What's wrong with this program, nothing displays.

Question

Compile ok, but nothing displays.
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class Card{
JFrame f;
JLabel nameTF;
JComboBox jobChoice;
JButton B1, B2, B3, B4;
public static void main(String[] av) {
new Card( );
public Card( ) {
f=new JFrame();
f.setSize(500,500);
Container cp = f.getContentPane( );
cp.setLayout(new GridLayout(0, 1));
f.addWindowListener(new WindowAdapter( ) {
public void windowClosing(WindowEvent e) {
f.setVisible(false);
f.dispose( );
System.exit(0);
JMenuBar mb = new JMenuBar( );
f.setJMenuBar(mb);
JMenu aMenu;
aMenu = new JMenu("filemenu");
mb.add(aMenu);
JMenuItem mi = new JMenuItem("exit");
aMenu.add(mi);
mi.addActionListener(new ActionListener( ) {
public void actionPerformed(ActionEvent e) {
System.exit(0);
aMenu = new JMenu("editmenu");
mb.add(aMenu);
aMenu = new JMenu("viewmenu");
mb.add(aMenu);
aMenu = new JMenu("optionsmenu");
mb.add(aMenu);
aMenu =new JMenu("helpmenu");
mb.add(aMenu);
JPanel p1 = new JPanel( );
p1.setLayout(new GridLayout(0, 1, 50, 10));
nameTF = new JLabel("My Name", JLabel.CENTER);
nameTF.setFont(new Font("helvetica", Font.BOLD, 18));
nameTF.setText("MYNAME");
p1.add(nameTF);
jobChoice = new JComboBox( );
jobChoice.setFont(new Font("helvetica", Font.BOLD, 14));
String next;
int i=1;
do {
next = "job_title" + i;
if (next != null)
jobChoice.addItem(next);
} while (next != null);
p1.add(jobChoice);
cp.add(p1);
JPanel p2 = new JPanel( );
p2.setLayout(new GridLayout(2, 2, 10, 10));
B1 = new JButton( );
B1.setText("button1.label");
p2.add(B1);
B2 = new JButton( );
B2.setText("button2.label");
p2.add(B2);
B3 = new JButton( );
B3.setText("button3.label");
p2.add(B3);
B4 = new JButton( );
B4.setText("button4.label");
p2.add(B4);
cp.add(p2);
f.pack( );
f.show();
}

Answer 1

hi there
try this code i changed a little bil and one more thing yr LOOP is not working Properly check that out
rest is fine
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class Card extends JFrame
    JLabel nameTF;
    JComboBox jobChoice;
    JButton B1, B2, B3, B4;
    public static void main(String[] av)
        Card C = new Card( );
        C.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    public Card( )
        setSize(500,500);
        Container cp = getContentPane( );
        cp.setLayout(new GridLayout(0, 1));
        addWindowListener(new WindowAdapter( )
            public void windowClosing(WindowEvent e)
                dispose( );
                System.exit(0);
    JMenuBar mb = new JMenuBar( );
    setJMenuBar(mb);
    JMenu aMenu;
    aMenu = new JMenu("filemenu");
    mb.add(aMenu);
    JMenuItem mi = new JMenuItem("exit");
    aMenu.add(mi);
    mi.addActionListener(new ActionListener( )
        public void actionPerformed(ActionEvent e)
            dispose( );
            System.exit(0);
    aMenu = new JMenu("editmenu");
    mb.add(aMenu);
    aMenu = new JMenu("viewmenu");
    mb.add(aMenu);
    aMenu = new JMenu("optionsmenu");
    mb.add(aMenu);
    aMenu =new JMenu("helpmenu");
    mb.add(aMenu);
    JPanel p1 = new JPanel( );
    p1.setLayout(new GridLayout(0, 1, 50, 10));
    nameTF = new JLabel("My Name", JLabel.CENTER);
    nameTF.setFont(new Font("helvetica", Font.BOLD, 18));
    nameTF.setText("MYNAME");
    p1.add(nameTF);
    jobChoice = new JComboBox( );
    jobChoice.setFont(new Font("helvetica", Font.BOLD, 14));
    String next;
//    int i=1;
//    do
//        next = "job_title" + i;
//        if (next != null)
//           jobChoice.addItem(next);
//    } while (next != null);
    p1.add(jobChoice);
    cp.add(p1);
    JPanel p2 = new JPanel( );
    p2.setLayout(new GridLayout(2, 2, 10, 10));
    B1 = new JButton( );
    B1.setText("button1.label");
    p2.add(B1);
    B2 = new JButton( );
    B2.setText("button2.label");
    p2.add(B2);
    B3 = new JButton( );
    B3.setText("button3.label");
    p2.add(B3);
    B4 = new JButton( );
    B4.setText("button4.label");
    p2.add(B4);
    cp.add(p2);
    pack( );
    setVisible(true);
}Regards
Satinderjit