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POHow do I reference multi-dimensional arrays?
 

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    <p>I'm trying to understand multi-dimensional arrays in Java, but I think it applies to any language. Please consider this snippet I found on the web:</p> <pre><code> //************************************ // static array initialization //************************************ byte[][] smallArray = { { 10, 11, 12, 13 }, { 20, 21, 22, 23 }, { 30, 31, 32, 33 }, { 40, 41, 42, 43 }, }; // Display the array element at row 2, column 3 System.out.println(smallArray[1][2]); // Value is 21 </code></pre> <p>Why is it 21? I thought it would be 22.</p> <p>I looked this up because I am trying to figure out what length means in this context:</p> <pre><code>public class Pieces { int thePieces[][][]; public Pieces(){ } public int[][][] createPieces(){ /* pieces in order below **** [0] ** ** * **** * **** *** * ** ** ** ** [6] * * * */ int myPieces [][][] = { { //square {0,0}, {1,0}, {1,1}, {0,1} }, { //T {-1,0}, {0,0}, {0,1}, {1,0} } }; thePieces = myPieces; return thePieces; } public void printPieces(){ System.out.println(thePieces[0][0].length); } } </code></pre> <p>I am trying to learn java by creating a tetris clone. What I don't understand is why length is required to use [][]. It was the only way I could get to work. I tried thePieces[0][0][0].length but got an error that I did not understand? </p> <p>Why don't I have to put [][][] to get the reference? I saw online where the first "level" of the array was referenced myArray.length instead of myArray[].length. What then am I saying with myArray[][].length (it seems 2nd,3rd levels but I'm not getting what I expect)?</p> <p>I ran my piece code and got 2. I have no idea why it is two. Is it because I have two sets at the third level? I expected to get four because of the four sets of points.</p> <p>Thank you for your helping me understand.</p> <p>EDIT: I figured out why it is two. It is giving me my two points in the innermost set. If I wanted four I would use thePieces[0].length. But what about the first example? Is it a typo?</p>
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