Two Dimensional Array

Often there is a need to store and manipulate two dimensional data structure such as matrices & tables. Here the array has two subscripts. One subscript denotes the row & the other the column. It is referred as two dimensional array.
The declaration of two dimension arrays is as follows:

data_type  array_name[row_size][column_size];

Here, data_type is any valid c data type. array_name specifies name of an array. First value in subscript is represent number of rows and second value represent number of column.

Ex   int x[3][5];

Here x is declared as a matrix having 3 rows( numbered from 0 to 2) and 5 columns(numbered 0 through 4). The first element of the matrix is x[0][0] and the last row last column is x[2][4].

         

	Column[0]	Column [1]	Column [2]	Column [3]	Column [4]
Row[0]	1 [0][0]	2 [0][1]	3 [0][2]	4 [0][3]	5 [0][4]
Row [1]	11 [1][0]	12 [1][1]	13 [1][2]	14 [1][3]	15 [1][4]
Row [2]	21 [2][0]	22 [2][1]	23 [2][2]	24 [2][3]	25 [2][4]

Ac

Ac

According to above representation of two dimensional array, the  3^rd element  of 1^st row represented as x[0][2] and here its value is 3

Initialization of two dimensional array

è    Similar to the one-dimensional the two-dimensional arrays are initialized.

Ex, int array[2][3] = {1,2,3,4,5,6};

In the above case elements of the first row are initialized to 1,2,3 & second row elements are initialized to 4,5,6.

                  

1	2	3
4	5	6

è    The initialization can be done row wise also.

Ex, int array[2][3] = {{1,2,3},{4,5,6}};

è    If the initialization has some missing values then they are automatically initialized to 0.

Ex, int array[2][3] = {{3.4},{5}}

In this case the first two elements of the first  row are initialized to 3,4 ,while the first element of the second row is initialized to 5 & rest all elements are initialized to 0.

                            

3	4	0
5	0	0

       Ex,

       void main()

       {

                 int i,j;

                 int mat[3][3];

                 printf(“\n Input \n” );

                 for(i=0;i<3;i++)

                 {

                          for(j=0;j<3;j++)

                          {

                                    printf(“\n enter element [%d][%d] : “,i+1,j+1);

                                    scanf(“%d”,&mat[i][j]);

                          }

                 }

                 printf(“\n output \n” );

for(i=0;i<3;i++)

                 {

                          for(j=0;j<3;j++)

                          {

                                    printf(“%d”,mat[i][j]);

                          }

                          printf(“\n”);

                 }

      

       }

Posted By : Ruchita Pandya