C# - Multidimensional Arrays
C# allows multidimensional arrays. Multi-dimensional arrays are also called rectangular array. You can declare a 2-dimensional array of strings as −
string [,] names;
or, a 3-dimensional array of int variables as −
int [ , , ] m;
Two-Dimensional Arrays
The simplest form of the multidimensional array is the 2-dimensional array. A 2-dimensional array is a list of one-dimensional arrays.
A 2-dimensional array can be thought of as a table, which has x number of rows and y number of columns. Following is a 2-dimensional array, which contains 3 rows and 4 columns −
Thus, every element in the array a is identified by an element name of the form a[ i , j ], where a is the name of the array, and i and j are the subscripts that uniquely identify each element in array a.
Initializing Two-Dimensional Arrays
Multidimensional arrays may be initialized by specifying bracketed values for each row. The Following array is with 3 rows and each row has 4 columns.
int [,] a = new int [3,4] { {0, 1, 2, 3} , /* initializers for row indexed by 0 */ {4, 5, 6, 7} , /* initializers for row indexed by 1 */ {8, 9, 10, 11} /* initializers for row indexed by 2 */ };
Accessing Two-Dimensional Array Elements
An element in 2-dimensional array is accessed by using the subscripts. That is, row index and column index of the array. For example,
int val = a[2,3];
The above statement takes 4th element from the 3rd row of the array. You can verify it in the above diagram. Let us check the program to handle a two dimensional array −
Live Demousing System; namespace ArrayApplication { class MyArray { static void Main(string[] args) { /* an array with 5 rows and 2 columns*/ int[,] a = new int[5, 2] {{0,0}, {1,2}, {2,4}, {3,6}, {4,8} }; int i, j; /* output each array element's value */ for (i = 0; i < 5; i++) { for (j = 0; j < 2; j++) { Console.WriteLine("a[{0},{1}] = {2}", i, j, a[i,j]); } } Console.ReadKey(); } } }
When the above code is compiled and executed, it produces the following result −
a[0,0]: 0 a[0,1]: 0 a[1,0]: 1 a[1,1]: 2 a[2,0]: 2 a[2,1]: 4 a[3,0]: 3 a[3,1]: 6 a[4,0]: 4 a[4,1]: 8