Errors with my ButtonListener Dial program

Question

I'm just trying to figure out why these errors are popping up. I'm not exactly sure why it is saying varibles not found or why it won't let me add or subtract an int.

Here are the errors:

         javac Dial2.java
 Dial2.java:53: cannot find symbol
symbol  : class arrl
location: class DialFrame
b.addActionListener(new arrl());
                        ^
Dial2.java:56: b is already defined in DialFrame(java.lang.String)
Button b = new Button("<");
       ^
Dial2.java:57: cannot find symbol
symbol  : class arrl
location: class DialFrame
b.addActionListener(new arrl());
                        ^
Dial2.java:127: cannot find symbol
symbol  : variable pastNumbeCount
location: class DialFrame.ArrowListener
    arrowIndex = (arrowIndex + pastNumbeCount - 1) % pastNumberCount;
                               ^
Dial2.java:127: operator + cannot be applied to int,pastNumbeCount
    arrowIndex = (arrowIndex + pastNumbeCount - 1) % pastNumberCount;
                  ^
Dial2.java:127: operator - cannot be applied to <nulltype>,int
    arrowIndex = (arrowIndex + pastNumbeCount - 1) % pastNumberCount;
                                              ^
Dial2.java:128: cannot find symbol
symbol  : variable arrowindex
location: class DialFrame.ArrowListener
    phoneNumber.setText(pastNumbers[arrowindex - 1]);
                                    ^
Dial2.java:133: cannot find symbol
symbol  : variable pastNumberindex
location: class DialFrame.ArrowListener
    phoneNumber.setText(pastNumberindex);
                        ^
8 errors

And here is the code for a simple phone dialer:

cat Dial2.java
import java.awt.*;
import java.awt.event.*;

// Driver class
public class Dial2 {

public static void main(String[] args) {
Frame frame = new DialFrame("Dial");
frame.pack();
frame.setVisible(true);
}
}

// Frame class
class DialFrame extends Frame {
private TextField phoneNumber = new TextField();
private String pastNumbers[] = new String[10];
private int pastNumberCount = 0;
private int pastNumberIndex = 0;
private int arrowIndex = 0;

// Constructor
public DialFrame(String title) {
// Set title
super(title);

// set all pastNumbers to empty string
for (int x = 0; x < pastNumbers.length; x++)
  pastNumbers[x] = "";

// Make text field non-editable and put at top of frame
phoneNumber.setEditable(false);
add("North", phoneNumber);

// Create panel to hold buttons and set its layout
Panel buttonPanel = new Panel();
buttonPanel.setLayout(new GridLayout(4, 3, 10, 10));

DigitListener dl = new DigitListener();
ArrowListener arrl = new ArrowListener();

// Create first nine buttons, attach a listener to each,
// and add buttons to buttonPanel
for (int i = 1; i <= 9; i++) {
  Button b = new Button(i + "");
  b.addActionListener(dl);
  buttonPanel.add(b);
}

// **1** Add your two new buttons to your panel, along with an
//       an arrow listener for both
Button b = new Button(">");
b.addActionListener(new arrl());

b = new Button("0");
Button b = new Button("<");
b.addActionListener(new arrl());
buttonPanel.add(b);



// Create a panel to hold buttonPanel; put it at the
// center of the frame
Panel centerPanel = new Panel();
centerPanel.add(buttonPanel);
add("Center", centerPanel);

// Create a panel to hold the "Dial" button; put it at
// the bottom of the frame
Panel bottomPanel = new Panel();
b = new Button("Dial");
b.addActionListener(new DialListener());
bottomPanel.add(b);
add("South", bottomPanel);

// Attach window listener
addWindowListener(new WindowCloser());
}

private void addPastNumber(String num) {
boolean numberAlreadyAdded = false;
for (int x=0; x < pastNumbers.length; x++) {
  if (pastNumbers[x].equals(num)) {
    numberAlreadyAdded = true;  break;
  }
}
if (!numberAlreadyAdded) {
  pastNumbers[pastNumberIndex] = num;
  pastNumberIndex++;
  if (pastNumberCount < 10) pastNumberCount++;
  if (pastNumberIndex == pastNumbers.length) pastNumberIndex = 0;
}
arrowIndex = pastNumberIndex;
}  

 // Listener for all buttons
class DigitListener implements ActionListener {
public void actionPerformed(ActionEvent evt) {
  String buttonLabel = evt.getActionCommand();
  // append the digit on the newly pressed key
  phoneNumber.setText(phoneNumber.getText() + buttonLabel);
}
}

// Listener for all buttons
class DialListener implements ActionListener {
public void actionPerformed(ActionEvent evt) {
  addPastNumber(phoneNumber.getText());
  phoneNumber.setText("Dialing...");
  // pause for two seconds, or 2000 millisecond  
  try {
    Thread.sleep(2000);
  } catch (InterruptedException e) {}
  phoneNumber.setText("");
}
}

// Listener for "arrow" buttons
class ArrowListener implements ActionListener {
public void actionPerformed(ActionEvent evt) {

  // ** 2 **
String buttonLabel = evt.getActionCommand();

if (buttonLabel == "<")
{
    arrowIndex = (arrowIndex + pastNumbeCount - 1) % pastNumberCount;
    phoneNumber.setText(pastNumbers[arrowindex - 1]);
}
else
{
    arrowIndex = (arrowIndex + 1) % pastNumberCount;
    phoneNumber.setText(pastNumberindex);
}








}
}

 // Listener for window
class WindowCloser extends WindowAdapter {
public void windowClosing(WindowEvent evt) {
  System.exit(0);
}
}
}

Any help or information would be appreciated.

Instructions: If the current index within out pastNumbers array is 9, the number stored at index 0 will be displayed if the ">" key is pressed. If the current index is 0, the number stored at index 9 will be displayed if the "<" key is pressed.

To set this up, I need to retrieve the label from my button. If it is the "<" key, set my arrow index to : (arrowIndex + pastNumberCount - 1) % pastNumberCount; and add the past number at this index in my array of past numbers to my phoneNumber text field.

Otherwise, i need to set my array index to : (arrowIndex + 1) % pastNumberCount, and add the past number at this index to your text field.

Answer 1

Use new ArrowListener() instead of new arrl(); (arrl is not a class, its a object) Use pastNumberCount instead of pastNumbeCount (r missing) Use arrowIndex instead of arrowindex (i should be capital) Use pastNumberIndex instead of pastNumberindex (i should be capital)

There are lot of typos in your program.

Regards, Yash