Thread: how do i get the answer to appear in textFieldD (line 92)

import java.awt.EventQueue;
 
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
 
 
public class Week02 {
 
	private JFrame frame;
	private JTextField textFieldA;
	private JTextField textFieldB;
	private JTextField textFieldC;
	private JTextField textFieldD;
	private JButton btnNewButton;
 
	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					Week02 window = new Week02();
					window.frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}
 
	/**
	 * Create the application.
	 */
	public Week02() {
		initialize();
	}
 
	/**
	 * Initialize the contents of the frame.
	 */
	private void initialize() {
		frame = new JFrame();
		frame.setBounds(100, 100, 546, 412);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.getContentPane().setLayout(null);
 
		textFieldA = new JTextField();
		textFieldA.setBounds(30, 31, 173, 53);
		frame.getContentPane().add(textFieldA);
		textFieldA.setColumns(10);
 
		textFieldB = new JTextField();
		textFieldB.setBounds(30, 119, 173, 53);
		frame.getContentPane().add(textFieldB);
		textFieldB.setColumns(10);
 
		textFieldC = new JTextField();
		textFieldC.setBounds(30, 206, 173, 58);
		frame.getContentPane().add(textFieldC);
		textFieldC.setColumns(10);
 
		textFieldD = new JTextField();
		textFieldD.setEditable(false);
		textFieldD.setBounds(30, 288, 173, 53);
		frame.getContentPane().add(textFieldD);
		textFieldD.setColumns(10);
 
		JButton compute = new JButton("Compute");
		compute.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				String Input;
				double textFieldA;
				double textFieldB;
				double textFieldC;
				double textFieldD;
				double Add;
				double Multiply;
				double Divide;
				double Subtract;
 
				if (textFieldC == Add) {
 
					double a, b, c;
					a = Double.parseDouble(Input);
					b = Double.parseDouble(Input);
					c = a + b;
					textFieldD (+ c); //how do we send the answer to textFieldD???? this method isn't working
				}
 
			}
		});
		compute.setBounds(233, 224, 139, 29);
		frame.getContentPane().add(compute);
 
		btnNewButton = new JButton("Instructions");
		btnNewButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				JOptionPane.showMessageDialog(null, "All possable imputs \n" +
						"Add \n" +
						"Subtract \n" +
						"Multiply \n" +
						"Divide \n");
			}
		});
		btnNewButton.setBounds(382, 224, 123, 29);
		frame.getContentPane().add(btnNewButton);
	}
}

i wrapped the code. i really don't know what that line needs to be to display the answer in a textfield. :/

what if i dont know what class?