JMenu help

[Kyle227]

the program was working fine until i added some menus. it showed no errors in the program itself but in the console these errors showed.

Exception in thread "main" java.lang.NullPointerException
at Converter.<init>(Converter.java:54)
at Converter.main(Converter.java:224)

here is the code

import javax.swing.JFrame;
import javax.swing.*;
import java.awt.*;


public class Converter extends JFrame {
	// menu
	JMenuBar bar;
	JMenu menu;
	JMenuItem resetapp;
	JMenuItem exit;
	JMenu help;
	// buttons
	JButton clear;
	// US measurements 
	JTextField inch2feet;
	JTextField feet2inch;
	JTextField yard2feet;
	JTextField feet2yard;
	JTextField mile2yard;
	JTextField yard2mile;
	// metric measurements
	JTextField cm2mm;
	JTextField mm2cm;
	JTextField m2cm;
	JTextField cm2m;
	JTextField km2m;
	JTextField m2km;
	//both us and metric;
	JTextField inch2meter;
	JTextField meter2inch;
	JTextField feet2meter;
	JTextField meter2feet;
	JTextField yard2meter;
	JTextField meter2yard;
	//other
	JTextField fahrenheit2c;
	JTextField celcius2h;
	 

	
	public Converter() {
		super("Converter");
		setSize(375,700);
		GridLayout flow = new GridLayout(16,4);
		setLayout(flow);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		menu = new JMenu("File");
		help = new JMenu("Help");
		resetapp = new JMenuItem("Reset");
		exit = new JMenuItem("Exit");
		menu.add(resetapp);
		menu.add(exit);
		bar.add(menu);
		bar.add(help);
		add(bar);
		setVisible(true);
		
		//row 0
		JPanel row0 = new JPanel();
		clear = new JButton("reset");
		row0.add(clear);
		add(row0);
		
		JLabel US = new JLabel("US Measurements");
		add(US);
		
		//row 1
		JPanel row1 = new JPanel();
		JLabel in = new JLabel("Inches:");
		row1.add(in);
		inch2feet = new JTextField(10);
		inch2meter = new JTextField(10);
		row1.add(inch2feet);
		JLabel ft = new JLabel("Feet:");
		row1.add(ft);
		feet2inch = new JTextField(10);
		row1.add(feet2inch);
		add(row1);
		
		//row 2
		JPanel row2 = new JPanel();
		JLabel ft2 = new JLabel("Feet:");
		row2.add(ft2);
		feet2yard = new JTextField(10);
		row2.add(feet2yard);
		JLabel yd = new JLabel("Yard:");
		row2.add(yd);
		yard2feet = new JTextField(10);
		row2.add(yard2feet);
		add(row2);
		
		//row 3
		JPanel row3 = new JPanel();
		JLabel yd2 = new JLabel("Yard:");
		row3.add(yd2);
		yard2mile = new JTextField(10);
		row3.add(yard2mile);
		JLabel mile = new JLabel("Mile:");
		row3.add(mile);
		mile2yard = new JTextField(10);
		row3.add(mile2yard);
		add(row3);
		
		JLabel metric = new JLabel("Metric Measurements");
		add(metric);
		
		//row 4
		JPanel row4 = new JPanel();
		JLabel cm = new JLabel("mm:");
		row4.add(cm);
		mm2cm = new JTextField(10);
		row4.add(mm2cm);
		JLabel mm = new JLabel("cm:");
		row4.add(mm);
		cm2mm = new JTextField(10);
		row4.add(cm2mm);
		add(row4);
		
		//row 5
		JPanel row5 = new JPanel();
		JLabel cm2 = new JLabel("cm:");
		row5.add(cm2);
		cm2m = new JTextField(10);
		row5.add(cm2m);
		JLabel m = new JLabel("Meter:");
		row5.add(m);
		m2cm = new JTextField(10);
		row5.add(m2cm);
		add(row5);
		
		//row 6
		JPanel row6 = new JPanel();
		JLabel m2 = new JLabel("Meter:");
		row6.add(m2);
		m2km = new JTextField(10);
		row6.add(m2km);
		JLabel km = new JLabel("km:");
		row6.add(km);
		km2m = new JTextField(10);
		row6.add(km2m);
		add(row6);
		
		JLabel both = new JLabel("US and Metric conversion");
		add(both);
		
		//row 7
		JPanel row7 = new JPanel();
		JLabel in3 = new JLabel("Inches:");
		row7.add(in3);
		inch2meter = new JTextField(10);
		row7.add(inch2meter);
		JLabel m3 = new JLabel("Meter:");
		row7.add(m3);
		meter2inch = new JTextField(10);
		row7.add(meter2inch);
		add(row7);
		
		//row 8
		JPanel row8 = new JPanel();
		JLabel ft3 = new JLabel("Feet:");
		row8.add(ft3);
		feet2meter = new JTextField(10);
		row8.add(feet2meter);
		JLabel m4 = new JLabel("Meter:");
		row8.add(m4);
		meter2feet = new JTextField(10);
		row8.add(meter2feet);
		add(row8);
		
		//row 9
		JPanel row9 = new JPanel();
		JLabel yd3 = new JLabel("Yard:");
		row9.add(yd3);
		yard2meter = new JTextField(10);
		row9.add(yard2meter);
		JLabel m5 = new JLabel("Meter:");
		row9.add(m5);
		meter2yard = new JTextField(10);
		row9.add(meter2yard);
		add(row9);
		
		JLabel other = new JLabel("Other");
		add(other);
		
		//row 10
		JPanel row10 = new JPanel();
		JLabel far = new JLabel("Fahrenheit");
		row10.add(far);
		fahrenheit2c = new JTextField(10);
		row10.add(fahrenheit2c);
		JLabel cel = new JLabel("Celcius");
		row10.add(cel);
		celcius2h = new JTextField(10);
		row10.add(celcius2h);
		add(row10);
		
		Handler ch = new Handler(this);
		 inch2feet.addActionListener(ch);
		 feet2inch.addActionListener(ch);
		 yard2feet.addActionListener(ch);
		 feet2yard.addActionListener(ch);
		 mile2yard.addActionListener(ch);
		 yard2mile.addActionListener(ch);
		 cm2mm.addActionListener(ch);
		 mm2cm.addActionListener(ch);
		 m2cm.addActionListener(ch);
		 cm2m.addActionListener(ch);
		 km2m.addActionListener(ch);
		 m2km.addActionListener(ch);
		 inch2meter.addActionListener(ch);
		 meter2inch.addActionListener(ch);
		 feet2meter.addActionListener(ch);
		 meter2feet.addActionListener(ch);
		 yard2meter.addActionListener(ch);
		 meter2yard.addActionListener(ch);
		 fahrenheit2c.addActionListener(ch);
		 celcius2h.addActionListener(ch);
		 clear.addActionListener(ch);
		
	}
	
	public static void main(String[] args) {
		Converter ct = new Converter();
	}
	

}

one of the errors is in line 54

bar.add(menu);

the other is in line 224

Converter ct = new Converter();

what did i do wrong.

[curmudgeon]

bar.add(menu);

So bar must be null. Look back at where you declare and initialize it.

[Kyle227]

thanks a lot

[curmudgeon]

You are welcome.