Question

I’m doing a project (something like a restaurant) for collage, and I’m not very good in Java (they didn’t really try to teach us). The principle of the project is to show a message saying what radio buttons and check boxes I’ve selected.

I have 5 radio buttons, they are for selecting a meal, and 5 check boxes for selecting a side dish. I’ve managed to have the radio buttons work but I don’t know how to make the check boxes work…

This is the code for the radio buttons (this goes for all 5):

 private void jRadioButton1ItemStateChanged(java.awt.event.ItemEvent evt) {

        if (evt.getSource().equals(jRadioButton1))
        {
            Meal= jRadioButton1.getText(); //Meal is a String
        }

I tried the same code for the check boxes but it only shows one side dish in the message, even though I selected multiple...

The code for the button that shows the message:

 private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {

        JOptionPane.showMessageDialog(rootPane, "You have chosen:\n" + String.valueOf(Meal) + "\n" + String.valueOf(SideDish));
    }

So basically, if anyone is willing to help, please tell me how to make the check boxes work... that every selected check box is shown in the message, like this:

You have chosen:
Pizza //meal
Ketchup //selected side dish #1
Chilli peppers //selected side dish #2
Feta cheese //selected side dish #3

I hope my question is clear...

Answer 1

Since you want to display text for zero or more checkboxes, you need to check for each whether it is selected, and concatenate the resulting text, instead of keeping only one option. Moreover, since check boxes can be checked and unchecked independently, it may be better to check their state only at the moment when the button is pressed instead of attempting to keep track of them all the time. E.g.:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {

  SideDish = "";
  if (jCheckBox1.getState()))
  {
    SideDish += jCheckBox1.getText();
  }
  ...
  if (jCheckBox5.getState()))
  {
    SideDish += ", " + jCheckBox5.getText();
  }

  JOptionPane.showMessageDialog(rootPane, "You have chosen:\n" + Meal + "\n" + SideDish);
}

This is just an illustration, which won’t always display separating commas properly – I will leave the fix to you as an exercise 🙂

A more elegant solution would be to use a collection of Strings to collect the side dishes – again, you may try improving the code towards this.

Btw, you don’t need String.valueOf() to print Strings so I removed it from the code above. And the Java coding convention is to start variable/field names with lowercase.