PhoneBook Record

[Nezura]

Hi guys, this is a phonebook record i've created, the first menu runs, but when the button "enter data" is clicked it gives a NullPointerException, i've tried moving all the variables so it's global but it doesn't seem to be working either, can someone help me out?

code:

//Created by na //Computer Science ISP //Last modified: January 13, 2005 import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.io.*; import java.text.*; public class phonebook extends JApplet implements ActionListener {     //JButton[] buttons = new JButton [5];     int numbercounter = 2; //counts the number of entries the user will make     Container panel = new Container ();     JButton EnterData = new JButton ("Enter Data"); //Button to enter Data     JFrame FirstFrame = new JFrame ("PhoneBook Storage"); //main frame with the 3 starting options     JButton ShowChart = new JButton ("Show Table"); //Button display chart of data     JButton Exit = new JButton ("Close"); //button to exit program     JButton[] buttons = new JButton [numbercounter];     JFrame TypeWindowFrame = new JFrame ("Enter Your Data"); //Frame that you can enter your data into     Container TypeWindow = new Container ();     public void init ()     {         panel.setLayout (new GridBagLayout ());         GridBagConstraints c = new GridBagConstraints ();         JLabel PhoneBook = new JLabel ("  Personal PhoneBook"); //Stores the title PhoneBook         c.ipadx = 5;         c.ipady = 1;         c.fill = GridBagConstraints.BOTH;         c.weightx = 1.0;         c.weighty = 1.0;         c.gridx = 0;         c.gridy = 0;         panel.add (PhoneBook, c);         c.gridx = 0;         c.gridy = 1;         panel.add (EnterData, c);         c.gridx = 0;         c.gridy = 2;         panel.add (ShowChart, c);         c.gridx = 0;         c.gridy = 3;         panel.add (Exit, c);         EnterData.addActionListener (this);         ShowChart.addActionListener (this);         Exit.addActionListener (this);         PhoneBook.setForeground (Color.red);         PhoneBook.setBackground (Color.black);         PhoneBook.setOpaque (true);         EnterData.setForeground (Color.black);         EnterData.setBackground (Color.yellow);         EnterData.setOpaque (true);         ShowChart.setForeground (Color.black);         ShowChart.setBackground (Color.yellow);         ShowChart.setOpaque (true);         Exit.setForeground (Color.black);         Exit.setBackground (Color.yellow);         Exit.setOpaque (true);         FirstFrame.setSize (140, 250);         FirstFrame.getContentPane ().add (panel);         FirstFrame.setVisible (true);     }     public void actionPerformed (ActionEvent e)     {         //------------------------------------Enter Data Frame-----------------------------------------         TypeWindow.setLayout (new GridBagLayout ());         GridBagConstraints d = new GridBagConstraints ();         JLabel PleaseEnter = new JLabel ("  Enter data in the fields below"); //Stores the title instructions         d.ipadx = 5;         d.ipady = 1;         d.fill = GridBagConstraints.BOTH;         d.weightx = 1.0;         d.weighty = 1.0;         d.gridx = 0;         d.gridy = 0;         TypeWindow.add (PleaseEnter, d);         for (int x = 0 ; x < numbercounter ; x++)         {             d.gridx = x;             d.gridy = 1;             TypeWindow.add (buttons [x], d);         }         TypeWindowFrame.setSize (500, 500);         TypeWindowFrame.getContentPane ().add (TypeWindow); //adds the container to the new frame         TypeWindowFrame.setVisible (false); //sets the frame invisible         //-----------------------------------Show Chart Frame------------------------------------------         //-----------------------------------Exit -----------------------------------------------------         if (e.getSource () == EnterData)         {             FirstFrame.setVisible (false);             TypeWindowFrame.setVisible (true); //sets the Enter data  frame visible after the person clicks         }         else if (e.getSource () == ShowChart)         {             FirstFrame.setVisible (false);             TypeWindowFrame.setVisible (true); //sets the showchart frame visible after the person clicks         }         else if (e.getSource () == Exit)         {             FirstFrame.setVisible (false);             TypeWindowFrame.setVisible (true); //sets the exit frame visible after the person clicks         }  } }

[wtd]

A note: in Java, do not begin the names of variables with capital letters.

Names like "PhoneBook" should only be used for classes. More approriate would be, "phoneBook".

In the same vein, "phonebook" is a bad name for a class. Instead use "PhoneBook".

[Nezura]

thx, but that doesn't solve my problem,

err would it be the number counter causing the problem?

[rizzix]

u haven't explained ur problem.

[Hikaru79]

rizzix wrote:

u haven't explained ur problem.

He has, just not well.

Nezura, you say you get a NullPointerException, but that's not descriptive enough. Give us the entire error output that you recieve (a "stack trace") as that will tell us at what line the exception was thrown, and where inside the Java code it failed. Just recreate the error and put everything between [ code ] tags.

[Nezura]

Hey guys, i figuired out the problem...hehe thx for the input