looping a jframe window

Question

I need help with every time a button is pressed and it goes through the validation process, It will increment the index by 1 and will show up on the UI. However, I'm having an issue where, when it get incremented, it won't go up by 1 in the UI and just won't update basically.

index = 1;

JLabel lblNewLabel = new JLabel("test " + index );
testTextField = new JTextField();
frame.getContentPane().add(testTextField, BorderLayout.CENTER);
testTextField.setColumns(10);
testTextField = new JTextField();

nextButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        String txtField = testTextField.getText();
         
        int s = 3; 
        int test = s - 1;
          
        if (txtInvalid(txtField) == false) {
            JOptionPane.showMessageDialog(null, "input valid text field");
        } 
        else {
            JOptionPane.showMessageDialog(null, "gratz, onto the next !!");
            index++;
        }
    }
});

Answer 1

You can declare the "index" variable globally or use static keyword. The static variable gets memory only once in the class area at the time of class loading.