Assignment-15

Write a program to create a simple calculator using Applet.

Source Code:

import java.applet.*;
import java.awt.*;
import java.awt.event.*;//ActionListener Interface


public class cal extends Applet implements ActionListener
{
 TextField t1;
 int u=0,v=0,w=0;
 Button b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17;
 String str1 ="";
 String str2 ="";
 String str3 ="";
 String str ="";
 String s ="";
 int i=0;
 public void init()
 {
 t1=new TextField(14);
 add(t1);
 b1=new Button("9");
 add(b1);
 b2=new Button("8");
 add(b2);
 b3=new Button("7");
 add(b3);
 b4=new Button("+");
 add(b4);
 b5=new Button("6");
 add(b5);
 b6=new Button("5");
 add(b6);
 b7=new Button("4");
 add(b7);
 b8=new Button("-");
 add(b8);
 b9=new Button("3");
 add(b9);
 b10=new Button("2");
 add(b10);
 b11=new Button("1");
 add(b11);
 b12=new Button("*");
 add(b12);
 b13=new Button("0");
 add(b13);
 b14=new Button(".");
 add(b14);
 b15=new Button("=");
 add(b15);
 b16=new Button("/");
 add(b16);
 b17=new Button("CLEAR");
 add(b17);
 t1.addActionListener(this);
 b1.addActionListener(this);
 b2.addActionListener(this);
 b3.addActionListener(this);
 b4.addActionListener(this);
 b5.addActionListener(this);
 b6.addActionListener(this);
 b7.addActionListener(this);
 b8.addActionListener(this);
 b9.addActionListener(this);
 b10.addActionListener(this);
 b11.addActionListener(this);
 b12.addActionListener(this);
 b13.addActionListener(this);
 b14.addActionListener(this);
 b15.addActionListener(this);
 b16.addActionListener(this);
 b17.addActionListener(this);
 }
 public void actionPerformed(ActionEvent ae)
 {
  if(ae.getActionCommand().equals("9"))
  {
  str3="9";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }

  else if(ae.getActionCommand().equals("8"))
  {
  str3="8";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("7"))
  {
  str3="7";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("6"))
  {
  str3="6";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("5"))
  {
  str3="5";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }



  else if(ae.getActionCommand().equals("4"))
  {
  str3="4";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("3"))
  {
  str3="3";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("2"))
  {
  str3="2";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("1"))
  {
  str3="1";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }



  else if(ae.getActionCommand().equals("0"))
  {
  str3="0";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(ae.getActionCommand().equals("."))
  {
  str3=".";
  str+=str3;
  t1.setText(str);
  v=1;
  if(i==1)
  {
  w=1;
  }
  }
  else if(v==0 && ae.getActionCommand().equals("-"))
  {
  str3="-";
  str+=str3;
  t1.setText(str);
  v=1;
  }
  else if(w==0 && i==1 && ae.getActionCommand().equals("-"))
  {
  str3="-";
  str+=str3;
  t1.setText(str);
  v=1;
  w=1;
  }
  else if(ae.getActionCommand().equals("+") || ae.getActionCommand().equals("-") || ae.getActionCommand().equals("*") || ae.getActionCommand().equals("/"))
  {
   if(ae.getActionCommand().equals("+"))
   {
   s="+";
   }
   else if(ae.getActionCommand().equals("-"))
   { 
   s="-";
   }
   else if(ae.getActionCommand().equals("*"))
   {
   s="*";
   }
   else if(ae.getActionCommand().equals("/"))
   {
   s="/";
   }
  t1.setText("");
  str="";
  i=1;
  }
  if(i==0)
  {
  str1=str;
  }
  if(i==1)
  {
  str2=str;
  } 
 if(ae.getActionCommand().equals("="))
 {
 if(s.equals("+"))
 {
 double x=Double.parseDouble(str1);
 double y=Double.parseDouble(str2);
 double z=x+y;
 t1.setText(String.valueOf(z));
 }
  if(s.equals("-"))
 {
 double x=Double.parseDouble(str1);
 double y=Double.parseDouble(str2);
 double z=x-y;
 t1.setText(String.valueOf(z));
 }
  if(s.equals("*"))
 {
 double x=Double.parseDouble(str1);
 double y=Double.parseDouble(str2);
 double z=x*y;
 t1.setText(String.valueOf(z));
 }
  if(s.equals("/"))
 {
 try{
 double x=Double.parseDouble(str1);
 double y=Double.parseDouble(str2);
 double z=x/y;
 t1.setText(String.valueOf(z));
 }
 catch(ArithmeticException e)
 {
 t1.setText("Error");
 }
 }
 str="";
 }
  if(ae.getActionCommand().equals("CLEAR"))
 {
 t1.setText("");
 str1 ="";
 str2 ="";
 str3 ="";
 str ="";
 s ="";
 i=0;
 v=0;
 w=0;
 }
 }
}