Calculator using java programming

1. Open text editor and copy  following code and paste and save

file name : calculator.java

 
//<applet code="calculator.class" height="318" name="calculator" viewastext="" width="201"><param foreground="" value="FFFFFF" /><param name="background" value="008080" /><param from="" his="" host.="" html="" name="label" passed="" string="" the="" was="" /></applet>

import java.awt.*;
import java.awt.event.*;

public class calculator extends java.applet.Applet implements ActionListener {
 TextField txtTotal = new TextField("");
    Button button[] = new Button[10];
 Button divide = new Button("/");
 Button mult = new Button("*");
 Button plus = new Button ("+");
 Button minus = new Button("-");
 Button isequalto = new Button("=");
 Button clear = new Button("CA");
 double num ,numtemp ;
 int counter;
 String strnum = "",strnumtemp = "" ;
 String op = "";

 public void operation() {
  counter ++;
   if (counter == 1) {
    numtemp = num;
    strnum = "";
    num = 0;
   }else{
    if (op == "+") numtemp += num;
    else if (op == "-") numtemp -= num;
    else if (op == "*") numtemp = numtemp * num;
    else if (op == "/") numtemp = numtemp / num;
    strnumtemp = Double.toString(numtemp);
    txtTotal.setText(strnumtemp);
    strnum = "";
    num = 0;
   }
 }

 public void init() {
  setLayout(null);

  plus.setBackground(Color.blue);
  plus.setForeground(Color.white);
     minus.setBackground(Color.blue);
  minus.setForeground(Color.white);
     divide.setBackground(Color.blue);
  divide.setForeground(Color.white);
  isequalto.setBackground(Color.blue);
  isequalto.setForeground(Color.white);
  mult.setBackground(Color.blue);
  mult.setForeground(Color.white);
  clear.setBackground(Color.blue);
  clear.setForeground(Color.red);

  for(int i = 0;i <= 9; i ++) {
   button[i] = new Button(String.valueOf(i));
   button[i].setBackground(Color.orange);
   button[i].setForeground(Color.blue);
  }

  button[1].setBounds(0,53,67,53);
  button[2].setBounds(67,53,67,53);
  button[3].setBounds(134,53,67,53);
  button[4].setBounds(0,106,67,53);
  button[5].setBounds(67,106,67,53);
  button[6].setBounds(134,106,67,53);
  button[7].setBounds(0,159,67,53);
  button[8].setBounds(67,159,67,53);
  button[9].setBounds(134,159,67,53);

  for (int i = 1;i <= 9; i ++) {
   add(button[i]);
  }

  txtTotal.setBounds(0,0,200,53);
  add(txtTotal);
  plus.setBounds(0,212,67,53);
  add(plus);
  button[0].setBounds(67,212,67,53);
  add(button[0]);
  minus.setBounds(134,212,67,53);
  add(minus);
  divide.setBounds(134,264,67,53);
  add(divide);
  isequalto.setBounds(67,264,67,53);
  add(isequalto);
  mult.setBounds(0,264,67,53);
  add(mult);
  add(clear);
 }

 public void start() {
  for(int i = 0;i <= 9; i ++) {
   button[i].addActionListener(this);
  }
  plus.addActionListener(this);
  minus.addActionListener(this);
  divide.addActionListener(this);
  mult.addActionListener(this);
  isequalto.addActionListener(this);
  clear.addActionListener(this);
 }

 public void stop() {
  for(int i = 0;i <= 9; i ++) {
   button[i].addActionListener(null);
  }
  plus.addActionListener(null);
  minus.addActionListener(null);
  divide.addActionListener(null);
  mult.addActionListener(null);
  isequalto.addActionListener(null);
  clear.addActionListener(null);
 }

 public void actionPerformed(ActionEvent e) {
  for(int i = 0;i <= 9; i++) {
   if (e.getSource() == button[i]) {
      play(getCodeBase(),i + ".au");
      strnum += Integer.toString(i);
      txtTotal.setText(strnum);
      num = Double.valueOf(strnum).doubleValue();
   }
  }

        if (e.getSource() == plus) {
   operation();
   op = "+";
  }

  if (e.getSource() == minus) {
   operation();
   op = "-";
  }

  if (e.getSource() == divide) {
   operation();
   op = "/";
  }

  if (e.getSource() == mult) {
   operation();
   op = "*";
  }

  if (e.getSource() == isequalto) {
   if (op == "+") numtemp += num;
   else if (op == "-") numtemp -= num;
   else if (op == "*") numtemp = numtemp * num;
   else if (op == "/") numtemp = numtemp / num;

   strnumtemp = Double.toString(numtemp);
   txtTotal.setText(strnumtemp);
   strnumtemp = "";
   numtemp = 0;
   strnum = "";
   num = 0;
   counter = 0;
  }

  if (e.getSource() == clear) {
   txtTotal.setText("0");
   strnumtemp = "";
   numtemp = 0;
   strnum = "";
   num = 0;
   counter = 0;
  }
 }
}
    

2.Open Command Prompt

3.Output