EXAMPLES FOR DAY 1 (Day1.txt file)

// Example HelloWorld
// Class Greeting
// Print the message "Hello, World." when
// the static method main executes.

public class Greeting
{
    public static void main(String[] args)
    {
	System.out.println("Hello, world.");
    }	
}

' *******************


// Project JOptionPane
// Class Greeting2
// Ask user for name, 
// then greet that person.

import javax.swing.JOptionPane;

public class Greeting2
{
    public static void main(String[] args)
    {
	// Declare name.
	String name;

	// Ask for name in input box.
	name = JOptionPane.showInputDialog("Enter your name.");

	// Show message box with greeting.
	JOptionPane.showMessageDialog(null, "Hello, " + name + ".");
    }
}

' *******************

// Project Coin
// Class CoinTest
// Call the Coin constructor and
// Flip the coin three times.

public class CoinTest
{
    public static void main(String[] args)
    {
	Coin coin;
	int i;

	coin = new Coin();
	System.out.println("Initial value = " + coin);

	// First flip		
  	coin.flip();
	System.out.println("Flip 1 = " + coin);		

	// Second flip		
  	coin.flip();
	System.out.println("Flip 2 = " + coin);		

	// Third flip.		
  	coin.flip();
	System.out.println("Flip 3 = " + coin);

	// New line.
	System.out.println();
    }
}

' -------------------

// Project Coin
// Class Coin
// A coin that can be flipped randomly.

public class Coin
{
	// private instance variable.
	private boolean side;

	// Constructor for Coin.
	public Coin()
	{
		// Flip the coin randomly to
 		// for initial value.
		flip();
	}

	// Flip the coin randomly.
	public void flip()
	{
		side = (Math.random() >= 0.5);
	}

	// Convert a string representation of
	// the side of the coin to be printed.
	public String toString()
	{
		if (side)
			return "head";
		else
			return "tail";
	}
}

' *******************

// Project Applet
// Class Bullseye
// Display a bullseye target.

import java.applet.Applet;
import java.awt.*;

public class Bullseye extends Applet
{
    private final int MAX_WIDTH = 300;
    private final int NUM_RINGS = 5;
    private final int RING_WIDTH = 25;

    // Paint a bullseye target.
    public void paint(Graphics page)
    {
        int x = 0, y = 0, diameter;

	setBackground(Color.cyan);

	diameter = MAX_WIDTH;
	page.setColor(Color.white);
	
	for(int count = 0; count < NUM_RINGS; count++)
	{	
	    // Alternate colors.
	    if(page.getColor() == Color.black)
		page.setColor(Color.white);
	    else
		page.setColor(Color.black);
		
 	    // Draw circle.
	    page.fillOval(x, y, diameter, diameter);

	    diameter -= (2 * RING_WIDTH);
	    x += RING_WIDTH;
	    y += RING_WIDTH;
	}

	// Draw the red bullseye in the center.
	page.setColor(Color.red);
	page.fillOval(x, y, diameter, diameter);
    }
}

' *******************

// Project Controls
// Class TestControls

public class TestControls
{
    public static void main(String[] args)
    {
	Controls frame = new Controls();
    }
}

' -------------------

// Project Controls
// Class Controls
// Create an application that displays common
// user interface controls.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Controls extends JFrame
{
    // Global instance variables that must be visible 
    // in the inner class ButtonListener.
    private JLabel label;
    private JTextField textfield;
    private JCheckBox checkbox;
    private JRadioButton radio1, radio2;
    private JButton button;
    private ButtonGroup radiogroup;

    // constuctor
    public Controls()
    {
	// Set frame caption.
	super("Some User Interface Controls");

	// Set the size of the frame to 
	// width = 300 pixels, height = 150.
	setSize(300, 150);

	// Set the container and layout manager.
	Container c = getContentPane();
	c.setLayout(new FlowLayout());

	// Create controls objects.
	label = new JLabel("TextField");
	textfield = new JTextField(5);
	radio1 = new JRadioButton("Radio Button 1", true);
	radio2 = new JRadioButton("Radio Button 2", false);
	checkbox = new JCheckBox("Check Box", false);
	button = new JButton("Show Values");

	// Create radiogroup object and add radio buttons. 
	radiogroup = new ButtonGroup();
	radiogroup.add(radio1);
	radiogroup.add(radio2);
	
