Category: BCA NOTES

Write a program to demonstrate Constructors and Destructors in VB.net.

WAP to Demonstrate Constructors and Destructors in VB.net.

 

Imports System.Console

Module Module1

Class base

Private a As Integer

Private b As Double

Private c As String

 

Public Sub New(ByVal x As Integer, ByVal y As Double, ByVal z As String)

WriteLine("Constructor Of Base Class Executed ! ")

a = x

b = y

c = z

WriteLine("a=" & a)

WriteLine("b=" & b)

WriteLine("c=" & c)

End Sub

 

Protected Overrides Sub finalize()

WriteLine("Destructor of Base Class Executed ! ")

End Sub

End Class

 

Class derive : Inherits base

Private d As Integer

Public Sub New(ByVal e As Integer, ByVal x As Integer, ByVal y As Double, ByVal z As String)

MyBase.New(x, y, z)

WriteLine("Constructor of Derived Class Executed!")

d = e

WriteLine("d=" & d)

End Sub

Protected Overrides Sub finalize()

WriteLine("Destructor of Derived Class Executed ! ")

End Sub

End Class

 

Sub Main()

WriteLine("When WE Declare Object of Base Classs :- ")

WriteLine()

WriteLine()

Dim s1 As base = New base(20, 30.5, "GOGO")

 

WriteLine("When WE Declare Object of Derived Classs :- ")

WriteLine()

WriteLine()

Dim s2 As derive = New derive(10, 20, 30.5, "GOGO")

 

End Sub

 

End Module

OUTPUT

Program to implement Constructors and Destructors in VB.net

output of vb.net Program to implement Constructors and Destructors

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admin October 17, 2014 0 Comments

Program in VB.Net to build a class which implements an interface

Que : Write a program in VB.Net to build a class which implements an interface

Ans:

Imports System.Console

 

Interface inf1

Sub show()

Sub disp()

End Interface

 

Class class1 : Implements inf1

 

Public Sub disp() Implements inf1.disp

WriteLine("Disp of class 1")

End Sub

 

Public Sub show() Implements inf1.show

WriteLine("show of Class 1")

End Sub

End Class

 

 

Module Module1

Sub Main()

Dim obj As class1 = New class1()

obj.disp()

obj.show()

 

End Sub

 

End Module

OUTPUT :

 

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admin October 17, 2014 0 Comments

Demonstrate Polymorphism in Vb.net through Constructor overloading.

Que : WAP to demonstrate Polymorphism in Vb.net through Constructor overloading.

 

Polymorphism in VB.NET

Polymorphism is the concept that different objects have different implementations of the same characteristic. … Given two different classes with the same properties and methods, a variable of type object could be used to instantiate an object of either class

 

Constructor overloading in vb.net

When the same method name is used for more than one method, with different types of parameters and returned types, then the method is said to be overloaded. Constructor is a special method called ‘New()’ in vb.net and is defined as a Sub.Overloading feature is used most frequently to overload the constructor. We overload the constructor by defining more than one ‘Sub New()’ procedure. By overloading a constructor, we make available more than one constructor.So, while creating an object we can choose which constructor we want to use to instantiate the object. The only condition while overloading the constructor is that the constructor should have a signature which is different from other constructors.

 

Imports System.Console

Module Module1

Structure areas

Public area As Integer

Public Sub display()

WriteLine("Area = " & area)

End Sub

Public Sub New(ByRef side As Integer)

area = side * side

End Sub

Public Sub New(ByVal l As Integer, ByVal b As Integer)

area = l * b

End Sub

Public Sub New(ByVal r As Double)

area = 4.13 * r * r

End Sub

End Structure

 

Sub Main()

Dim l, b, ch As Integer

Dim r As Double

WriteLine("1. Area of a Square")

WriteLine("2. Area of a Rectange")

WriteLine("3. Area of a Circle")

WriteLine("Enter Your Choice : ")

ch = ReadLine()

 

