1.26. C # multidimensional array

C # supports multidimensional arrays. A multidimensional array is also called a rectangular array.

You can declare a string two-dimensional array of variables, as follows:

string [,] names;

Alternatively, you can declare a int three-dimensional array of variables, as follows:

int [ , , ] m;

1.26.1. Two-dimensional array #

The simplest form of a multidimensional array is a two-dimensional array. A two-dimensional array is essentially a list of one-dimensional arrays.

A two-dimensional array can be thought of as a table with x rows and y columns.

Therefore, each element in the array is in the form of a[ i , j ] identified by the element name of the, where a is the array name i and j are subscripts that uniquely identify each element in a .

1.26.2. Initialize two-dimensional array #

Multidimensional arrays can be initialized by specifying values for each rowin parentheses. The following is an array with three rows and four columns.

int [,] a = new int [3,4] {
 {0, 1, 2, 3} ,   /*  initialize rows with index number 0 */
 {4, 5, 6, 7} ,   /*  initialize rows with index number 1 */
 {8, 9, 10, 11}   /*  initialize rows with index number 2 */
};

1.26.3. Access two-dimensional array elements #

Elements in a two-dimensional array are accessed by using subscripts (that is, row and column indexes of the array). For example:

int val = a[2,3];

The above statement will get the fourth element in the third line of the array. You can verify it through the diagram above. Let’s take a look at thefollowing program, where we will use nested loops to deal with two-dimensional arrays:

Example #

using 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 the values of each element in the array */
            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 results:

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