JSON.Net incorrectly serializes a two dimensional array to a one dimension

Question

Trying to convert a two dimensional array to a two dimensional JSON.Net array.

Is there something wrong with the code below? Or just isn't this supported by JSON.Net?

        var A = new int[2, 4] { { 1, 1, 1, 1 }, { 2, 2, 2, 2 } };

        Console.WriteLine(JsonConvert.SerializeObject(A));

        // CONSOLE: [1,1,1,1,2,2,2,2]  
        //
        // NB. displays a one dimensional array 
        // instead of two e.g. [[1,1,1,1],[2,2,2,2]]

score 11 · Answer 1 · answered Aug 06 '12 at 17:33

11

Starting with Json.Net 4.5 Relase 8 multimensional arrays are supported.

So your example will work now and produce the following JSON:

[ [ 1, 1, 1, 1 ], [ 2, 2, 2, 2 ] ]

answered Aug 06 '12 at 17:33

Timm

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score 10 · Accepted Answer · edited May 23 '17 at 10:34

10

Javascript doesn't have the notion of a 2D array in the same sense that C# does. In order to get an array like that described here, you'll need to create an array of arrays instead.

// output: [[1,1,1,1],[2,2,2,2]]
var a = new int[][] { new[]{ 1, 1, 1, 1 }, new[]{ 2, 2, 2, 2 } };

Update:

It sounds like JSON.NET now converts multidimensional arrays into an array of arrays in JSON, so the code in the OP will work the same as if you used the code above.

edited May 23 '17 at 10:34

Community

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answered Nov 15 '11 at 16:17

StriplingWarrior

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+1: I'll play with a convert 2d array to a jagged array then. Maybe that'll do it. ty. – sgtz Nov 15 '11 at 16:20
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this answer is out of date. see @Timm's below – Robert Levy Nov 15 '13 at 01:58
@RobertLevy: Thanks for bringing that to my attention. – StriplingWarrior Nov 15 '13 at 18:52

score 4 · Answer 3 · answered Nov 15 '11 at 16:13

4

when you define an array like you did it isnt a matrix its the same array with two dimensions that why SerializeObject serialize it as the same array.

answered Nov 15 '11 at 16:13

Liran

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+1... I'm thinking of a matrix and a 2d array as conceptually being the same thing... so I'm finding it hard to follow. You mean in terms of the underlying .net representation? – sgtz Nov 15 '11 at 16:25

score 1 · Answer 4 · answered Nov 15 '11 at 21:08

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I'm surprised it works at all. Json.NET doesn't support multidimensional arrays. Use a jagged array instead.

answered Nov 15 '11 at 21:08

James Newton-King

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Can you give any reason why it doesn't support this? Is it because of the ambiguity when converting back from JSON? – Timm Apr 21 '12 at 09:22

JSON.Net incorrectly serializes a two dimensional array to a one dimension

4 Answers4

Update:

Linked

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