bool [,] - What does this syntax mean in c#? -

i found in legacy code following line:

protected bool[,] pixelschecked;

what [,] mean here?

it's two-dimensional array.

in .net can have 2 types of arrays aren't single dimension:

multidimensional arrays:

int[,] a;    // 2 dimensions int[,,] b;   // 3 dimensions, , on

jagged arrays (arrays of arrays):

int[][] a;   // array of arrays of ints int[][][] a; // array of arrays of arrays of ints

in both cases need initialize variable before using though.

usage different, in first case:

int value = a[1, 2]; // note comma, , single pair of brackets

in second case, need address each array separately:

int value = a[1][2]; // first [1] will return array, , take                      // 3rd element (0-based) of

also remember can initialize multidimensional array in 1 statement:

int[,] = new int[10, 20];

whereas single statement jagged array create single array full of null-references:

int[][] = new int[10][];

you need initialize elements of array corresponding array references, here's quick way linq in 1 statement:

int[][] a = enumerable.range(0, 10).select(new int[20]).toarray(); // 10 x 20

also see msdn page on subject more information.

fun fact: jitter produces faster code accessing jagged arrays multidimensional arrays, see this question more information.

Three