CODEWITHSUNDEEP
java
Chocolatto
Chocolatto

Reputation: 63

Testing Set and Get method but it didnt work

I'm trying to test out the Set and Get method, but it didn't seem to work.

I added ActionListener to a button, then perform it when it is clicked. But it didn't work though. In a bigger project, I used this method as well but since it didn't work, I had to simplify it to a smaller program to make it easier to understand. However, I still couldn't understand it. Can you guys help me to point out the problem?

Here is the code:

public class SetAndGet extends JPanel {
private int index = 3500;

private JButton btPrev;
private JLabel lbIndex;

public SetAndGet() {
    init();
}

public int getIndex() {
    return index;
}

public void setIndex(int index) {
    this.index = index;
}

private void init() {
    setLayout(null);
    setBackground(Color.WHITE);

    lbIndex = new JLabel(index + "");
    lbIndex.setBounds(10, 10, 50, 30);
    add(lbIndex);

    btPrev = new JButton("Previous");
    btPrev.setBounds(100, 10, 80, 30);
    btPrev.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            // index--;       THIS ONE WORKED, OF COURSE
            // lbIndex.setText(index + "");

            // BUT THIS ONE DIDNT, PLEASE EXPLAIN FOR ME
            int i = getIndex();
            setIndex(i--);
            lbIndex.setText(index + "");
        }
    });
    add(btPrev);
}

public static void main(String[] args) {
    JFrame f = new JFrame("Test");

    f.setSize(200, 200);
    f.setLocationRelativeTo(null);
    f.addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    });
    f.add(new SetAndGet());
    f.setVisible(true);
}
}

Upvotes: 0

Views: 57

Answers (1)

user9420984
user9420984

Reputation:

Your getter and setter are working, you are just not changing the value. i-- will subtract one from i after it has been assigned to the setter.

If you want to subtract one before setting the value, use --i:

public void actionPerformed(ActionEvent e) {
        // index--;       THIS ONE WORKED, OF COURSE
        // lbIndex.setText(index + "");

        // BUT THIS ONE DIDNT, PLEASE EXPLAIN FOR ME
        int i = getIndex();
        setIndex(--i);
        lbIndex.setText(index + "");
    }

Upvotes: 2

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