Slip No 4 Q B

Q. Write a java program using Applet to implement a simple arithmetic calculator.[25 M]

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

/*
<applet code="SimpleCalculator" width=300 height=200>
</applet>
*/

public class SimpleCalculator extends Applet implements ActionListener {

    TextField t1, t2, t3;
    Button add, sub, mul, div;

    public void init() {
        // Labels
        add(new Label("First Number:"));
        t1 = new TextField(10);
        add(t1);

        add(new Label("Second Number:"));
        t2 = new TextField(10);
        add(t2);

        // Buttons
        add = new Button("Add");
        sub = new Button("Sub");
        mul = new Button("Mul");
        div = new Button("Div");

        add(add);
        add(sub);
        add(mul);
        add(div);

        // Result
        add(new Label("Result:"));
        t3 = new TextField(15);
        add(t3);

        // Register events
        add.addActionListener(this);
        sub.addActionListener(this);
        mul.addActionListener(this);
        div.addActionListener(this);
    }

    public void actionPerformed(ActionEvent e) {
        double a = Double.parseDouble(t1.getText());
        double b = Double.parseDouble(t2.getText());
        double result = 0;

        if(e.getSource() == add)
            result = a + b;
        else if(e.getSource() == sub)
            result = a - b;
        else if(e.getSource() == mul)
            result = a * b;
        else if(e.getSource() == div)
            result = a / b;

        t3.setText(String.valueOf(result));
    }
}