`Add1' example program: add two numbers
Add1.java

// Add1.java
// A program that adds 2 and 2 
// Kevin Boone, May 1999

// Like most programs that use applets, we need the following
//  two lines to tell the compiler what an applet is
//  and how it works. 

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

// As in all Java programs we have to define a class. I am
//  calling this class `Add1', so this program must be
//  in a file called `Add1.java' 

public class Add1 extends Applet
{
public void paint (Graphics g)
	{
	// ``int'' is short for `integer', meaning a whole number.
	// So this line defines a thing called ``result'' which stores
	//  the result of adding 2 and 2.
	int result = 2 + 2;
	
	// The next line displays the text ``2+2='' on the screen
	g.drawString ("2+2=", 20, 20);

	// This line displays the result of the addition on the
	//  next line.
	g.drawString (Integer.toString(result), 20, 40);
	}
}