Java Tutorial For Beginners: Part 4.

Problem: Java Program To Implement Calculator Using Applet.

import java.awt.*;

import java.awt.event.*;

import java.applet.*;

public class Calculator extends Applet implements ActionListener {

private static final long serialVersionUID = 1L;

String msg=" ";

int v1,v2,result;

TextField t1;

Button b[]=new Button[10];

Button add,sub,mul,div,clear,mod,EQ;

char OP;

public void init() {

Color k=new Color(120,89,90);

setBackground(k);

t1=new TextField(10);

GridLayout gl=new GridLayout(3,3);

setLayout(gl);

for(int i=0;i<10;i++){

b[i]=new Button(""+i);

}

add=new Button("add");

sub=new Button("sub");

mul=new Button("mul");

div=new Button("div");

mod=new Button("mod");

clear=new Button("clear");

EQ=new Button("EQ");

t1.addActionListener(this);

add(t1);

for(int i=0;i<10;i++){

add(b[i]);

}

add(add);

add(sub);

add(mul);

add(div);

add(mod);

add(clear);

add(EQ);

for(int i=0;i<10;i++){

b[i].addActionListener(this);

}

add.addActionListener(this);

sub.addActionListener(this);

mul.addActionListener(this);

div.addActionListener(this);

mod.addActionListener(this);

clear.addActionListener(this);

EQ.addActionListener(this);

}

public void actionPerformed(ActionEvent ae) {

String str=ae.getActionCommand();

char ch=str.charAt(0);

if ( Character.isDigit(ch))

t1.setText(t1.getText()+str);

else if(str.equals("add")){