// Fig. 3.12: javac // Adding two floating-point numbers. // Java core packages import java.awt.Graphics; // import class Graphics // Java extension packages import javax.swing.*; // import package javax.swing public class AdditionApplet extends JApplet { double sum; // sum of values entered by user // initialize applet by obtaining values from user public void init() { String firstNumber; // first string entered by user String secondNumber; // second string entered by user double number1; // first number to add double number2; // second number to add // obtain first number from user firstNumber = JOptionPane.showInputDialog( "Enter first floating-point value" ); // obtain second number from user secondNumber = JOptionPane.showInputDialog( "Enter second floating-point value" ); // convert numbers from type String to type double number1 = Double.parseDouble( firstNumber ); number2 = Double.parseDouble( secondNumber ); // add numbers sum = number1 + number2; } // draw results in a rectangle on applet background public void paint( Graphics g ) { // call inherited version of method paint super.paint( g ); // draw rectangle starting from (15, 10) that is 270 // pixels wide and 20 pixels tall g.drawRect( 15, 10, 270, 20 ); // draw results as a String at (25, 25) g.drawString( "The sum is " + sum, 25, 25 ); } // end method paint } // end class AdditionApplet