Adding a sqrt button and percentage button to a calculator

**Josie_Taylor** · 03-13-2011, 11:01 PM

Hi i have created this coding so far but am really struggling with adding a percentage button and square root button. i really have no idea and struggling a lot so any help would be much appreciated.

thanks
josie :)

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

public class Calculator2 extends JApplet {
public void init() {
CalculatorPanel calc=new CalculatorPanel();
getContentPane().add(calc);
}
}

class CalculatorPanel extends JPanel implements ActionListener {
JButton
n1,n2,n3,n4,n5,n6,n7,n8,n9,n0,plus,minus,mul,div,d ot,equal,clr,sqrt;
static JTextField result=new JTextField("0",45);
static String lastCommand=null;
JOptionPane p=new JOptionPane();
double preRes=0,secVal=0,res;

private static void assign(String no)
{
if((result.getText()).equals("0"))
result.setText(no);
else if(lastCommand=="=")
{
result.setText(no);
lastCommand=null;
}
else
result.setText(result.getText()+no);
}

public CalculatorPanel() {
setLayout(new BorderLayout());
result.setEditable(false);
result.setSize(300,200);
add(result,BorderLayout.NORTH);
JPanel panel=new JPanel();
panel.setLayout(new GridLayout(5,5));

n7=new JButton("7");
panel.add(n7);
n7.addActionListener(this);
n8=new JButton("8");
panel.add(n8);
n8.addActionListener(this);
n9=new JButton("9");
panel.add(n9);
n9.addActionListener(this);
div=new JButton("/");
panel.add(div);
div.addActionListener(this);

n4=new JButton("4");
panel.add(n4);
n4.addActionListener(this);
n5=new JButton("5");
panel.add(n5);
n5.addActionListener(this);
n6=new JButton("6");
panel.add(n6);
n6.addActionListener(this);
mul=new JButton("*");
panel.add(mul);
mul.addActionListener(this);

n1=new JButton("1");
panel.add(n1);
n1.addActionListener(this);
n2=new JButton("2");
panel.add(n2);
n2.addActionListener(this);
n3=new JButton("3");
panel.add(n3);
n3.addActionListener(this);
minus=new JButton("-");
panel.add(minus);
minus.addActionListener(this);

dot=new JButton(".");
panel.add(dot);
dot.addActionListener(this);
n0=new JButton("0");
panel.add(n0);
n0.addActionListener(this);
equal=new JButton("=");
panel.add(equal);
equal.addActionListener(this);
plus=new JButton("+");
panel.add(plus);
plus.addActionListener(this);
add(panel,BorderLayout.CENTER);

clr=new JButton("c");
panel.add(clr);
clr.addActionListener(this);
sqrt=new JButton("sq");
panel.add(sqrt);
add(panel,BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource()==n1) assign("1");
else if(ae.getSource()==n2) assign("2");
else if(ae.getSource()==n3) assign("3");
else if(ae.getSource()==n4) assign("4");
else if(ae.getSource()==n5) assign("5");
else if(ae.getSource()==n6) assign("6");
else if(ae.getSource()==n7) assign("7");
else if(ae.getSource()==n8) assign("8");
else if(ae.getSource()==n9) assign("9");
else if(ae.getSource()==n0) assign("0");
else if(ae.getSource()==dot)
{
if(((result.getText()).indexOf("."))==-1)
result.setText(result.getText()+".");
}

else if(ae.getSource()==minus)
{
preRes=Double.parseDouble(result.getText());
lastCommand="-";
result.setText("");
}
else if(ae.getSource()==clr)
{
preRes=Double.parseDouble(result.getText());
lastCommand="c";
result.setText("");
}
else if(ae.getSource()==div)
{
preRes=Double.parseDouble(result.getText());
lastCommand="/";
result.setText("");
}
else if(ae.getSource()==div)
{
preRes=Double.parseDouble(result.getText());
lastCommand="sq";
result.setText("");
}
else if(ae.getSource()==equal)
{
secVal=Double.parseDouble(result.getText());
if (lastCommand.equals("/"))
res=preRes/secVal;
else if(lastCommand.equals("*"))
res=preRes*secVal;
else if(lastCommand.equals("-"))
res=preRes-secVal;
else if(lastCommand.equals("+"))
res=preRes+secVal;
result.setText(" "+res);
lastCommand="=";
}
else if(ae.getSource()==mul)
{
preRes=Double.parseDouble(result.getText());
lastCommand="*";
result.setText("");
}
else if(ae.getSource()==plus)
{
preRes=Double.parseDouble(result.getText());
lastCommand="+";
result.setText("");
}

