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

class Ex3 {

  // Screen is divided into many pixels
  // Pixel is a unit of drawing
  final static int XPIXELS = 800;
  final static int YPIXELS = 600;

  public static void main(String[] args) {

    // JFrame is a predefined class
    JFrame jf = new JFrame("Example-3 in Java GUI");

    // What to do when window is closed?
    jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // Set the size of the window (in terms of pixels)
    jf.setSize(new Dimension(XPIXELS, YPIXELS));

    // Create components
    Container con = jf.getContentPane();
    // Create a label
    JLabel label = new JLabel("Example-3");
    con.add(label);
    // Create a button
    JButton btn = new JButton("Click-me");
    con.add(btn);

    // Show the frame
    jf.setVisible(true);

    // Note: main does not exit here

  } // End main()

}