Textfield Problem

[Beth Laguardia]

Hi everyone, I am trying to make a simple calculator.. everything works but when i tried to input more than 11 numbers in my textfield then press the operators the numbers in the ext field CHAnGES!! I have no idea why!

Can please anybody healp me? Thanks

Sample input: 123456789111 Then if I press one of the operators it will change to 2147483647..

   package ProjectFinals;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
 
public class Calculator {

JFrame frame;
JButton bckSpce,button0,button1,button2,button3,button4,button5,button6,button7,button8,button9,ekwals,tuldok;
JButton plus,minus,times,dibide,clear;
JTextField field;
    String b0="0",b1="1",b2="2",b3="3",b4="4",b5="5",b6="6",b7="7",b8="8",b9="9",pt = ".", strNum,input;
static int ctr1=0,ptTemp=0;
String preOpe=null,tempOperator=null,strTotal=null;
double total=0;

public static void main(String[] args) {
    Calculator newCal = new Calculator(); 
   }

public Calculator()
{
frame = new JFrame("My Calculator");
frame.setLayout(null);

        field = new JTextField();
        frame.getContentPane().add(field);
        field.setBounds(5,10,275,40);
        field.setText(Integer.toString(0));
        
        clear = new JButton("Clear");
        frame.getContentPane().add(clear);
        clear.setBounds(45,80,100,40);
        clear.addActionListener(new Calculate());
        
        bckSpce = new JButton("Backspace");
        frame.getContentPane().add(bckSpce);
        bckSpce.setBounds(155,80,100,40);
        bckSpce.addActionListener(new Calculate());
      
        
        button7 = new JButton("7");
        frame.getContentPane().add(button7);
        button7.setBounds(45,130,45,30);
        button7.addActionListener(new Calculate());
        
        
        button8 = new JButton("8");
        frame.getContentPane().add(button8);
        button8.setBounds(100,130,45,30);
        button8.addActionListener(new Calculate());
        
        button9 = new JButton("9");
        frame.getContentPane().add(button9);
        button9.setBounds(155,130,45,30);
        button9.addActionListener(new Calculate());
        
        plus = new JButton("+");
        frame.getContentPane().add(plus);
        plus.setBounds(210,130,45,30);
        plus.addActionListener(new Calculate());
        
        button4 = new JButton("4");
        frame.getContentPane().add(button4);
        button4.setBounds(45,165,45,30);
        button4.addActionListener(new Calculate());
        
        button5 = new JButton("5");
        frame.getContentPane().add(button5);
        button5.setBounds(100,165,45,30);
        button5.addActionListener(new Calculate());
        
        button6 = new JButton("6");
        frame.getContentPane().add(button6);
        button6.setBounds(155,165,45,30);
        button6.addActionListener(new Calculate());
        
        minus = new JButton("-");
        frame.getContentPane().add(minus);
        minus.setBounds(210,165,45,30);
        minus.addActionListener(new Calculate());
        
        button1 = new JButton("1");
        frame.getContentPane().add(button1);
        button1.setBounds(45,200,45,30);
        button1.addActionListener(new Calculate());
        
        button2 = new JButton("2");
        frame.getContentPane().add(button2);
        button2.setBounds(100,200,45,30);
        button2.addActionListener(new Calculate());
        
        button3 = new JButton("3");
        frame.getContentPane().add(button3);
        button3.setBounds(155,200,45,30);
        button3.addActionListener(new Calculate());
        
        times = new JButton("*");
        frame.getContentPane().add(times);
        times.setBounds(210,200,45,30);
        times.addActionListener(new Calculate());
        
        button0 = new JButton("0");
        frame.getContentPane().add(button0);
        button0.setBounds(45,235,45,30);
        button0.addActionListener(new Calculate());
        
        tuldok = new JButton(".");
        frame.getContentPane().add(tuldok);
        tuldok.setBounds(100,235,45,30);
        tuldok.addActionListener(new Calculate());
        
        ekwals = new JButton("=");
        frame.getContentPane().add(ekwals);
        ekwals.setBounds(155,235,45,30);
        ekwals.addActionListener(new Calculate());
        
        dibide = new JButton("/");
        frame.getContentPane().add(dibide);
        dibide.setBounds(210,235,45,30);
        dibide.addActionListener(new Calculate());  
        