}
}

**Iron Lion** · 03-13-2011, 11:06 PM

Math.sqrt() should solve one of your problems. As for the percentage button, 80 * 20% on a calculator is really just syntactic sugar for 80 * 0.2, so all you need to do is convert it to the appropriate multiplication operation.

**Josie_Taylor** · 03-14-2011, 12:09 AM

i have now changed my code to this but i can see its all wrong but feel with a couple of tweaks it will work. this is still in regards to the percentage and sqrt buttons
many thanks again

Java Code:

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

public class Calculator2 extends JApplet {
 public void init() {
    CalculatorPanel calc=new CalculatorPanel();
    getContentPane().add(calc);
    }
 }

 class CalculatorPanel extends JPanel implements ActionListener {
    JButton 
n1,n2,n3,n4,n5,n6,n7,n8,n9,n0,plus,minus,mul,div,dot,equal,clr,pcent,sqrt;
    static JTextField result=new JTextField("0",45);
    static String lastCommand=null;
    JOptionPane p=new JOptionPane();
    double preRes=0,secVal=0,res;

    private static void assign(String no)
      {
       if((result.getText()).equals("0"))
          result.setText(no);
        else if(lastCommand=="=")
         {
          result.setText(no);
          lastCommand=null;
         }
        else
          result.setText(result.getText()+no);
       }

    public CalculatorPanel() {
       setLayout(new BorderLayout());
       result.setEditable(false);
       result.setSize(300,200);
       add(result,BorderLayout.NORTH);
       JPanel panel=new JPanel();
       panel.setLayout(new GridLayout(5,5));

       n7=new JButton("7");
       panel.add(n7);
       n7.addActionListener(this);
       n8=new JButton("8");
       panel.add(n8);
       n8.addActionListener(this);
       n9=new JButton("9");
       panel.add(n9);
       n9.addActionListener(this);
       div=new JButton("/");
       panel.add(div);
       div.addActionListener(this);

       n4=new JButton("4");
       panel.add(n4);
       n4.addActionListener(this);
       n5=new JButton("5");
       panel.add(n5);
       n5.addActionListener(this);
       n6=new JButton("6");
       panel.add(n6);
       n6.addActionListener(this);
       mul=new JButton("*");
       panel.add(mul);
       mul.addActionListener(this);

       n1=new JButton("1");
       panel.add(n1);
       n1.addActionListener(this);
       n2=new JButton("2");
       panel.add(n2);
       n2.addActionListener(this);
       n3=new JButton("3");
       panel.add(n3);
       n3.addActionListener(this);
       minus=new JButton("-");
       panel.add(minus);
       minus.addActionListener(this);

       dot=new JButton(".");
       panel.add(dot);
       dot.addActionListener(this);
       n0=new JButton("0");
       panel.add(n0);
       n0.addActionListener(this);
       equal=new JButton("=");
       panel.add(equal);
       equal.addActionListener(this);
       plus=new JButton("+");
       panel.add(plus);
       plus.addActionListener(this);
       add(panel,BorderLayout.CENTER);
       
       clr=new JButton("c");
       panel.add(clr);
       clr.addActionListener(this);
       pcent=new JButton("%");
       panel.add(pcent);
       sqrt=new JButton("sq");
       panel.add(sqrt);
       add(panel,BorderLayout.CENTER);
       }
    public void actionPerformed(ActionEvent ae)
       {
    if(ae.getSource()==n1) assign("1");
    else if(ae.getSource()==n2) assign("2");
    else if(ae.getSource()==n3) assign("3");
    else if(ae.getSource()==n4) assign("4");
    else if(ae.getSource()==n5) assign("5");
    else if(ae.getSource()==n6) assign("6");
    else if(ae.getSource()==n7) assign("7");
    else if(ae.getSource()==n8) assign("8");
    else if(ae.getSource()==n9) assign("9");
    else if(ae.getSource()==n0) assign("0");
    else if(ae.getSource()==dot)
          {
           if(((result.getText()).indexOf("."))==-1)
              result.setText(result.getText()+".");
         }
    
