Program Java Sederhana Menggunakan Awt dan Swing (Operasi Aritmetika)

import java.awt.*;

import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class lat1 extends JFrame implements ActionListener
{
JLabel lbl1 = new JLabel(“Masukkan var 1 “);
JTextField txt1=new JTextField(10);
JLabel lbl2 = new JLabel(“Masukkan var 2 “);
JTextField txt2=new JTextField(10);
JLabel lbl3 = new JLabel(“Operasi”);
JComboBox cb1=new JComboBox();
JButton btn1=new JButton(“Jalankan      “);
JButton btn2=new JButton(“Keluar        “);
JTextField txt3=new JTextField(10);
Container c=new Container();
lat1()
{
super(“OPERASI ARITMETIK”);
cb1.addItem(“+”);
cb1.addItem(“-”);
cb1.addItem(“/”);
cb1.addItem(“*”);
c=getContentPane();
c.setLayout(new FlowLayout(FlowLayout.LEFT,50,10));
c.add(lbl1);
c.add(txt1);
c.add(lbl2);
c.add(txt2);
c.add(lbl3);
c.add(cb1);
c.add(btn1);
c.add(btn2);
c.add(txt3);
btn1.addActionListener(this);
btn2.addActionListener(this);
}

public void actionPerformed(ActionEvent e)
{
if(e.getSource()==btn2)
System.exit(0);

if (e.getSource()==btn1)
{
float c=0; float a,b; String s;
a=Float.parseFloat(txt1.getText());
b=Float.parseFloat(txt2.getText());

if (cb1.getSelectedItem()==”+”)
{

c= a+b;

}
if (cb1.getSelectedItem()==”-”)
{
c= a-b;

}
if (cb1.getSelectedItem()==”*”)
{
c= a*b;
}
if (cb1.getSelectedItem()==”/”)
{

c= a/b;

}

s=String.valueOf(c);
txt3.setText(” “+s);

}
}

public static void main(String [] arg)
{
JFrame.setDefaultLookAndFeelDecorated(true);
lat1 x=new lat1();
x.setSize(250,400);
x.setLocation(300,300);
x.setVisible(true);
}
}

BERIKUT INI ADALAH SCREENSHOOT DARI PROGRAM DI ATAS