Java Notes

Conversions:

String str;
double d;
int i;
char ch;
str = JOptionPane.showInputDialog
	(null,"Enter Integer Number");
i = Integer.parseInt(str);
str = JOptionPane.showInputDialog
	(null,"Enter Double Number");
d = Double.parseDouble(str);
str = JOptionPane.showInputDialog
	(null,"Enter Character");
ch = str.charAt(0);

Listeners:

To make a Java GUI program listen:
Step 1:
  import java.awt.event.*; // at top
Step B:
  implements ActionListener // add to class
Step three:
  panicButton.addActionListener(this); // add to constructor
Step IV:
  public void actionPerformed(ActionEvent e) {
    if(e.getSource() == panicButton) {
      txtAction.setText("Aaaaaggggg...");
    }
  }

Swing:

import javax.swing.*;
public class Main {
	// read String s from inputbox:
	s = JOptionPane.showInputDialog(null,"Enter Fahrenheit Temperature");
	// convert s to float f:
	f = Double.parseDouble(s);
	// display messagebox output:
	JOptionPane.showMessageDialog(null,f + " F = " + c + " C");
}

Java Applets:

HTML for Java Applets:

<html>
<head>
<title>Title of Your Web Page - Shows on Title Bar</title>
</head>
<body>
<applet code="fileName.class" width="400" height="200">
</applet>
</body>
</html>