Hi..everyone...I have created this simple java calculator for addition and subtraction.
Can anyone help me get the result till 40 decimal places when necessary...Right now it works till 15-16 decimal places but how do i change that to 40....
Thanks....


import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.Object;


public class Calculator extends JFrame implements ActionListener

{
public static final int WIDTH= 400;
public static final int HEIGHT= 175;

private JTextField inputField;
private JTextField inputField1;
private JTextField outputField;
private double sum=0;
private String sumString;
private JLabel label1,label2, label3, label4;

public static void main (String [] args)
{

Calculator guiCalculator = new Calculator();
guiCalculator.setVisible(true);


}
public Calculator()
{
setTitle ("Java Calculator");
setSize(WIDTH, HEIGHT);
Container contentPane = getContentPane();
contentPane.setLayout (new GridLayout());

JPanel textArea = new JPanel();
textArea.setBackground(Color.green);
textArea.setLayout(new FlowLayout());

label1 = new JLabel( "Enter 1st Number Here" );
textArea.add( label1 );

inputField = new JTextField("", 15);
inputField.setBackground(Color.white);
textArea.add(inputField);

label2 = new JLabel( "Enter 2nd Number Here" );
textArea.add( label2 );

inputField1= new JTextField("",15);
inputField1.setBackground(Color.WHITE);
textArea.add(inputField1);

JPanel buttonPanel = new JPanel();
buttonPanel.setBackground(Color.GRAY);
buttonPanel.setLayout(new GridLayout());

JButton addButton = new JButton("Add");
addButton.addActionListener(this);
buttonPanel.add(addButton);


JButton resetButton = new JButton("Reset");
resetButton.addActionListener(this);
buttonPanel.add(resetButton);


JButton subtractButton = new JButton("Subtract");
subtractButton.addActionListener(this);
buttonPanel.add(subtractButton);


Panel b = new Panel();
b.setLayout(new GridLayout(1,3));
b.add(addButton);
b.add(subtractButton);
b.add(resetButton);
textArea.add(b);
contentPane.add(textArea, BorderLayout.CENTER);
outputField = new JTextField("Result", 30);
outputField.setBackground(Color.WHITE);
textArea.add(outputField);

label3 = new JLabel( "Java Calculator");

textArea.add( label3 );
}

public void actionPerformed (ActionEvent e)
{
try
{
if(e.getActionCommand().equals("Add"))
{
sum = stringToDouble(inputField.getText()) + stringToDouble(inputField1.getText());
String sumString = Double.toString(sum);
outputField.setText(sumString);
}
if(e.getActionCommand().equals("Subtract"))
{
sum = stringToDouble(inputField.getText()) - stringToDouble(inputField1.getText());

String sumString = Double.toString(sum);
outputField.setText(sumString);
}
if (e.getActionCommand().equals("Reset"))
{
sum = 0;
inputField.setText("0.0");
inputField1.setText("0.0");
outputField.setText("0.0");
}
}

catch (Exception exception)
{
sum = 0;
inputField.setText("Enter Only Numbers");
inputField1.setText("Enter Only Numbers");
outputField.setText("0.0");
}
}


private static double stringToDouble(String stringObject)
{
return Double.parseDouble(stringObject.trim());

}
}

does double variable hold a number with 40 decimals ???........... if it does not u can parse the string into 2 or more sub strings and add separately ....... and again concatenate the answer into one string.