
import javax.swing.*;

public class TestGui {

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

        JTextField input = new JTextField();
        input.setBounds(10, 10, 200, 40);
        f.add(input);

        JLabel result = new JLabel("result: not available");
        result.setBounds(10, 50, 200, 40);
        f.add(result);

        JButton button = new JButton("square root");
        button.setBounds(10, 90, 200, 40);
        button.addActionListener(e -> {
            String input_str = input.getText();
            double input_number = Double.parseDouble(input_str);
            double result_number = Math.sqrt(input_number);
            result.setText(Double.toString(result_number));
        });
        f.add(button);

        f.setSize(400, 500);
        f.setLayout(null);
        f.setVisible(true);
    }
}


