArray = new Object[ DEFAULT_CAPACITY ];topOfStack = -1;

}

/*** Test if the stack is logically empty.* @return true if empty, false otherwise.*/public boolean isEmpty( ) {

return topOfStack == -1;


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}

/*** Make the stack logically empty.*/

public void makeEmpty( ) {topOfStack = -1;}

/*** Get the most recently inserted item in the stack.* Does not alter the stack.* @return the most recently inserted item in the stack.* @throws UnderflowException if the stack is empty.*/public Object top( ) {

if( isEmpty( ) )throw new UnderflowException( "ArrayStack top" );return theArray[ topOfStack ];

}

/*** Remove the most recently inserted item from the stack.* @throws UnderflowException if the stack is empty.*/public void pop( ) {

if( isEmpty( ) )

throw new UnderflowException( "ArrayStack pop" );topOfStack--;}

/*** Return and remove the most recently inserted item* from the stack.* @return the most recently inserted item in the stack.* @throws Underflow if the stack is empty.*/public Object topAndPop( ) {

if( isEmpty( ) )throw new UnderflowException( "ArrayStack topAndPop" );return theArray[ topOfStack-- ];

}

/*** Insert a new item into the stack.* @param x the item to insert.


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*/public void push( Object x ) {

if( topOfStack + 1 == theArray.length )doubleArray( );

theArray[ ++topOfStack ] = x;

}/*** Internal method to extend theArray.*/private void doubleArray( ) {

Object [ ] newArray;

newArray = new Object[ theArray.length * 2 ];for( int i = 0; i < theArray.length; i++ )

newArray[ i ] = theArray[ i ];

theArray = newArray;}

}

//ListStack class//// CONSTRUCTION: with no initializer//// ******************PUBLIC OPERATIONS*********************// void push( x ) --> Insert x// void pop( ) --> Remove most recently inserted item// Object top( ) --> Return most recently inserted item// Object topAndPop( ) --> Return and remove most recent item// boolean isEmpty( ) --> Return true if empty; else false


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// void makeEmpty( ) --> Remove all items// ******************ERRORS********************************// top, pop, or topAndPop on empty stack

/**

* List-based implementation of the stack.*/public class LinkedListStack implements Stack {

/*** Construct the stack.*/

public LinkedListStack( ) {topOfStack = null;

}

/**

* Test if the stack is logically empty.* @return true if empty, false otherwise.*/

public boolean isEmpty( ) {return topOfStack == null;

}


public void makeEmpty( ) {

topOfStack = null;}

/*** Insert a new item into the stack.* @param x the item to insert.*/

public void push( Object x ) {topOfStack = new ListNode( x, topOfStack );

}

/*** Remove the most recently inserted item from the stack.* @throws UnderflowException if the stack is empty.*/

public void pop( ) {if( isEmpty( ) )

throw new UnderflowException( "ListStack pop" );topOfStack = topOfStack.next;


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}

/*** Get the most recently inserted item in the stack.* Does not alter the stack.

* @return the most recently inserted item in the stack.* @throws UnderflowException if the stack is empty.*/

public Object top( ) {if( isEmpty( ) )

throw new UnderflowException( "ListStack top" );return topOfStack.element;

}

/*** Return and remove the most recently inserted item

* from the stack.* @return the most recently inserted item in the stack.* @throws UnderflowException if the stack is empty.*/

public Object topAndPop( ) {if( isEmpty( ) )

throw new UnderflowException( "ListStack topAndPop" );

Object topItem = topOfStack.element;topOfStack = topOfStack.next;return topItem;

}

private ListNode topOfStack;

}

public class ListNode {public Object element;public ListNode next;

// Constructorspublic ListNode( Object theElement ) {

this( theElement, null );}


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public ListNode( Object theElement, ListNode n ) {element = theElement;next = n;

}}

public interface Stack {/*** Insert a new item into the stack.* @param x the item to insert.*/void push( Object x );

/*** Remove the most recently inserted item from the stack.

