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    <p>So, let's get the easy question out of the way: as far as 2D arrays goes, it's actually up to you to decide whether it's [row][column] or [column][row]. Java doesn't care. As long as you treat it consistently throughout your app you can think of it whichever way makes most sense to you. If it helps (and it might not) remember that a 2D array is just an array of arrays.</p> <p>As for MVC, this is how I think of it: M is the model of the data (the array, for example), V is the visual representation of that data (displayed to the user, as a chessboard perhaps) and C is the controller, which connects the two and transmits changes in one to the other, translating or otherwise interpreting user actions as necessary. If the user drags a chess piece from one square to another, the Controller interprets this gesture, implements the logic that decides if the maneuver is legal and what side-effects it might have (like capturing a piece), and updates both the model and the view as required. The confusion lies in that most UI toolkits, Java's included, often blur the boundaries between these pieces, so that bits of the Controller end up in the View, or the Model, or both. It's not necessarily a problem, but it's something to be aware of. The main thing is to try, as far as possible, to keep a well-defined boundary between the data, the view, and the logic that interfaces the two.</p> <p>To answer your question about drawing and co-ordinates, it really depends how you implement your chessboard UI. You could implement it entirely using Java Swing, for example, and by making clever use of JLabels, JPanels, and maybe a GridLayout, or perhaps even a JTable, you could almost (almost!) have an automagially updating chessboard. On the other hand, you could implement your own UI classes from scratch, making use of Java2D and the drawing primitives it provides, and then you'd have to do more management of co-ordinates and such.</p>
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    1. USStewart Murrie
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    1. COAbout the arrays, how do I choose? For example, my array has as many columns as rows. If I loop through the array using a for loop and the integer column whichs increments each cycle, and I do something like [column][2]. How do I then know if it's going to see the number 2 as a column or row? Column 2 and row 2 are pretty different.
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    2. COWhat I don't get is how do I connect a graphics object in V to an element in the M array? I could maybe call a method that creates and draws the "graphical" square in the constructor for the "data" square that is in the array but then the question still remains. If a user clicks the "graphical" square how does the model connect that to the square in the array? How does the "data" square relate?
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    3. CO@Alex: maybe I'm not understanding your question, but 'it' doesn't know anything about columns or rows - that's up to your interpretation of the data. Think of it this way. You have int[][] board = new int[8][8]. You can then say int[] column5 = board[5]. The variable column5 now holds a simple integer array. You can then say int cellValue = column5[3]. You've now picked whatever's in the 4th slot of the int[] array that's held in column5, which you can interpret as picking the 4th row from your matrix. All you're really doing is 1st choosing a sub-array, and then an item from that.
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