This dosnt make any sense..

Question

can someone explaine why
import javax.swing.*;
import java.awt.Dimension;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener; 
import java.applet.*;
import java.awt.*;
import java.awt.Window;
public class applet extends JApplet implements ActionListener {
     JButton PushMe;
     JTextField TextInput;
     JTextArea TextBox;
     JFrame NewWindow;
     Choice Select;
     String text = new String("hello world!");
     int i = (int) 0;
     public void init() {
          Container c = getContentPane();
          c.setBackground(Color.BLUE);
          c.setLayout(new FlowLayout());
          NewWindow = new JFrame("test");
          PushMe = new JButton("Push Me!");
          Select = new Choice();
          TextInput = new JTextField(15);
          Select.add("--SELECT--");
          Select.add("1");
          Select.add("2");
          PushMe.addActionListener(this);
          TextInput.addActionListener(this);
          NewWindow.setSize(500,500);
          NewWindow.getContentPane().setBackground(Color.BLUE);
          NewWindow.getContentPane().add(Select,BorderLayout.CENTER);
          NewWindow.setLocation(1,350);
          c.add(new JScrollPane(PushMe));
     public void actionPerformed(ActionEvent event) {
          if(event.getSource() == PushMe && i == 0) {
               NewWindow.show();
               i = (int) 1;
          else if(event.getSource() == PushMe && i == 1) {
               NewWindow.hide();
               i = (int) 0;
          if(event.getSource() == TextInput) {
               System.out.println(event.getSource());
}has a background color of blue & shows the Choice() but
import javax.swing.*;
import java.awt.Dimension;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener; 
import java.applet.*;
import java.awt.*;
import java.awt.Window;
public class applet extends JApplet implements ActionListener {
     JButton PushMe;
     JTextField TextInput;
     JTextArea TextBox;
     JFrame NewWindow;
     Choice Select;
     String text = new String("hello world!");
     int i = (int) 0;
     public void init() {
          Container c = getContentPane();
          c.setBackground(Color.BLUE);
          c.setLayout(new FlowLayout());
          NewWindow = new JFrame("test");
          PushMe = new JButton("Push Me!");
          Select = new Choice();
          TextInput = new JTextField(15);
          Select.add("--SELECT--");
          Select.add("1");
          Select.add("2");
          PushMe.addActionListener(this);
          TextInput.addActionListener(this);
          NewWindow.setSize(500,500);
          NewWindow.getContentPane().setBackground(Color.BLUE);
          NewWindow.getContentPane().add(TextInput,BorderLayout.CENTER);
          NewWindow.setLocation(1,350);
          c.add(new JScrollPane(PushMe));
     public void actionPerformed(ActionEvent event) {
          if(event.getSource() == PushMe && i == 0) {
               NewWindow.show();
               i = (int) 1;
          else if(event.getSource() == PushMe && i == 1) {
               NewWindow.hide();
               i = (int) 0;
          if(event.getSource() == TextInput) {
               System.out.println(event.getSource());
}shows the JTextField but with a white background &
import javax.swing.*;
import java.awt.Dimension;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener; 
import java.applet.*;
import java.awt.*;
import java.awt.Window;
public class applet extends JApplet implements ActionListener {
     JButton PushMe;
     JTextField TextInput;
     JTextArea TextBox;
     JFrame NewWindow;
     Choice Select;
     String text = new String("hello world!");
     int i = (int) 0;
     public void init() {
          Container c = getContentPane();
          c.setBackground(Color.BLUE);
          c.setLayout(new FlowLayout());
          NewWindow = new JFrame("test");
          PushMe = new JButton("Push Me!");
          Select = new Choice();
          TextInput = new JTextField(15);
          Select.add("--SELECT--");
          Select.add("1");
          Select.add("2");
          PushMe.addActionListener(this);
          TextInput.addActionListener(this);
          NewWindow.setSize(500,500);
          NewWindow.getContentPane().setBackground(Color.BLUE);
          NewWindow.getContentPane().add(PushMe,BorderLayout.CENTER);
          NewWindow.setLocation(1,350);
          c.add(new JScrollPane(PushMe));
     public void actionPerformed(ActionEvent event) {
          if(event.getSource() == PushMe && i == 0) {
               NewWindow.show();
               i = (int) 1;
          else if(event.getSource() == PushMe && i == 1) {
               NewWindow.hide();
               i = (int) 0;
          if(event.getSource() == TextInput) {
               System.out.println(event.getSource());
}displays a blue background but no JButton() ?
thanks

Answer 1

For applet one: it is recommended that we not mix AWT and Swing components. Choice is an AWT component.
For applet 2: when you add somethting to a center section of a BorderLayout it expands to fill the entire section. Add it to a JPanel and then add the JPanel to the center section. The JPanel expands to fill the center section and the JTextField is left to appear at its preferred size.
For applet number 3: you added the button to the JFrame content pane and then added it to the JScrollPane. Adding it to the JScrollPane removes it from the JFrame content pane. You can only put a component in one place at a time.