8 A. Design a AWT program to print the factorial for an input value.

Program:

 import java.awt.*;

import java.awt.event.*;

class Factorial extends Frame implements ActionListener

{

TextField tf;

Button b;

Label n, l, r;

Factorial()

{  

n = new Label("AWT Factorial Program");

l = new Label("Enter number");

r = new Label();

tf = new TextField();

b = new Button("Factorial");  

n.setBounds(30, 40, 200, 20);

l.setBounds(30, 70, 150, 20);

r.setBounds(30, 170, 200, 20);

tf.setBounds(30, 90, 190, 30);

b.setBounds(30, 130, 190, 30);  

add(n);

add(l);

add(r);

add(tf);

add(b);

setSize(250,210);

setLayout(null);//no layout manager  

setVisible(true);//now frame will be visible, by default not visible  

b.addActionListener(this);

addWindowListener(new WindowAdapter()

{  

            public void windowClosing(WindowEvent e)

            {  

                dispose();  

            }  

        });

}

public void actionPerformed(ActionEvent e)

{

if(e.getSource()==b)

{

int num = Integer.parseInt(tf.getText());

r.setText("Factorial of "+num+" is "+getFactorial(num));

}

}

public int getFactorial(int x)

{

int rsl = 1;

for(int i = x; i > 0; --i)

{

rsl *= i;

}

return(rsl);

}

public static void main(String[] args)

{

Factorial factorial = new Factorial();

}

}