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,350);
frame.setVisible(true);
  

}

public class Calculate implements ActionListener
{
CheckOperators newOpe = new CheckOperators();
  public void actionPerformed(ActionEvent e)
{
  if((e.getSource() == button1) || (e.getSource()== button2) ||
                     (e.getSource()==button3) || (e.getSource()== button4) ||
                     (e.getSource()==button5) || (e.getSource()==button6) ||
                     (e.getSource()==button7) || (e.getSource()==button8) ||
                     (e.getSource()==button9))
  {
  if(ctr1>0)
  {
  input=field.getText();
  if(e.getSource()==button0)
field.setText(input + b0);
  if(e.getSource()==button1)
    field.setText(input + b1);
  if(e.getSource()==button2)
    field.setText(input + b2);
  if(e.getSource()==button3)
    field.setText(input + b3);
  if(e.getSource()==button4)
    field.setText(input + b4);
  if(e.getSource()==button5)
    field.setText(input + b5);
  if(e.getSource()==button6)
    field.setText(input + b6);
  if(e.getSource()==button7)
    field.setText(input + b7);
  if(e.getSource()==button8)
    field.setText(input + b8);
  if(e.getSource()==button9)
    field.setText(input + b9);
 
  }
  else
  {
  if(e.getSource()==button1)
                    field.setText(b1);
  if(e.getSource()==button2)
     field.setText(b2);
  if(e.getSource()==button3)
     field.setText(b3);
  if(e.getSource()==button3)
     field.setText(b3);
  if(e.getSource()==button4)
     field.setText(b4);
  if(e.getSource()==button5)
     field.setText(b5);
  if(e.getSource()==button6)
     field.setText(b6);
  if(e.getSource()==button7)
     field.setText(b7);
  if(e.getSource()==button8)
     field.setText(b8);
  if(e.getSource()==button9)
     field.setText(b9);
  }
  
  ctr1++;
  }  
  if(e.getSource()==bckSpce)
  {   
  char strTemp;
              strNum = field.getText();
              int length = strNum.length()-2;
              if(length < 0)
              field.setText("");
              else if (length==0)
              {
              strTemp = strNum.charAt(0);
                  strNum = Character.toString(strTemp);
                  field.setText(strNum);
              }
              
              else
              {
              String strTemp1=null,strTemp2;
              for(int i = 0; i<=length; i++)
              {
              if(i==0)
                {
              strTemp = strNum.charAt(i);
              field.setText(Character.toString(strTemp));
              strTemp1 = field.getText();
                }
              else
              {
                          strTemp=strNum.charAt(i);
                          strTemp2 = Character.toString(strTemp);
                          strTemp1 = strTemp1 + strTemp2;
                          field.setText(strTemp1);  
              } 
              }
              }
  }
  
  if (e.getSource() == tuldok)
  {
  if(ctr1>0)
  {
  input=field.getText();
  field.setText(input + pt);
  }
  else
  {
  field.setText(pt);
  }
  ctr1++;
  ptTemp++;
}// button2
  
  
  if ((e.getSource() == minus) || (e.getSource() == plus) ||
                      (e.getSource() == dibide) || (e.getSource() == times))
  {
  
  if(e.getSource() == plus)
  tempOperator = "plus";
  else if (e.getSource()== minus)
  tempOperator ="minus";
  else if (e.getSource()== dibide)
      tempOperator = "dibide";
  else
  tempOperator = "times";
  