Select Case ch

Case 1

Write("Enter Size of a side : ")

l = ReadLine()

Dim s1 As areas = New areas(l)

s1.display()

Case 2

Write("Enter length : ")

l = ReadLine()

Write("Enter breadth : ")

b = ReadLine()

Dim s1 As areas = New areas(l, b)

s1.display()

Case 3

Write("Enter radius : ")

r = ReadLine()

Dim s1 As areas = New areas(r)

s1.display()

Case Else

WriteLine("Enter a Valid Choice")

End Select

End Sub

End Module

 

Output :

 

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admin October 17, 2014 0 Comments

WAP to demonstrate Polymorphism in Vb.net through Method Overloading

 Demonstratation of  Polymorphism in Vb.net through Method Overloading :

code begins :

(more…)

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admin October 17, 2014 0 Comments

Program to demonstrate abstract class and abstract methods in VB.net.

Ques :Write a program to demonstrate abstract class and abstract methods in VB.net. (more…)

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admin October 17, 2014 0 Comments

Java program on Deadlock

Before Checking Deadlock Program in java Lets Understand  the meaning of Deadlock in Java

What is Deadlock in Java?

 

Deadlock in java is a part of multi threading. Deadlock can occur in a situation when a thread is waiting for an object lock, that is acquired by another thread and second thread is waiting for an object lock that is acquired by first thread. Since, both threads are waiting for each other to release the lock, the condition is called deadlock.

 

Java Keywords that are synchronized are to make class thread-safe which means only one of the method has the lock of the synchronized method which can use it.

If the program that we are operating is running in a multi-threaded environment where two or more than two of the threads are working together. But this is not mandatory to work all the time this type of problem is called Deadlock in Java.

 

Java program on Deadlock

Here is Example of Java Program on Deadlock

class Resource
{ int sum;

synchronized void sumCalc ()
{
String tname = Thread.currentThread().getName() ;
System.out.println(tname + " is starting to calculate the sum ....." );
for(int i = 1 ; i<= 10 ; i++)
{
int x = (int ) (Math.random() *100 );
sum+=x ;
}
System.out.println("sum of " + tname + " : " +sum);
if(tname.equals ("first"))
{
System.out.println(tname + "is getting sum of the other thread .....");
int otherSum = Factory.r2.getSum() ;
int total = sum + otherSum ;
System.out.println("total sum in "+ tname + " = "+total );
}
if(tname . equals ("second"))
{
System.out.println(tname + "is getting sum of the other thread .....");
int otherSum = Factory.r1.getSum() ;
int total = sum + otherSum ;
System.out.println("total sum in "+ tname + " = "+total );
}
}

synchronized int getSum()
{
return (sum );
}

}

class Factory
{
static Resource r1,r2 ;
static {r1 = new Resource();
r2 = new Resource() ;
}
}
class MyThread extends Thread
{
MyThread (String name )
{
super (name );
start() ;

}
public void run ()
{
String tname = getName () ;
if(tname.equals ("first"))
{
Factory.r1.sumCalc() ;

}
if(tname.equals ("second"))
{
Factory.r2.sumCalc() ;

}

}
}

class DeadlockTest
{
public static void main(String s[] )
{
new MyThread ("first");
new MyThread ("second");
}
}

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admin March 17, 2014 0 Comments

Java program for event Handelling

Java program for event Handelling

import java.awt.*;
import java.awt.event.*;
class EventTest implements ActionListener
{Frame fr;
Button b1,b2,b3,b4;
TextField tf1,tf2,tf3;
Label lb1,lb2,lb3;

