basic with swing and java visual programming

main.java

//Step 1: import lib
import javax.swing.*;
import java.awt.*;

public class Main {
    public static void main(String[] args) {
        //step 2: Top level Frame / window
        JFrame frame= new JFrame();

        //step 3: container to frame
        Container container= frame.getContentPane();

        //step 4: container layout
        container.setLayout(new FlowLayout());

        //step 5: UI component to container
        JButton btn= new JButton("hello");
        btn.setBackground(Color.PINK);
        container.add(btn);

        //Step 6: set visibility of frame
        frame.setVisible(true);
        frame.setSize(200,400);
        frame.setTitle("title");
        frame.setBackground(Color.BLUE);

        //step 7: sed default on close
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }
}