Question

I have following Java code:

JFrame frame = new JFrame();
frame.setTitle("Sudoku");
frame.setLocationRelativeTo(null);
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
frame.getContentPane().add(ruudustik.peaRuudustik()); //returns JPanel with textfields inside
frame.setVisible(true);

ruudustik.peaRuudustik function:

public static JPanel peaRuudustik() {
    JPanel panel = new JPanel();
    for (int i = 0; i < 81; i++) {
        final JTextField ruut = new JTextField();
        ruut.setHorizontalAlignment(JTextField.CENTER);
        ruut.setSize(30, 30);
        ruut.setColumns(1);
        ruut.setName(Integer.toString(i));
        panel.add(ruut);
    }
    return panel;
}

How can i change specific textfield value. Every textfield has unique name.

Answer 1

You could iterate over panel subcomponents, but I recommend another approach – use a Map, for example:

Map<Integer, JComponent> textFields = new HashMap<Integer, JTextField>();
...
textFields.put(i, ruut);
ruut.setName(Integer.toString(i));
panel.add(ruut);

Then, access the components simply by textFields.get(id);