calculator

package calculator2;

import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;


public class Calculator extends JFrame{

    private Container c;
    private JTextField tf1,tf2,tf3;
    private JButton b1,b2,b3,b4;

    Calculator()
    {
        lol();
    }

    public void lol()
    {
        c = this.getContentPane();
        c.setLayout(null);
        c.setBackground(Color.ORANGE);

        tf1 = new JTextField();
        tf1.setBounds(100,50,100,50);
        c.add(tf1);

        tf2 = new JTextField();
        tf2.setBounds(100,120,100,50);
        c.add(tf2);

        tf3 = new JTextField();
        tf3.setBounds(100,200,100,50);
        tf3.setEditable(false);
        c.add(tf3);

        b1 = new JButton("+");
        b1.setBounds(100,300,100,50);
        c.add(b1);

        b2 = new JButton("-");
        b2.setBounds(220,300,100,50);
        c.add(b2);

        b3 = new JButton("*");
        b3.setBounds(340,300,100,50);
        c.add(b3);

        b4 = new JButton("/");
        b4.setBounds(460,300,100,50);
        c.add(b4);

        Handler h = new Handler();

        b1.addActionListener(h);
        b2.addActionListener(h);
        b3.addActionListener(h);
        b4.addActionListener(h);

    }

    class Handler implements ActionListener{

        @Override
        public void actionPerformed(ActionEvent e){

            String s1 = tf1.getText();
            String s2 = tf2.getText();
            int a = Integer.parseInt(s1);
            int b = Integer.parseInt(s2);
            int c = 0;
            if(e.getSource() == b1)
            {
                c=a+b;
            }
            else if(e.getSource() == b2)
            {
                c=a-b;
            }
            else if(e.getSource() == b3)
            {
                c=a*b;
            }
            else if(e.getSource() == b4)
            {
                c=a/b;
            }

            String result = String.valueOf(c);

            tf3.setText(result);
        }
    }

    public static void main(String[] args) {

        Calculator cal = new Calculator();
        cal.setVisible(true);
        cal.setBounds(200,100,600,450);
        cal.setTitle("CALCULATOR");
    }


}