GUI based Calculator in Java

This is a simple calculator which can add, subtract, multiply and divide two numbers. There’s not much logic involved in the program, just made it to demonstrate different GUI elements.

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.*;

public class Calculator {

JButton add,divide,multiply,sub;

JTextField num1,num2;

JLabel ans;

public Calculator(){

JFrame frame = new JFrame("Calculator - MyCoding.net");

num1 = new JTextField (10);

ans = new JLabel("");

num2 = new JTextField (9);

add = new JButton ("+");

divide = new JButton("/");

multiply = new JButton("X");

sub = new JButton ("-");

frame.setVisible(true);

frame.setBounds(500, 200, 290, 210);

frame.setLayout(new GridLayout(0,2,1,1));

frame.add(new JLabel("First Number: "));

frame.add(num1);

frame.add(new JLabel("Second Number: "));

frame.add(num2);

frame.add(new JLabel("Answer: "));

frame.add(ans);

frame.add(add);

frame.add(sub);

frame.add(multiply);

frame.add(divide);

add.addActionListener(new HandlerClass());

sub.addActionListener(new HandlerClass());

divide.addActionListener(new HandlerClass());

multiply.addActionListener(new HandlerClass());

}

public static void main(String[] args) {

new Calculator();

}

public class HandlerClass implements ActionListener{

public void actionPerformed(ActionEvent ae){

try{

int fnum = Integer.parseInt(num1.getText());

int snum = Integer.parseInt(num2.getText());

if(ae.getSource()== add){

ans.setText(String.valueOf(fnum+snum));

}

else if(ae.getSource()== sub){

ans.setText(String.valueOf(fnum-snum));

}

else if(ae.getSource()== multiply){

ans.setText(String.valueOf(fnum*snum));

}

else{

ans.setText(String.valueOf(fnum/snum));

}

}catch(Exception e)

{

JOptionPane.showMessageDialog(null, "Please enter a valid number");

e.printStackTrace();

}

Output: Output

Executable JAR file: http://www.mediafire.com/?6bbweg0ivd8id6n

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