16.4

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;
import javax.swing.border.LineBorder;

public class Test_16_4 extends JFrame{
JTextField JT1 = new JTextField(5);
JTextField JT2 = new JTextField(5);
JTextField JT3 = new JTextField(5);
JButton JB_add = new JButton("Add");
JButton JB_sub = new JButton("Subtract");
JButton JB_mul = new JButton("Multiply");
JButton JB_div = new JButton("Divide");

public Test_16_4(){
JPanel JP1 = new JPanel();
JPanel JP2 = new JPanel();

NewListener nl = new NewListener();

setLayout(new FlowLayout());
JP1.add(new JLabel("Number 1"));
JP1.add(JT1);
JP1.add(new JLabel("Number 2"));
JP1.add(JT2);
JP1.add(new JLabel("Result"));
JP1.add(JT3);
JP1.setBorder(new LineBorder(Color.BLACK,1));

setLayout(new FlowLayout());
JP2.add(JB_add);
JP2.add(JB_sub);
JP2.add(JB_mul);
JP2.add(JB_div);
JP2.setBorder(new LineBorder(Color.black,1));

setLayout(new BorderLayout(0,5));
add(JP1,BorderLayout.CENTER);
add(JP2,BorderLayout.SOUTH);

JB_add.addActionListener(nl);
JB_sub.addActionListener(nl);
JB_mul.addActionListener(nl);
JB_div.addActionListener(nl);
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Test_16_4 T1 = new Test_16_4();
T1.pack();
T1.setTitle("Test_16_4");
T1.setLocationRelativeTo(null);
T1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
T1.setVisible(true);
}

class NewListener implements ActionListener{

@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
double number1 = Double.parseDouble(JT1.getText());
double number2 = Double.parseDouble(JT2.getText());
if(e.getSource() == JB_add){
JT3.setText(number1+number2+"");
}else if(e.getSource() == JB_sub){
JT3.setText(number1-number2+"");
}else if(e.getSource() == JB_mul){
JT3.setText(number1*number2+"");
}else if(e.getSource() == JB_div){
JT3.setText(number1/number2+"");
}
}

}
}