how to subtract decimal????

[raymond yadao]

hi guys!!!
i had a program that subtract two double variable.here's my code:

import java.awt.*;
import java.awt.event.*;
 
public class Try
{
    public static void main(String argv[])
    {
        Frame fr = new Frame();
        fr.pack();
        fr.setVisible(true);
        
        Panel panel = new Panel();
        
        final TextField tf1 = new TextField(15);
        final TextField tf2 = new TextField(15);
        
        final Button subtract = new Button("Minus");
        Button clear = new Button("Clear");
        subtract.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                if (e.getSource() == subtract)
                {
                    double a = new Double(tf1.getText()).doubleValue();
                    double b = new Double(tf2.getText()).doubleValue();
                    
                    System.out.println(a-b);
                }
            }
        });
        
        panel.add(tf1);
        panel.add(tf2);
        panel.add(subtract);
        panel.add(clear);
        
        fr.add(panel);
    }//End of main
}

OUTPUT:
TF1 = 50.56
TF2 = 25
DIFFERENCE = 25.560000000000002

how would i make it so that it will only return 25.26???
thanks in advance!!!
[ May 27, 2002: Message edited by: Dirk Schreckmann ]

[Dirk Schreckmann]

Do you mean 25.56?
Take a peek at the DecimalFormat class.

[Ilja Preuss]

Take a look at https://coderanch.com/t/391646/java/java/bug-or

[Dirk Schreckmann]

Isn't it nice when someone actually reads the question asked? I had it in my mind that you were asking how to display. Follow Ilja's lead on learning about what is going on with the numbers and then when you'd like to display them, take a look at the aforementioned class.
Good Luck.

[Pradyumna Hari]

Hi I modified the code to reflect what you want.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.NumberFormat;
import java.text.DecimalFormat;
 
public class Try
{
    public static void main(String argv[])
    {
        JFrame fr = new JFrame();
        fr.pack();
        fr.setVisible(true);
        
        Panel panel = new Panel();
        
        final TextField tf1 = new TextField(15);
        final TextField tf2 = new TextField(15);
        final TextField tf3 = new TextField(15);
        JLabel lf1 = new JLabel(" - ");
        JLabel lf2 = new JLabel(" = ");
        
        final Button subtract = new Button("Minus");
        Button clear = new Button("Clear");
        clear.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                tf1.setText("");
                tf2.setText("");
                tf3.setText("");
            }
        });
        subtract.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                if (e.getSource() == subtract)
                {
                    double a = new Double(tf1.getText()).doubleValue();
                    double b = new Double(tf2.getText()).doubleValue();
                    NumberFormat nf = NumberFormat.getInstance();
                    ((DecimalFormat)nf).applyPattern("##00.00;(##00.00)");
                    ((DecimalFormat)nf).toPattern();
                    
                    System.out.println(nf.format(a-b));
                    tf3.setText(nf.format(a-b));
                }
            }
        });
        
        panel.add(tf1);
        panel.add(lf1);
        panel.add(tf2);
        panel.add(lf2);
        panel.add(tf3);
        panel.add(subtract);
        panel.add(clear);
        
        fr.getContentPane().add(panel);
        fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
    }//End of main
}

[ May 27, 2002: Message edited by: Dirk Schreckmann ]