* @exception UnderflowException if the stack is empty.*/void pop( );

/*** Get the most recently inserted item in the stack.* Does not alter the stack.* @return the most recently inserted item in the stack.* @exception UnderflowException if the stack is empty.*/Object top( );

/*** Return and remove the most recently inserted item* from the stack.* @return the most recently inserted item in the stack.* @exception UnderflowException if the stack is empty.*/Object topAndPop( );

/*** Test if the stack is logically empty.* @return true if empty, false otherwise.*/

boolean isEmpty( );



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void makeEmpty( );

}

public class StackTester {

public static void main(String[] args) {

System.out.println("******************************************");System.out.println("Stack using Array & Linked List example");

System.out.println("******************************************");

ArrayStack arrayStack = new ArrayStack();arrayStack.push(new String("a"));arrayStack.push(new String("b"));arrayStack.push(new String("c"));System.out.println("Stack[using array] elements -> a, b, c");System.out.println("Stack LIFO and POP -> "+arrayStack.topAndPop());System.out.println("Stack LIFO -> "+arrayStack.top());arrayStack.pop();try{

arrayStack.pop();arrayStack.topAndPop();}catch(RuntimeException rte){

System.err.println("Exception occured while POP operation ishappened on Stack[by using array]");

}System.out.println("\n\n******************************");System.out.println("Stack using Linked List example");System.out.println("******************************");

LinkedListStack linkedListStack = new LinkedListStack();linkedListStack.push(new Integer(10));linkedListStack.push(new Integer(20));linkedListStack.push(new Integer(30));linkedListStack.push(new Integer(40));System.out.println("Stack[using linked list] elements -> 10, 20, 30, 40");System.out.println("Stack TOP ->"+linkedListStack.top());linkedListStack.pop();System.out.println("Stack TOP after POP ->"+linkedListStack.top());


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linkedListStack.pop();linkedListStack.pop();linkedListStack.pop();try{

linkedListStack.pop();

}catch(RuntimeException rte){System.err.println("Exception occured while POP operation ishappened on Stack[by using linked list]");

}

}}

/**

* Exception class for access in empty containers* such as stacks, queues, and priority queues.* @author Ramkumar*/

public class UnderflowException extends RuntimeException {/*** Construct this exception object.* @param message the error message.*/

public UnderflowException( String message ) {super( message );

}}

OUTPUT

Stack using Array & Linked List example

******************************************

Stack[using array] elements -> a, b, c

Stack LIFO and POP -> c

Stack LIFO -> b

Exception occured while POP operation is happened on Stack[by using array]

******************************


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Stack using Linked List example

******************************

Stack[using linked list] elements -> 10, 20, 30, 40

Stack TOP ->40

Stack TOP after POP ->30

Exception occured while POP operation is happened on Stack[by using linked list]

Ex no:5 Polymorphism

Aim:- To develop a vehicle class hierarchy in Java to demonstrate the concept ofpolymorphism.

Algorithm:-

Step 1:-Declare a super class called vehicle with data elements doors,wheels and seats.

Step 2:-Derive another class called car and invoke a function tostring() to display thevariables.

Step 3:-Derive another class called motorcycle with same data and method calledsetseats() .

Step 4:-Declare another sub class called Truck with 2 constructors and finally assignvalues to variables.

Step 5:-In the main function, create an object for class motorcycle and display all detailsof sub classes through object.

Sourcecode:-


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//This is the class that will be inheritedpublic class Vehicle{

public int doors;public int seats;

public int wheels;Vehicle(){

wheels=4;doors=4;

seats=4;}

}//This class inherits Vehicle.javapublic class Car extends Vehicle{

public String toString(){return "This car has "+seats+" Seats, "+doors+" Doors "+

"and "+wheels+" wheels.";}

}//This class inherits Vehicle.javapublic class MotorCycle extends Vehicle{

MotorCycle(){

wheels=2;doors=0;seats=1;

}void setSeats(int num){

seats=num;}public String toString(){

return "This motorcycle has "+seats+" Seats, "+doors+" Doors "+"and "+wheels+" wheels.";

}}//This class inherits Vehicle.javapublic class Truck extends Vehicle{

boolean isPickup;Truck()


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{isPickup=true;

}Truck(boolean aPickup){

this();isPickup=aPickup;}Truck(int doors, int seats, int inWheels, boolean isPickup){

this.doors=doors;this.seats=seats;wheels=inWheels;this.isPickup=isPickup;

}public String toString()

{ return "This "+(isPickup?"pickup":"truck")+" has "+seats+" Seats, "+doors+" Doors "+"and "+wheels+" wheels.";

}}//This class tests the classes that inherit Vehicle.javapublic class VehiclesTest{

public static void main(String args[]){

MotorCycle mine = new MotorCycle();

System.out.println(mine);Car mine2 = new Car();System.out.println(mine2);mine2.doors=2;System.out.println(mine2);Truck mine3 = new Truck();System.out.println(mine3);Truck mine4 = new Truck(false);mine4.doors=2;System.out.println(mine4);

}}

Output

This motorcycle has 1 Seats, 0 Doors and 2 wheelsThis car has 4 Seats, 4 Doors and 4 wheels


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This car has 4 Seats, 2 Doors and 4 wheelsThis pickup has 4 Seats, 4 Doors and 4 wheelsThis truck has 4 Seats, 2 Doors and 4 wheels

Ex No:-6 Object Serialization

Aim:-To write a Java Program to randomly generate objects and write them into a fileusing concept of Object Serialization.