EventTest( )
{ fr = new Frame("myframe" );
fr.setLayout(null);
b1= new Button ("Add") ;
b2= new Button ("Sub") ;
b3= new Button ("Mul") ;
b4= new Button ("Div") ;
tf1 = new TextField() ;
tf2 = new TextField() ;
tf3= new TextField() ;
lb1 = new Label("no1") ;
lb2 = new Label("no2") ;
lb3 = new Label("res") ;
tf1.setBounds( 50,50,100,50) ;
tf2.setBounds( 50,120,100,50) ;
tf3.setBounds( 50,190,100,50) ;
lb1.setBounds(10,50,35,50);
lb2.setBounds(10,120,35,50);
lb3.setBounds(10,190,35,50);
b1.setBounds( 30,260,35,50);
b2.setBounds( 85,260,35,50);
b3.setBounds( 140,260,35,50);
b4.setBounds( 195,260,35,50);
fr.add( tf1) ;
fr.add( tf2) ;
fr.add( tf3) ;
fr.add( lb1) ;
fr.add( lb2) ;
fr.add( lb3) ;
fr.add( b1) ;
fr.add( b2) ;
fr.add( b3) ;
fr.add( b4) ;
b1.addActionListener( this );
b2.addActionListener( this );
b3.addActionListener( this );
b4.addActionListener( this );

fr.setSize(600,700);
fr.setVisible(true);
}
public void actionPerformed (ActionEvent e )
{
if ( e.getSource() == b1 )
{
String str1 = tf1.getText() ;
String str2 = tf2.getText() ;
int s1 = Integer.parseInt(str1) ;
int s2 = Integer.parseInt(str2) ;
int result = (s1+s2) ;
String str3 =" " + result ;
tf3.setText ( str3) ;
}

if ( e.getSource() == b2 )
{
String str1 = tf1.getText() ;
String str2 = tf2.getText() ;
int s1 = Integer.parseInt(str1) ;
int s2 = Integer.parseInt(str2) ;
int result = s1-s2 ;
String str3 =" " + result ;
tf3.setText ( str3) ;
}
if ( e.getSource() == b3 )
{
String str1 = tf1.getText() ;
String str2 = tf2.getText() ;
int s1 = Integer.parseInt(str1) ;
int s2 = Integer.parseInt(str2) ;
int result = s1*s2 ;
String str3 =" " + result ;
tf3.setText ( str3) ;
}

if ( e.getSource() == b4 )
{
String str1 = tf1.getText() ;
String str2 = tf2.getText() ;
int s1 = Integer.parseInt(str1) ;
int s2 = Integer.parseInt(str2) ;
int result = (s1/s2) ;
String str3 =" " + result ;
tf3.setText ( str3) ;
}
}

public static void main (String s[] )
{
new EventTest();
}

}

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admin March 17, 2014 0 Comments

Java Program for working Pacman game

Java Program/source code for working Pacman Game. This program is primarily based on the game pacman….. A running pacman eating piece according to light signals red ,green or yellow just run this java program to see live working pacman game ,
It consist of three (2 java files + 1 html file ) files :
1)PackManAndRedLight.java
2)RedLight.java
3)redlight+packman.html

Steps to run Java Program/source code for working Pacman Game :

Copy the code and save three files in same folder with names as mentioned above

compile two files at a time via running this command on cmd :

javac *.java

after that open redlight+packman.html in your browser

Done 🙂

so here is the source code for running pacman game

import java.awt.Color;
import java.awt.Graphics;
import java.applet.Applet;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import javax.swing.JApplet;
import java.applet.AppletContext;

