ERROR FOR GUI APPLICATION !

Question

This is the code:
import ComplexNumbers;
import Poly;
import Quad;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.ArrayList;
public class QuadGUI
  private int WIDTH = 600;
  private int HEIGHT = 150;
  private JFrame frame;
  private JPanel panel;
  private JLabel in1,in2,in3,out1,out2,result1,result2;
  private JTextField a,b,c;
public  QuadGUI()
  frame = new JFrame("Complex Quadratic Calculator");
  in1 = new JLabel("Enter coefficient a:");
  in2 = new JLabel("Enter coefficient b:");
  in3 = new JLabel("Enter coefficient c:");
  out1 = new JLabel("Root1:");
result1  = new JLabel("---------------------------------------------");
  out2 = new JLabel("Root2:");
  result2  = new JLabel("---------------------------------------------");
  a = new JTextField(5);
  b = new JTextField(5);
  c = new JTextField(5);
  a.addActionListener(new QListener());
  b.addActionListener(new QListener());
  c.addActionListener(new QListener());
  panel = new JPanel();
  panel.setPreferredSize(new Dimension(WIDTH ,HEIGHT));
  panel.setBackground(Color.blue);
panel.add(in1);
  panel.add(in2);
  panel.add(in3);
  panel.add(a);
  panel.add(b);
  panel.add(c);
  panel.add(out1);
  panel.add(result1);
  panel.add(out2);
  panel.add(result2);
  frame.getContentPane().add(panel);
public void display()
  frame.pack();
  frame.show();
private class QListener implements ActionListener
  public void actionPerformed (ActionEvent event)
   double x,y,z;
   String text1,text2,text3;
   text1 = a.getText();
   text2 = a.getText();
   text3 = a.getText();
   x = Double.parseDouble(text1);
   y = Double.parseDouble(text2);
   z = Double.parseDouble(text3);
   ComplexNumbers A = new ComplexNumbers(x,0.0);
   ComplexNumbers B = new ComplexNumbers(y,0.0);
   ComplexNumbers C = new ComplexNumbers(z,0.0);
   ArrayList myList = new ArrayList();
   Quad Roots = new Quad(A,B,C);
   ArrayList Result = new ArrayList();
   myList.add(0,A);
   myList.add(1,B);
   myList.add(2,C);
   Result = Roots.findRoots(myList);
   result1.setText(ComplexNumbers.toString(Result.get(0)));
   result2.setText(ComplexNumbers.toString(Result.get(1)));
//THE ERROR IS:
QuadGUI.java:86: Wrong number of arguments in method.
   result1.setText(ComplexNumbers.toString(Result.get(0)));
                                          ^
QuadGUI.java:87: Wrong number of arguments in method.
   result2.setText(ComplexNumbers.toString(Result.get(1)));(in the library / JLabel (javax.swing)) public void setText(String text)
how come ?
thanks

Answer 1

well JAVAC don't lie, so the obvious answer is as stated
QuadGUI.java:86: Wrong number of arguments in method.
result1.setText(ComplexNumbers.toString(Result.get(0)));
QuadGUI.java:87: Wrong number of arguments in method.
result2.setText(ComplexNumbers.toString(Result.get(1)))
result2 is a JLabel, setText takes 1 parameter fine.
Result is an ArrayList, method here .get( int ) takes 1 parameter fine - returns an Object
ComplexNumbers.toString( Object )
So I'd look in ComplexNumbers.java or the DOcs for it and see what it expects, probbaly not just 1 Object
and as that's where the ^ is pointing thats a good place to look
if you have problems like this that you get stuck on:
Break up the code! it will instantly show you where your error is
Like this:
Object o = Result.get( 0 );
//System.out.println( o.toString() );
String S = ComplexNumbers.toString( o );
//System.out.println( S );
result1.setText( S );Now the 'wrong number of arguments will point to the use of the ComplexNumbers static Method toString() neh?
And possibly showing the Signature of toString() in ComplexNumbers
would have helped here too......
as in
public static returntype toString( Parameter List)