Algorithm:-

Step 1:Declare a class called Currency .Open a file in output mode with a name.

Step 2:-Write new data into the object using writeobject() method.

Step 3:-Similarly create an input stream object .Read it both in terms of Dollars andRupees.close the output object.

Step 4:-derive a class called Dollar which implements serializable interface.Invoke aconstructor and function to display the data.

Step 5:Similarly declare a class called Rupee with private variables and use print functionto display the variables.

Step 6:terminate the execution.The output is displayed as dollar to rupee conversion andvice versa.

Sourcecode:-

// Currency conversionimport java.io.*;public class Currency{

public static void main(String args[]){

Dollar dr=new Dollar('$',40);dr.printDollar();Rupee re=new Rupee("Rs.",50);


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re.printRupee();try{File f=new File("rd.txt");FileOutputStream fos=new FileOutputStream(f);

ObjectOutputStream oos=new ObjectOutputStream(fos);oos.writeObject(dr);oos.writeObject(re);oos.flush();oos.close();ObjectInputStream ois=new ObjectInputStream(new FileInputStream("rd.txt"));Dollar d1;d1=(Dollar)ois.readObject();d1.printDollar();Rupee r1;r1=(Rupee)ois.readObject();

r1.printRupee();ois.close();}catch(Exception e){}

}}class Dollar implements Serializable{

private float dol;private char sym;

public Dollar(char sm,float doll){

sym=sm;dol=doll;

}void printDollar(){

System.out.print(sym);System.out.println(dol);

}}class Rupee implements Serializable{

private String sym;private float rs;public Rupee(String sm,float rup)


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{sym=sm;rs=rup;

}void printRupee()

{ System.out.print(sym);System.out.println(rs);

}

}

Output:-

E:\java>java Currency$40.0Rs.50.0$40.0Rs.50.0

Ex No:7 Event-Driven Programming

AIM

To develop a scientific calculator using even-driven programming paradigm ofJava.

ALGORITHM:


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Step 1:-Import all the packages required for designing the graphical elements in theapplet window.

Step 2:-Implement the Listener files for Keyboard, mouse events in the class defined.

Step 3:-Import the swing package in the program for using swing components for thrgridLayout design for menu,Frame,Dialog ,TextArea,Label and other components foralignment in the applet window.

Step 4:-Create objects from the main classes for JLabel,Jtextbox,JPanel ,Font and Menu items.

Step 5:Assign the font items to all the menu items and add them to the panel.

Step 6:-Create the GridBagLayout and add all the buttons to it using the swing class.

Step 7:-Add all the JButtons to the panel and also the colour components to the GUI controls.

Step 8:-Call adddighitstodisplay() to activate the required arithmetic operations when the buttonsare pressed.

Step 9:Invoke the function displayresult() to store the result of the values computed.

Step 10:-Handle the divide by zero exception outside the class definition. And create an objectfor the class created.

Step 11:-Add all the methods,properties and layout to the panel window and display the result inthe textarea created.

Step 12:-Invoke the actionPerformed() method through the ActionEvent class and write code foreach operator or number being pressed.

SOURCE CODE:=-

import java.awt.BorderLayout;import java.awt.Color;import java.awt.Container;import java.awt.FlowLayout;import java.awt.Font;import java.awt.GridLayout;import java.awt.Window;import java.awt.event.ActionEvent;


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import java.awt.event.ActionListener;import java.awt.event.KeyEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;

import javax.swing.JButton;import javax.swing.JDialog;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JMenuItem;import javax.swing.JPanel;import javax.swing.JTextArea;import javax.swing.KeyStroke;

public class Calculator extends JFrame implements ActionListener {

// Variables

final int MAX_INPUT_LENGTH = 20;final int INPUT_MODE = 0;final int RESULT_MODE = 1;final int ERROR_MODE = 2;int displayMode;

boolean clearOnNextDigit, percent;double lastNumber;String lastOperator;

private JMenu jmenuFile, jmenuHelp;private JMenuItem jmenuitemExit, jmenuitemAbout;

private JLabel jlbOutput;private JButton jbnButtons[];

private JPanel jplMaster, jplBackSpace, jplControl;

/** Font(String name, int style, int size)

Creates a new Font from the specified name, style and point size.*/

Font f12 = new Font("Times New Roman", 0, 12);Font f121 = new Font("Times New Roman", 1, 12);


