Question

Question 2: Create a very simple temperature converter form having two text fields. The first one is where the user will enter temperature. The second field is where the computed temperature value is displayed depending on the unit (F or C).

Answer 1

Things to consider:

• Here, first of all, we have created all the required fields like labels and text fields.
• After that, whenever when we enter some value to any of the fields either Celsius or Fahrenheit, we are using the formula to convert to the other as can be seen in the program for the conversion.
• Whatever the result is, we are setting it to the corresponding text field.
• Note: Please read the program line by line for better understanding.

Please refer to the comments of the program for more clarity.

// Importing required packages
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

// Extending the JFrame for adding the text fields
public class TempConversion extends JFrame
{
    // initializing the constants
    private static final int WINDOW_WIDTH = 500;
    private static final int HEIGHT = 80;
    private static final double far_to_c = 5.0/9.0;
    private static final double c_to_far = 9.0/5.0;
    private static final int Factor = 32;
    
    // initializing the labels
    private JLabel cLabel;
    private JLabel fLabel;

    // initializing the text fields
    private JTextField cTF;
    private JTextField fTF;
    
    // // initializing the handlers
    private CHandler cHandler;
    private FHandler fHandler;
    
    
    // Function to convert the Celsius to Fahrenheit and vice versa
    public TempConversion()
    {

        // Setting the title
        setTitle("Temperature Converter");
        Container c = getContentPane();

        // Setting the layout
        c.setLayout(new GridLayout(1,4));

        // Providing values to the labels
        cLabel = new JLabel("Temp in C: ",
                SwingConstants.RIGHT);
        fLabel = new JLabel("Temp in F: ",
                SwingConstants.RIGHT);

        // Defining the size of the text field
        cTF = new JTextField(7);
        fTF = new JTextField(7);

        // Adding the components to the container
        c.add(cLabel);
        c.add(cTF);
        c.add(fLabel);
        c.add(fTF);

        // Initializing the handlers
        cHandler = new CHandler();
        fHandler = new FHandler();

        cTF.addActionListener(cHandler);
        fTF.addActionListener(fHandler);

        // Setting the windows size
        setSize (WINDOW_WIDTH, HEIGHT);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    // Handler implementing the Action Listener
    private class CHandler implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            double c, f;

            // Logic of the conversion
            c = Double.parseDouble(cTF.getText());
            f = c * c_to_far + Factor;
            fTF.setText(String.format("%.2f", f));
        }
    }

    // Handler for Fahrenheit implementing the Action Listener
    private class FHandler implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            double c, f;

            // Logic for conversion
            f = Double.parseDouble(fTF.getText());
            c = (f - Factor) * far_to_c;
            cTF.setText(String.format("%.2f", c));
        }
    }


    // Main method or the starting point of the program.
    public static void main(String[] args)
    {
        TempConversion t = new TempConversion();
        t.setLocationRelativeTo(null);
    }
}
 

Sample Input-Output/CodeRun - 1:

Sample Input-Output/CodeRun - 2:

Please let me know in the comments in case of any confusion. Also, please upvote if you like.