unit conventer.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class GUI extends JFrame{
    JLabel unit= new JLabel("calculator");
    JTextField input = new JTextField("Enter the number you want to convert it.");
    JTextField output = new JTextField("the result will be displayed here.");
    String units [] ={"centimeter","meter"};
    JComboBox typeOne = new JComboBox(units);
    JComboBox typeTwo = new JComboBox(units);
    JButton convert = new JButton("Convert");
    JButton clear = new JButton("Clear");
    JLabel space = new JLabel("                                                                                                 Unit");
    JPanel nor = new JPanel(new GridLayout(1,3));
    JPanel cen = new JPanel(new GridLayout(2,2));
    JPanel bot = new JPanel(new GridLayout(1,4));
    JTextArea border = new JTextArea("Hiiiiiiiiiiiii");
    JTextArea border2 =new JTextArea("Hiiiiiiiiiiiii");
    JLabel space2 = new JLabel();
    JLabel space3= new JLabel();
    JLabel space4 = new JLabel();
    JLabel space5 = new JLabel();
    JLabel space6 = new JLabel();
    JLabel space7 = new JLabel();




    public  GUI(){
        nor.add(space);
        nor.add(unit);
        cen.add(input);
        cen.add(output);
        cen.add(typeOne);
        cen.add(typeTwo);
        bot.add(space2,BorderLayout.WEST);//wow, you can use borderlayout.west with a grid layout
        bot.add(convert);
        bot.add(clear);
        bot.add(space7,BorderLayout.WEST);
        add(nor,BorderLayout.NORTH);
        add(cen,BorderLayout.CENTER);
        add(bot,BorderLayout.SOUTH);
        add(border,BorderLayout.EAST);
        add(border2,BorderLayout.WEST);
        convert.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                String in = (String) typeOne.getSelectedItem();
                String out = (String) typeTwo.getSelectedItem();
                double inNum = Double.parseDouble(input.getText());
                double result;

                if (in.equals("centimeter")&&out.equals("meter")){
                    result = inNum/100;
                    output.setText(result+"");
                }
                if (in.equals("meter")&&out.equals("meter")){
                    result = inNum;
                    output.setText(result+"");
                }
                if (in.equals("centimeter")&&out.equals("centimeter")){
                    result = inNum;
                    output.setText(result+"");
                }
                if (in.equals("meter")&&out.equals("centimeter")){
                    result = inNum * 100;
                    output.setText(result+"");
                }
            }
        });

        setVisible(true);
        setSize(650,300);
        setLocationRelativeTo(null);
        setTitle("Unit Calculator");
        setDefaultCloseOperation(EXIT_ON_CLOSE);

    }
}