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// Constructorpublic Calculator(){

/* Set Up the JMenuBar.* Have Provided All JMenu's with Mnemonics

* Have Provided some JMenuItem components with KeyboardAccelerators*/

jmenuFile = new JMenu("File");jmenuFile.setFont(f121);jmenuFile.setMnemonic(KeyEvent.VK_F);

jmenuitemExit = new JMenuItem("Exit");jmenuitemExit.setFont(f12);

jmenuitemExit.setAccelerator(KeyStroke.getKeyStroke( KeyEvent.VK_X,

ActionEvent.CTRL_MASK));jmenuFile.add(jmenuitemExit);

jmenuHelp = new JMenu("Help");jmenuHelp.setFont(f121);jmenuHelp.setMnemonic(KeyEvent.VK_H);

jmenuitemAbout = new JMenuItem("About Calculator");jmenuitemAbout.setFont(f12);

jmenuHelp.add(jmenuitemAbout);

JMenuBar mb = new JMenuBar();mb.add(jmenuFile);mb.add(jmenuHelp);setJMenuBar(mb);

//Set frame layout manager

setBackground(Color.gray);

jplMaster = new JPanel();

jlbOutput = new JLabel("0");jlbOutput.setHorizontalTextPosition(JLabel.RIGHT);jlbOutput.setBackground(Color.WHITE);jlbOutput.setOpaque(true);

// Add components to frame


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getContentPane().add(jlbOutput, BorderLayout.NORTH);

jbnButtons = new JButton[23];// GridLayout(int rows, int cols, int hgap, int vgap)

JPanel jplButtons = new JPanel(); // container for Jbuttons

// Create numeric Jbuttonsfor (int i=0; i


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jbnButtons[i].setForeground(Color.blue);

elsejbnButtons[i].setForeground(Color.red);

}

// Set panel layout manager for a 4 by 5 gridjplButtons.setLayout(new GridLayout(4, 5, 2, 2));

//Add buttons to keypad panel starting at top left// First rowfor(int i=7; i


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jplMaster.setLayout(new BorderLayout());jplMaster.add(jplBackSpace, BorderLayout.WEST);jplMaster.add(jplControl, BorderLayout.EAST);jplMaster.add(jplButtons, BorderLayout.SOUTH);

// Add components to framegetContentPane().add(jplMaster, BorderLayout.SOUTH);requestFocus();

//activate ActionListenerfor (int i=0; i


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{if(e.getSource() == jbnButtons[i]){

switch(i){

case 0: addDigitToDisplay(i);break;

case 1:addDigitToDisplay(i);break;




case 5:addDigitToDisplay(i);

break;





case 10: // +/-


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processSignChange();break;

case 11: // decimal pointaddDecimalPoint();

break;

case 12: // =processEquals();break;

case 13: // divideprocessOperator("/");break;

case 14: // *

processOperator("*");break;

case 15: // -processOperator("-");break;

case 16: // +processOperator("+");break;

case 17: // sqrtif (displayMode != ERROR_MODE){

try{

if(getDisplayString().indexOf("-") == 0)

displayError("Invalid inputfor function!");

result = Math.sqrt(getNumberInDisplay());displayResult(result);

}

catch(Exception ex){

displayError("Invalid input for function!);displayMode = ERROR_MODE;

}


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}break;

case 18: // 1/xif (displayMode != ERROR_MODE){

try{if (getNumberInDisplay() ==

0)displayError("Cannot

divide by zero!");

result = 1 /getNumberInDisplay();

displayResult(result);}

catch(Exception ex) {displayError("Cannot divide

by zero!");displayMode =

ERROR_MODE;}

}break;

case 19: // %

if (displayMode != ERROR_MODE){try {result =

getNumberInDisplay() / 100;displayResult(result);

}

catch(Exception ex) {displayError("Invalid input

for function!");displayMode =

ERROR_MODE;}

}break;

case 20: // backspaceif (displayMode != ERROR_MODE){


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setDisplayString(getDisplayString().substring(0,

getDisplayString().length() - 1));

if (getDisplayString().length() < 1)setDisplayString("0");}break;

case 21: // CEclearExisting();break;

case 22: // CclearAll();

break;}}

}}

void setDisplayString(String s){jlbOutput.setText(s);

}

String getDisplayString (){

return jlbOutput.getText();}

void addDigitToDisplay(int digit){if (clearOnNextDigit)

setDisplayString("");

String inputString = getDisplayString();

if (inputString.indexOf("0") == 0){inputString = inputString.substring(1);

}

if ((!inputString.equals("0") || digit > 0)&& inputString.length()

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