Problem with adding an arraylist of jbuttons to a jpanel

Hello, I'm having a problem with the following code where I keep getting the following error:

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 9, Size: 9
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at MoleGUI.<init>(MoleGUI.java:45)
at MoleMain.main(MoleMain.java:6)

Can anyone look at my code and tell me what the problem is please?
Btw I do have a main class which can run this (just saying lol)

Quote:

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import javax.swing.*;
import javax.swing.Timer;
import java.util.*;
import java.awt.event.*;
import java.awt.*;

public class MoleGUI implements ActionListener{

JFrame field;
JPanel panel;
JButton h1,h2,h3,h4,h5,h6,h7,h8,h9;
Timer t = new Timer(5, this);
int counter;
ArrayList<JButton> holes;


public MoleGUI() {
field = new JFrame("Whack-a-Mole");
panel = new JPanel(new GridLayout(3,3));
field.setContentPane(panel);
field.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);

holes = new ArrayList<JButton>();

holes.add(h1 = new JButton());
holes.add(h2 = new JButton());
holes.add(h3 = new JButton());
holes.add(h4 = new JButton());
holes.add(h5 = new JButton());
holes.add(h6 = new JButton());
holes.add(h7 = new JButton());
holes.add(h8 = new JButton());
holes.add(h9 = new JButton());

panel.add(holes.get(1));
panel.add(holes.get(2));
panel.add(holes.get(3));
panel.add(holes.get(4));
panel.add(holes.get(5));
panel.add(holes.get(6));
panel.add(holes.get(7));
panel.add(holes.get(8));
panel.add(holes.get(9));

holes.get(1).addActionListener(this);
holes.get(2).addActionListener(this);
holes.get(3).addActionListener(this);
holes.get(4).addActionListener(this);
holes.get(5).addActionListener(this);
holes.get(6).addActionListener(this);
holes.get(7).addActionListener(this);
holes.get(8).addActionListener(this);
holes.get(9).addActionListener(this);

//counter = 0;
//t.start();
}

public void display(){
field.pack();
field.setVisible(true);
field.resize(500,500);
//run();
}

public void run()
{

}

public void actionPerformed(ActionEvent e)
{

}

}

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Array indexes are zero based. If there are 9 elements in an array, the max index is 8 (the length-1)

You should look at using a for loop controlled by the size of the array instead of hardcoding all those separate indexing statements.

Quote:

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Originally Posted by Norm

Array indexes are zero based. If there are 9 elements in an array, the max index is 8 (the length-1)

You should look at using a for loop controlled by the size of the array instead of hardcoding all those separate indexing statements.

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Haha wow it's funny because I knew that too. I guess I just didn't catch the error in the code. Thanks for the help :cool:

Quote:

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Haha wow it's funny because I knew that too. I guess I just didn't catch the error in the code. Thanks for the help

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And don't forget to thanks or hit the Rep button (Star) when someone helps you. Good Luck and mark this as Solved.