	// Add controls to the container.
	c.add(label);
	c.add(textfield);
	c.add(checkbox);
	c.add(radio1);
	c.add(radio2);
	c.add(button);

	// Create a listener for the button.
	ButtonListener listener = new ButtonListener();

	// Let the listener listen to the button.
	button.addActionListener(listener);

	// Show the frame.
	show();
    }

    // Inner class definition of the listener for the button.
    private class ButtonListener implements ActionListener
    {
	public void actionPerformed (ActionEvent e)
	{
  	    JOptionPane.showMessageDialog(null,
		"TextField Value = " + textfield.getText() +
		"\nCheckBox Value = " + checkbox.isSelected() +
		"\nRadio1 Value = " + radio1.isSelected() +
		"\nRadio2 Value = " + radio2.isSelected() );
	}
    }
}

' *******************

// Project Variables
// Class Variables
// Demonstrate the builtin datatypes in Java.

public class Variables
{
    public static void main(String[] args)
    {
	byte w;       // byte is a 1 byte integer.
	short x;      // short is a 2 byte integer.      
	int y;        // int is a 4 byte integer.
	long z;       // long is an 8 byte integer.

	w = 127;
	x = 20429;
	y = 103733249;
	z = 1000000000000L;  // <-- One trillion.  Trailing L
                             // for long integer constant.
	System.out.println(w + " " + x + " " + y + " " + z);
	System.out.println();

	float s;      // float is a 4 byte floating point.
	double t;     // double is an 8 byte floating point.

	s = 3.546e19F;  // Trailing F for float constant.
	t = 5.42e98;    // Default decimal constant is double.
	System.out.println(s + " " + t);
	System.out.println();

	char letter;  // char contains a 2 byte unicode character. 
  		      // representing an ascii code.
	letter = 'A';
	System.out.println(letter + " " + (int) letter);
	System.out.println();

	String str;   // objects in the String class 
 	 	      // represent strings of characters.
	str = "apple";
	System.out.println(str);
	System.out.println();

	boolean p, q;  // boolean can have values 
		       // false or true.
	p = true;
	q = false;
	System.out.println(p + " " + q);
	System.out.println();
    }
}

' *******************

// Project Operators
// Class Operators

public class Operators
{
    public static void main(String[] args)
    {
	int x = 7, y = 3, a, b, c, d;
	boolean f, g, h, k, m, n, p;

	// Arithmetic operators.
	a = x + y;
	b = x - y;
	c = x * y;
	d = x / y;
	System.out.println(a + " " + b + " " + c + " " + d);

	// Arithmetic assignment operators.
	a += y;
	b -= y;
	c *= y;
	d /= y;
	System.out.println(a + " " + b + " " + c + " " + d);

	// Assignment operator = associates right to left.
	a = b = c = d = 17;
	System.out.println(a + " " + b + " " + c + " " + d);

	// Bitwise operators.
	x = 5;
	y = 13;
	a = x | y;
	b = x & y;
	c = x ^ y;
	d = ~x;
	System.out.println(a + " " + b + " " + c + " " + d);

	// Bitwise assignment operators are available also.
        x = 5;
        y = 13;
        x |= y;
        System.out.println(a + " " + b);

	// Relational operators.
	x = 7;
	y = 3;
	f = (x < y);
	g = (x <= 7);
	h = (x > y);
	k = (x >= y);
	m = (x != 3);
	n = (x == 3);
	p = !f;
	System.out.println(f + " " + g + " " + h + " " + k + " " +
		m + " " + n + " " + p);
	System.out.println();

	// Logical And operator.
	f = false && false;
	g = false && true;
	h = true && false;
	k = true && true;
	System.out.println(f + " " + g + " " + h + " " + k);
	System.out.println();

	// Logical Or operator.
	f = false || false;
	g = false || true;
	h = true || false;
	k = true || true;
	System.out.println(f + " " + g + " " + h + " " + k);
	System.out.println(); 

	// Logical Not operator.
	f = !false;
	g = !true;
	System.out.println(f + " " + g);
	System.out.println();

	// Tertiary conditional operator. In this case z will 
        // contain the minimum of x and y.
	a = 5;
        b = 9;
        c = a < b ? a : b;
	System.out.println(a + " " + b + " " + c);
    }
}