Passing arguments

Question

Our teacher just taught us about methods and passing arguments, etc. I have been over our text book and I don't quite understand how it works. Any help?
PROBLEM:
?     Write a program with four methods. One is the main method. The other three are named startMessage, message, and finishMessage.
?     Within the startMessage method, place code to print out the message ?The program has started.?
?     Within the message method, place code to print out any message that is passed, as a String, into the method using a String parameter named output.
?     Within the finishMessage method, place code to print out the message ?The program is done.?
?     When the program begins call the startMessage method.
?     Then display the following dialog box:
"Enter a message:"
?     Using a While loop, respond to the user?s input appropriately:
     If the user presses OK display whatever the user has entered by calling the message method with the user?s input as the argument. Continue to display the dialog box and display the user?s input until they press Cancel.
     When the user presses Cancel stop showing the dialog box, and do not display what the user has entered.
?     After the user presses Cancel, and before the program terminates, call the finishMessage method.
?     Terminate the program.
here is what I have so far:
public static void main(String[] args) {
          startMessage();
          String userMessage = JOptionPane.showInputDialog("Enter a message:");
          while (userMessage != null){
               message(userMessage);
               JOptionPane.showMessageDialog(null, "Here is message" + message());
               userMessage = JOptionPane.showInputDialog("Enter a message:");
          finishMessage();
          System.exit(0);
     public static void startMessage(){
          JOptionPane.showMessageDialog(null, "The program has started.");
     public static String message (String output){
          output = userMessage;
          return(output);
     public static void finishMessage(){
          JOptionPane.showMessageDialog(null, "The program is done.");
}what's giving me the problem is the message method; I can't figure out how to pass whatever they put in the userMessage variable to the message method

Answer 1

I am stuck here
PROBLEM:
?     Change your C6E2 class by adding a new method called getNumberInput. This method will be used to get a number input from the user, replacing the lines of code in the main method that were previously used. You will need to call this method twice from the main method, prompting for the first and second numbers in turn.
?     Write the method so that the prompt displayed in the input dialog box is passed through an argument.
?     The return type of this new method will be a double.
I can't figure out how to pass the input paramater correctly, any help?
public static void main(String[] args) {
          double num1 = 0;
          double num2 = 0;
          double addResult = 0;
          double subtractResult = 0;
          double multiplyResult = 0;
          double divideResult = 0;
          double input1 = getNumberInput(num1);//this is where I am stuck
          double input2 = getNumberInput(num2);
          addResult = add(num1, num2);
          subtractResult = subtract(num1, num2);
          multiplyResult = multiply(num1, num2);
          divideResult = divide(num1, num2);
          JOptionPane.showMessageDialog(null, addResult);
          JOptionPane.showMessageDialog(null, subtractResult);
          JOptionPane.showMessageDialog(null, multiplyResult);
          JOptionPane.showMessageDialog(null, divideResult);
          System.exit(0);
     }//main
     public static double getNumberInput (double input){
          double output = 0;
          Double.parseDouble(JOptionPane.showInputDialog("Enter a number:"));
          return output;
     public static double add (double term1, double term2){
          double result = term1 + term2;
          return result;
     }//add
     public static double subtract (double term1, double term2){
          double result = term1 - term2;
          return result;
     }//subtract
     public static double multiply (double term1, double term2){
          double result = term1 * term2;
          return result;
     }//multiply
     public static double divide (double term1, double term2){
          double result = term1 / term2;
          return result;
     }//divide
}//class