class mythread1 extends Thread
{
PackManAndRedLight pack;
char dir;
mythread1(PackManAndRedLight pack)
{
this.pack=pack;
pack.x=0;
pack.y=0;
pack.ang=315;
pack.stang=23;
dir='r';
start();
}
public void run()
{
try
{
for(;pack.y<=550;)
{
if(pack.rd.clr=='g')
{
pack.repaint();
if(dir=='r')
{
pack.x+=5;
pack.recy=pack.y;
pack.recx=pack.x-25;
pack.repaint();
if(pack.x>760)
{
pack.recx=740;
pack.repaint();
pack.showStatus(""+pack.rd.clr);
dir='d';
}
if(pack.x%50==45)
{
pack.ang=360;
pack.stang=270;
}
else
{
pack.stang=23;
pack.ang=315;
}
}
if((dir=='d'))
{
pack.recx=pack.x;
pack.recy=pack.y-25;
pack.y+=5;
if(pack.y%50==0)
{
if(pack.x>50)
{
pack.repaint();
pack.showStatus(""+pack.rd.clr);
dir='l';
}
else
dir='r';
}
if(pack.y%50==30)
{
pack.ang=360;
pack.stang=270;
}
else
{
pack.stang=293;
pack.ang=315;
}
}
if(dir=='l')
{
pack.recy=pack.y;
pack.recx=pack.x+25;
//pack.stang=203;
pack.x-=5;
if(pack.x<20)
dir='d';
if(pack.x%50==30)
{
pack.ang=360;
pack.stang=0;
}
else
{
pack.ang=315;
pack.stang=203;
}
}
Thread.sleep(50);
}
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
public class PackManAndRedLight extends JApplet implements MouseMotionListener
{
int x,y,stang,ang;
int recx,recy;
boolean flag;
mythread1 mth;
String str="";
RedLight rd;
@Override
public void init()
{
flag=false;
x=0;
y=0;
stang=23;
ang=315;
addMouseMotionListener(this);
AppletContext ct=getAppletContext();
rd=(RedLight)ct.getApplet("redlight");
System.out.println(""+rd);
}
public void start()
{
flag=false;
mth=new mythread1(this);
}
@Override
public void mouseDragged(MouseEvent e)
{

}
@Override
public void mouseMoved(MouseEvent e)
{
str=(" x = "+e.getX()+" y = "+e.getY());
}
@Override
public void paint(Graphics g)
{
if(flag==false)
{
flag=true;
int x1=75,y1=25;
for(;y1<600;)
{
g.setColor(Color.red);
g.fillOval(x1+10, y1-5, 10, 10);
if(x1>750)
{
x1=-25;
y1+=50;
}
x1+=50;
}
}
g.setColor(Color.white);
g.fillRect(recx, recy, 50,50);
g.setColor(Color.yellow);
g.fillArc(x, y, 50,50, stang, ang);showStatus(str+rd.clr);
}
}

RedLight.java

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
class red_thread extends Thread
{
 char lclr;
 RedLight rl;
 red_thread(RedLight rl)
 {
 this.rl=rl;
 start();
 }
 @Override
 public void run()
 { 
 while(true)
 {
 try
 {
 if(rl.clr=='r')
 {
 Thread.sleep(10000);
 lclr='r';
 rl.clr='y'; 
 }
 else if(rl.clr=='g')
 {
 Thread.sleep(10000);
 lclr='g';
 rl.clr='y';
 }
 else if(rl.clr=='y')
 {
 Thread.sleep(3000);
 if(lclr=='r')
 rl.clr='g';
 else
 rl.clr='r';
 }
 rl.repaint();
 }
 catch(Exception e)
 {
 e.printStackTrace();
 }
 }
 } 
}
public class RedLight extends Applet 
{
 int clr='r';
 public void init() 
 { 
 new red_thread(this); 
 }
 @Override
 public void paint(Graphics g)
 {
 g.fillRect(40,40,120,360);
 g.setColor(Color.DARK_GRAY);
 g.fillOval(50,50,100,100);
 g.fillOval(50,170,100,100);
 g.fillOval(50,290,100,100);
 if(clr=='r')
 {
 g.setColor(Color.red);
 g.fillOval(50,50,100,100);
 }
 else if(clr=='y')
 {
 g.setColor(Color.orange);
 g.fillOval(50,170,100,100);
 }
 else
 {
 g.setColor(Color.green);
 g.fillOval(50,290,100,100);
 } 
 }
}

redlight+packman.html


Output Screenshots of working Pacman game

Java Program for working Pacman Redlight2. 3.

java Program/source code for working PacmanSo, this was all for now about the JAVA Program for working Pacman Game. To know more about programming and more such stuff, check out https://www.worldtopupdates.com/.

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admin February 18, 2014 0 Comments