Java. Painted array is automaticly transposed

Question

I recently started my adventure with Java, I use IntelliJ IDEA 13.1.1. My problem is: When I want to paint an array on the screen it's being painted as it was transposed.

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

@SuppressWarnings("serial")
public class Main extends JPanel
{
    public int tab[][]=new int[3][6];
    public static final int CANVAS_WIDTH=1280;
    public static final int CANVAS_HEIGHT=1024;
    public Main()
    {
        for(int i=0; i<3; i++)
            for(int j=0;j<6;j++)
                tab[i][j]=3*j+i*2;
        tab[1][4]=99;
        setPreferredSize(new Dimension(CANVAS_WIDTH, CANVAS_HEIGHT));
    }
    @Override
    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        setBackground(Color.BLACK);
        g.setColor(Color.WHITE);
        for(int i=0; i<3; i++)
            for(int j=0;j<6;j++)
                g.drawString(tab[i][j]+"", 20+i*20, 20+j*20);
    }
    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                JFrame frame=new JFrame("tests");
                frame.setContentPane(new Main());
                frame.pack();
                frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }
}

As a result on screen I get:

0 2 4

3 5 7

6 8 10

9 11 13

12 99 16

15 17 19

When I display the array outside painting function using System.out.print I get:

0 3 6 9 12 15

2 5 8 11 99 17

4 7 10 13 16 19

Does anyone know what is causing this? It makes working with arrays that I want to paint data from not as intuitive and quite inconvenient.

Answer 1

Try writing your method like this:

g.drawString(tab[i][j]+"", 20+j*20, 20+i*20);

(i and j are swapped in the last two arguments)