A COMPLETE GUIDE OF COMPUTER NOTES

Java program to calculate rectangle area using Scanner classes: import java.util.Scanner; public class Rarea { public static void main(String[] args) { Scanner inn = new Scanner(System.in); double height, width, area; System.out.println(“Area of Rectangle”); System.out.print(“Please enter the height: “); height = inn.nextDouble(); System.out.print(“Please enter the width: “); width = inn.nextDouble(); area = height * width; System.out.println(“Area: […]

The Event classes represent the events that are generated when an end user interacts with the AWT components. the EventObject class is the superclass for handling all events. the class exists in the package, java. util. The AWTEvent class is the subclass of the EventObject class and all AWT events originate from the AWTEvent class. […]

To display text(write the text), you must first select a font. A font is specified by its names, such as “Arial”,  the style(plain, bold, italic, or bold italics), and the point size. A font is an object in Java, so we need to create it via a call to new before we can use it. […]

The switch statement is a multi-way decision-making statement in which we can select only one . The switch statement starts with the “switch” keyword like (switch(expression)). Switch defines one or more case values which we know as case labels. Case labels consist of case keywords followed by a colon(:), and every case is terminated by […]

Daemon Thread There are two types of threads The threads created by the user(create a thread in the program ) are called user threads. The threads that work in the background providing service to others are called Daemon Threads. The two methods used only  in the daemon thread, not in the user thread are: Example […]

Finally blocks(finally{}) are executed once the try block(try{}) exits. This block executes even after unexpected exceptions(errors) have occurred. Irrespective of the try block, the expression in finally block(finally{})  is always executed. This block(finally{}) is in-built with the capability of recovering lost and preventing the leak of resources. On closing and recovery of a file, the […]

Borders are basically margined around the edges of a Swing component. Borders are useful for providing titles and empty spaces around components. The setBorder() is used to put a border around a component. Borders in JPanel Example import java.awt.*; import javax.swing.*; import javax.swing.border.*; import java.awt.event.*; public class VariousBorders extends JPanel { Border border; JButton butn; […]

BorderLayout  divides the container into five parts (directions),east,west,north,south,centre. By using this Layout we can place AWT components in each part (different location). BORDER LAYOUT IN JAVA EXAMPLE import java.awt.*; import java.applet.*; public class bordr extends Applet { Button b1,b2,b3,b4,b5; public void init() { b1=new Button(“east”); b1.setBackground(Color.RED); b2=new Button(“west”); b2.setBackground(Color.GREEN); b3=new Button(“south”); b3.setBackground(Color.BLACK); b4=new Button(“north”); b4.setBackground(Color.BLUE); […]