    else if(ae.getSource()==minus)
           {
           preRes=Double.parseDouble(result.getText());
           lastCommand="-";
           result.setText("");
           }
    else if(ae.getSource()==clr)
    {
    preRes=Double.parseDouble(result.getText());
    lastCommand="c";
    result.setText("");
    }
    else if(ae.getSource()==div)
           {
    	   preRes=Double.parseDouble(result.getText());
           lastCommand="/";
           result.setText("");
           }
        else if(ae.getSource()==equal)
           {
           secVal=Double.parseDouble(result.getText());
           if (lastCommand.equals("/"))
   				res=preRes/secVal;
           else if(lastCommand.equals("*"))
                res=preRes*secVal;
           else if(lastCommand.equals("-"))
                res=preRes-secVal;
           else if(lastCommand.equals("+"))
        	   res=preRes+secVal;
           else if(lastCommand.equals("sq"))
        	   res=Math.sqrt(preRes);
           	   result.setText(" "+res);
        	   lastCommand="=";
        	   }
    else if(ae.getSource()==pcent)
    {
    secVal=Double.parseDouble(result.getText());
    if (lastCommand.equals("/"))
			res=preRes/(secVal/100);
    else if(lastCommand.equals("*"))
         res=preRes*(secVal/100);
    else if(lastCommand.equals("-"))
         res=preRes-(secVal/100);
    else if(lastCommand.equals("+"))
 	   res=preRes+(secVal/100);
    	   result.setText(" "+res);
 	   lastCommand="%";
 	   }
    else if(ae.getSource()==mul)
           {
            preRes=Double.parseDouble(result.getText());
            lastCommand="*";
            result.setText("");
            }
    else if(ae.getSource()==plus)
            {
            preRes=Double.parseDouble(result.getText());
            lastCommand="+";
            result.setText("");
            }
       }

 }

**ozzyman** · 03-14-2011, 01:03 AM

So the problem is not calculating the square-root but rather adding a JButton and labelling it SQRT? Could you please clarify

**Fubarable** · 03-14-2011, 01:16 AM

Agrees with ozzy -- what specifically is your current question?

Also, I've edited your last post and have added code tags to your code to help it keep its formatting and be readable, since your goal is to get as many people to read your post and understand your code as possible, right?

To do this yourself next time, highlight your pasted code (please be sure that it is already formatted when you paste it into the forum; the code tags don't magically format unformatted code) and then press the code button, and your code will have tags.

Another way to do this is to manually place the tags into your code by placing the tag [code] above your pasted code and the tag [/code] below your pasted code like so:

Java Code:

[cod&#101;]
  // your code goes here
  // notice how the top and bottom tags are different
[/cod&#101;]

Thread: Adding a sqrt button and percentage button to a calculator

LinkBack

Thread Tools

Search Thread

Display

Adding a sqrt button and percentage button to a calculator

Similar Threads

Does any one know how to write this e^sqrt(lognloglog(n)) ,where n is biginteger

adding flash file to a button!

Adding "Choose File" button to applet

Calculator Online(Without Button)

Adding EXIT button on MIDlet form

Bookmarks

Bookmarks

Posting Permissions

License4J 4.0

Pastèque Server 0.3

Nuiton-I18n 2.5.1

Xowa 0.5.2

DEMUX Framework 0.1

GSLB.me Dynamic DNS Client 0.1

ZedLog 0.2 Beta

Dragon parser generator 1.3.9

Data Crow 3.10

Jailer 4.0.15.rc

Class random

Movement not working...

Java Audio and Timer Functions,...

VMware VFabric server not running

Hmm... Something is not right here!

Severly messed up my program!!!

JPanel widths/heights

CS106a assignment 3 help

I get this enormous error...

freetype in java library