At a loss on where to go on this code

Question

I am trying to write program that computes fahrenheit into celcius with input from a dialog box. Here is what I have so far. I have tried other things but nothing work and I am at my wits end.
Please help.
// ComputeCelsius.java: Convert Fahrenheit into Celsius
import javax.swing.JOptionPane;
public class ComputeCelsius {
/** Main Method*/
public static void main(String[] args) {
double fahrenheit; // Amount entered from the keyboard
//Recieve the amount entered into the keyboard
String fahrenheitString = JOptionPane.showInputDialog(null,
"Enter fahrenheit","for example 99",
JOptionPane.QUESTION_MESSAGE);
// Convert string to double
fahrenheit = Double.parseDouble(fahrenheitString);
// Compute celcius
Celsius = (5.0/ 9) * (fahrenheit - 32);
//Display the result in a message dialog box
JOptionPane.showInputDialog(null,
fahrenheit + " celsius
}

Answer 1

The DecimalFormat class is a way to control the appearance of the double Celsius that you show, especially the number of decimal places.
import javax.swing.JOptionPane;
public class dlmlucas {
  /** Main Method*/
  public static void main(String[] args) {
    double fahrenheit; // Amount entered from the keyboard
    //Recieve the amount entered into the keyboard
    String fahrenheitString = JOptionPane.showInputDialog(null,
                                  "Enter fahrenheit","for example 99",
                                   JOptionPane.QUESTION_MESSAGE);
    // Convert string to double
    try {
      fahrenheit = Double.parseDouble(fahrenheitString);
    catch(NumberFormatException nfe) {
      System.out.println("NFE: " + nfe.getMessage());
      // error recovery code goes here
      return;
    // Compute celcius
    double Celsius = (5.0/ 9) * (fahrenheit - 32);
    //Display the result in a message dialog box
    JOptionPane.showMessageDialog(null,
                    fahrenheit + " degrees fahrenheit = " +
                    Celsius + " degrees celsius.",
                    "Conversion",
                    JOptionPane.INFORMATION_MESSAGE);
    System.exit(0);
}