A C++ multidimensional array has more dimensions identified by the number of subscripts. In this article, you will learn about a two-dimensional array in detail.
Two-dimensional Array
A two-dimensional array has rows and columns. The horizontal arrangement of elements within a two-dimensional array is row and vertical arrangement is a column.
For example,
A[2][4] means that this two-dimensional element is from 3rd row and 5th column. The row or column index starts at 0.
Two-dimensional Array Declaration
To declare a 2d array like any variable does the following.
<data_type><array_name>[m][n];The ism no of rows and equalsn no of columns.
Example #1
int account [3][4];
float boxes[2][3];The example shows that the array account has 3 rows and 4 columns indicated by subscripts.
Two-dimensional Array Initialisation
Initialising two-dimensional array means assigning initial values. There are two ways to do that.
Consider following examples,
int matrix [3][3];
matrix [3][3] = {5,6,8,1,4,7,9,2,0};First, note that the total number of values are equal to 3 × 3 – rows X columns.
int bins[2][2];
bins[2][2] = {{23, 45},{78, 43}};The first internal brace is the first row and never changes. Similarly, the second brace is the second row.
Also, you can initialise 2a d array dynamically. See the example program below.
/* Program to demonstrate
two-dimensional array
*/
#include <cstdlib>
#include <iostream>
using namespace std;
int main()
{
int sq_matrix[3][3];
int i,j;
//Reading values for matrix
cout << "Enter matrix values";
for(i =0;i<3;i++)
{
for(j=0;j<3;j++)
{
cin >> sq_matrix [i][j];
}
}
//print the array
for(i =0;i<3;i++)
{
for(j=0;j<3;j++)
{
cout << sq_matrix [i][j] << " ";
}
cout << endl;
}
system("PAUSE");
return EXIT_SUCCESS;
}Output
Enter matrix values4
8
9
0
8
4
2
9
7
4 8 9
0 8 4
2 9 7