Coding Java Calculator….

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

/*
* Calculator.java
*
* Created on Apr 29, 2010, 6:15:35 PM
*/

/**
*
* @author DEV
*/
public class Calculator extends javax.swing.JFrame {
int r1;
int r2;
String option;
int result;
/** Creates new form Calculator */
public Calculator() {
initComponents();
}

/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings(“unchecked”)
// <editor-fold defaultstate=”collapsed” desc=”Generated Code”>
private void initComponents() {

jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jButton4 = new javax.swing.JButton();
jButton5 = new javax.swing.JButton();
jButton6 = new javax.swing.JButton();
jButton7 = new javax.swing.JButton();
jButton8 = new javax.swing.JButton();
jButton9 = new javax.swing.JButton();
jButton10 = new javax.swing.JButton();
jButton11 = new javax.swing.JButton();
jButton12 = new javax.swing.JButton();
jButton13 = new javax.swing.JButton();
jButton14 = new javax.swing.JButton();
jButton15 = new javax.swing.JButton();
CalcTF = new javax.swing.JTextField();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

jButton1.setText(“1″);
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton2.setText(“2″);
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton3.setText(“3″);
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton4.setText(“4″);
jButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton5.setText(“5″);
jButton5.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton6.setText(“6″);
jButton6.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton7.setText(“7″);
jButton7.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton8.setText(“8″);
jButton8.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton9.setText(“9″);
jButton9.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton10.setText(“0″);
jButton10.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
DigitPressed(evt);
}
});

jButton11.setText(“=”);
jButton11.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton11ActionPerformed(evt);
}
});

jButton12.setText(“+”);
jButton12.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton12ActionPerformed(evt);
}
});

jButton13.setText(“-”);
jButton13.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton13ActionPerformed(evt);
}
});

jButton14.setText(“/”);
jButton14.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton14ActionPerformed(evt);
}
});

jButton15.setText(“*”);
jButton15.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton15ActionPerformed(evt);
}
});

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(97, 97, 97)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(CalcTF, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 184, Short.MAX_VALUE)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton5))
.addGroup(layout.createSequentialGroup()
.addComponent(jButton9)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton8)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton7)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton12))
.addGroup(layout.createSequentialGroup()
.addComponent(jButton6)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton13, 0, 0, Short.MAX_VALUE))))
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(jButton10, javax.swing.GroupLayout.Alignment.LEADING, 0, 0, Short.MAX_VALUE)
.addComponent(jButton1, javax.swing.GroupLayout.Alignment.LEADING))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton3))
.addComponent(jButton11, javax.swing.GroupLayout.PREFERRED_SIZE, 88, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton14, javax.swing.GroupLayout.DEFAULT_SIZE, 43, Short.MAX_VALUE)
.addComponent(jButton15, javax.swing.GroupLayout.DEFAULT_SIZE, 43, Short.MAX_VALUE))))
.addGap(126, 126, 126))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(69, Short.MAX_VALUE)
.addComponent(CalcTF, javax.swing.GroupLayout.PREFERRED_SIZE, 32, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton7)
.addComponent(jButton8)
.addComponent(jButton9)
.addComponent(jButton12))
.addGap(6, 6, 6)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton4)
.addComponent(jButton5)
.addComponent(jButton6)
.addComponent(jButton13))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2)
.addComponent(jButton3)
.addComponent(jButton15))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton10)
.addComponent(jButton11)
.addComponent(jButton14))
.addGap(78, 78, 7)
);

pack();
}// </editor-fold>

private void DigitPressed(java.awt.event.ActionEvent evt) {
String txt =evt.getActionCommand();
String calcval =CalcTF.getText();
if (txt.equals(“0″))
CalcTF.setText(calcval +”0″);
if (txt.equals(“1″))
CalcTF.setText(calcval +”1″);
if (txt.equals(“2″))
CalcTF.setText(calcval +”2″);
if (txt.equals(“3″))
CalcTF.setText(calcval +”3″);
if (txt.equals(“4″))
CalcTF.setText(calcval +”4″);
if (txt.equals(“5″))
CalcTF.setText(calcval +”5″);
if (txt.equals(“6″))
CalcTF.setText(calcval +”69″);
if (txt.equals(“7″))
CalcTF.setText(calcval +”7″);
if (txt.equals(“8″))
CalcTF.setText(calcval +”8″);
if (txt.equals(“9″))
CalcTF.setText(calcval +”9″);

}

private void jButton12ActionPerformed(java.awt.event.ActionEvent evt) {
r1=Integer.parseInt(CalcTF.getText());
option = jButton12.getText();
CalcTF.setText(“”);
}

private void jButton11ActionPerformed(java.awt.event.ActionEvent evt) {
r2=Integer.parseInt(CalcTF.getText());
if (option.equals(“+”))
result=r1+r2;
if (option.equals(“-”))
result=r1-r2;
if (option.equals(“*”))
result=r1*r2;
if (option.equals(“/”))
result=r1/r2;
CalcTF.setText(result+” “);
}

private void jButton13ActionPerformed(java.awt.event.ActionEvent evt) {
r1=Integer.parseInt(CalcTF.getText());
option = jButton13.getText();
CalcTF.setText(“”);
}

private void jButton15ActionPerformed(java.awt.event.ActionEvent evt) {
r1=Integer.parseInt(CalcTF.getText());
option = jButton15.getText();
CalcTF.setText(“”);
}

private void jButton14ActionPerformed(java.awt.event.ActionEvent evt) {
r1=Integer.parseInt(CalcTF.getText());
option = jButton14.getText();
CalcTF.setText(“”);
}

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Calculator().setVisible(true);
}
});
}

// Variables declaration – do not modify
private javax.swing.JTextField CalcTF;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton10;
private javax.swing.JButton jButton11;
private javax.swing.JButton jButton12;
private javax.swing.JButton jButton13;
private javax.swing.JButton jButton14;
private javax.swing.JButton jButton15;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JButton jButton5;
private javax.swing.JButton jButton6;
private javax.swing.JButton jButton7;
private javax.swing.JButton jButton8;
private javax.swing.JButton jButton9;
// End of variables declaration

}