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    <pre><code>int A[2][3]={{1,2,3},{4,5,6}}; </code></pre> <p>A 2D array is stored in the memory as follows. Entries in row 0 are stored first followed by row 1 and so on.</p> <p><img src="https://i.stack.imgur.com/1TTUj.png" alt="enter image description here"></p> <p>2-D arrays are represented as a contiguous block of n blocks each with size m (i.e. can hold m integers(or any data type) in each block). The entries are stored in the memory as shown above.Here n represent the number of rows and m represents the number of columns.</p> <p><strong>In Java:</strong></p> <p>As with all arrays, the new keyword must be used to allocate memory for an array. For example,</p> <pre><code> int[][] a = new int[2][4]; </code></pre> <p>This two-dimensional array will have two rows and four columns. This actually allocates 3 objects: a one-dimensional array of 2 elements to hold each of the actual row arrays, and two one-dimensional arrays of 4 elements to represent the contents of the rows.</p> <pre><code> +-----+ +-----+-----+-----+-----+ |a[0] | -&gt; | [0] | [1] | [2] | [3] | | | +-----+-----+-----+-----+ In Java two-dimensional arrays are implemented is a one-dimensional array of one-dimensional arrays -- like this. +-----+ | | +-----+-----+-----+-----+ |a[1] | -&gt; | [0] | [1] | [2] | [3] | +-----+ +-----+-----+-----+-----+ </code></pre> <p>In your case:</p> <pre><code>double[][] array2D = new double [max][1] </code></pre> <p>This actually allocates max+1 objects: a one-dimensional array of max elements to hold each of the actual row arrays, and max one-dimensional arrays of 1 elements to represent the contents of the rows.</p> <p>Let me know if I am wroung .</p>
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    1. POAre there are any important differences between these two ways of writing arrays?
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    1. USAchintya Jha
    1. USAchintya Jha
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    1. COn and m are not indicated in your picture?
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    2. CO-1 For Java that is wrong, the array for the first index stores pointers to arrays for the second index, which contain the values. In particular, the inner arrays may be of different length.
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    3. CO@Magpie Picture is for int A[2][3]={{1,2,3},{4,5,6}}; And description is for 2d array in general.
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