java GUI multiple buttons output display error?

I am beginner in Java. This is my first project.
The GUI of the code keeps changing every time I run the code.
Sometimes output doesn't even load completely.
This is the code for just initializing a chess board 8X8 jbuttons.

I have put down the images do checkout the hyperlinks below.

Is there any solution that shows the same output every time the code executes?

    package chess;
import game.*;
import javax.swing.*;
import java.awt.*;
import java.io.*;
import java.util.*;
public class board{
static JButton [][] spots =new  JButton [8][8];
public static void main(String[] args){
board b =new board();
b.initializeboard(spots);
}
public void initializeboard(JButton [][] spots){
JFrame f = new JFrame("CHESS");
f.setVisible(true);
f.setSize(800,800);
GridLayout layout =new GridLayout(8,8,1,1); 
f.setLayout(layout);
for(int ver=0;ver<8;ver++){
for(int hor=0;hor<8;hor++){
JButton button = new JButton();
if((ver+hor)%2==0){
button.setBackground(Color.WHITE); }
else{
button.setBackground(new Color(255,205,51)); }
pieces p =new pieces();
spots[ver][hor] = button;
p.setButton(button);
f.add(button);
}
}
} //initialize board
}  // close board

Improper Execution

Correct Execution

Incomplete Execution

> I am beginner in Java.

First of all, class names SHOULD start with an upper case character. Have you even seen a class in the JDK that does not start with an upper case character? Learn by example from the code in your text book or tutorial.

> Is there any solution that shows the same output every time the code executes?

All components should be added to the frame BEFORE the frame is made visible.

When the frame is made visible the layout manager is invoked and the components are given a size/location. If you add components to a visible panel, then you need to invoke revalidate() and repaint() on the panel to make sure the layout manager is invoked.

Must admit I'm not sure why you get this random behaviour. Some components are getting a size/location and other are not even though the layout manager is not invoked.

I would suggest you restructure your code something like:

JPanel chessboard = new JPanel( new GridLayout(8, 8,  1, 1) );
// add buttons to the panel
JFrame frame = new JFrame("CHESS")
frame.add(chessboard, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo( null );
frame.setVisible( true );

Other comments:

1. Don't set the size of the frame. Using 800 x 800 will not make each button 100 x 100. The frame size also include the title bar and borders, so each button size will be less than you expect.

Instead you can create a variable outside of your loops:

Dimension buttonSize = new Dimension(100, 100)

Then when you create the button you use:

button.setPreferredSize( buttonSize );

Now when pack() method is invoked is will size the frame at the preferred size of all the components added to the frame.

2. All Swing components should be create on the Event Dispatch Thread (EDT). Read the section from the Swing tutorial How to Make Frames. The FrameDemo.java code shows you one way to structure your class so that the invokeLater(…) method is used to make sure code executes on the EDT.

3. Don't make your variables static. This indicates incorrect class design. Check out the MenuLook.java example found in How to Use Menus for a slightly different design where your ChessBoard becomes a component created in another class. You can then define your instance variables in that class.