  strNum = field.getText();
  strNum = newOpe.getOperators(strNum,preOpe,strTotal);
  field.setText(strNum);
  strTotal = strNum;
  preOpe = tempOperator;
  ctr1=0;
  }
  
  if (e.getSource() == ekwals)
  {
  strNum = field.getText();
  strNum = newOpe.getOperators(strNum,preOpe,strTotal);
  field.setText(strNum);
  strTotal = null;
  preOpe = null;
  ctr1=0;
  ptTemp=0;
  }
  
  if (e.getSource() == clear)
  {
  strTotal = null;
  preOpe = null;
  field.setText(" ");
  strTotal = null;
  preOpe = null;
  ctr1=0;
  ptTemp=0;
  }
 
}
  
  public class CheckOperators
  {
  public String getOperators(String strNum, String preOpe, String strTotal)
     {
          try {
    double temp = Double.parseDouble(strNum);
    if (preOpe == null)
    {
               total = temp;
    }
    else if(preOpe.equals("plus"))
    {
    total = Double.parseDouble(strTotal);       
    total = total + temp;   
    }
    else if(preOpe.equals("minus"))
    {
    total = Double.parseDouble(strTotal);           
    total = total - temp;
    }
    else if(preOpe.equals("times"))
    {
 
     total = Double.parseDouble(strTotal);       
     total = total * temp;
    }
    
    else
    {
     total = Double.parseDouble(strTotal);           
    total = total / temp;
    }
    
     if(ptTemp==0)
     strNum = Integer.toString((int) total);
     else     
     strNum = Double.toString(total);
    
    return strNum;
     } // end of try
    catch(NumberFormatException e)
    {
    strNum = "Input Error";
    return strNum;
    }
  
}
  }

} //end actionListener

    
}// end Calculator
 
 

[ September 19, 2008: Message edited by: Rob Prime ]

[Rob Spoor]

2147483647 is Integer.MAX_VALUE; perhaps you should think about using long or even BigInteger for your results.

[Brian Cole]

Originally posted by Beth Laguardia:
Hi everyone, I am trying to make a simple calculator.. everything works but when i tried to input more than 11 numbers in my textfield then press the operators the numbers in the ext field CHAnGES!! I have no idea why!

I haven't actually run your code, but I would guess that it's the
normal limitations of the double type that java (and many
other languages) uses. There are some values that it just can't
represent, and 123456789111 is one of them. If you don't like
this, you could try using BigDecimal instead.

While I'm here, allow me ask a couple things about your code:

1) Why bother to use String variables b0, b1, etc? (I would just use
the String literals "0", "1", etc. but if you really want to use those
variables, perhaps you should declare them to be static final.)

2) Is there a reason you're doing setLayout(null) and manually
calling setBounds() on everything?

[Beth Laguardia]

Originally posted by Brian Cole:


I haven't actually run your code, but I would guess that it's the
normal limitations of the double type that java (and many
other languages) uses. There are some values that it just can't
represent, and 123456789111 is one of them. If you don't like
this, you could try using BigDecimal instead.

While I'm here, allow me ask a couple things about your code:

1) Why bother to use String variables b0, b1, etc? (I would just use
the String literals "0", "1", etc. but if you really want to use those
variables, perhaps you should declare them to be static final.)

2) Is there a reason you're doing setLayout(null) and manually
calling setBounds() on everything?

Thank you for explanation. I do not know yet how use BigDecimal but will check on it.

With using the string literals, I will denitely change it string literals. Thanks for that input.

I have no idea yet what is static final, but i have check on it also.

I have set the frame to null because if i remove if all my buttons will be gone. Is there a better way to do this?

Thank you all or the response.. )

[pete stein]

Originally posted by Beth Laguardia:
I have set the frame to null because if i remove if all my buttons will be gone. Is there a better way to do this?

Most definitely. Please have a look at the Sun tutorial on the AWT layout managers. If you let the layout managers do the hard work for you, laying your components, your program will be much more flexible and maintainable.