CSC133 Intro to CS in C++: Two Dimensional Array Example

Two Dimensional Array Example

//  this program reads numbers into a 2D array with 3 rows and 4
//  columns, prints a row, prints a column, then prints the whole
//  array

#include <iostream.h>
#include <iomanip.h>

int main()
{
   int sample[3][4];
   int i,j;

//  read values into the whole array
   for (i = 0 ; i < 3 ; i++)
   {
      cout << "Enter 4 numbers: ";
      for (j = 0 ; j < 4 ; j++)
         cin >> sample[i][j];
   }

//  print one row
   cout << "The first row contains: ";
   for (j = 0 ; j < 4 ; j++)
      cout << sample[0][j] << "  ";
   cout << endl;

//  print one column
   cout << "The second column contains: ";
   for (i = 0 ; i < 3 ; i++)
      cout << sample[i][1] << "  ";
   cout << endl;

//  print the whole array, row by row
   cout << "\nThe whole array:\n";
   for (i = 0 ; i < 3 ; i++)
   {
      cout << "Row " << i << ": ";
      for (j = 0 ; j < 4 ; j++)
         cout << setw(4) << sample[i][j] << "  ";
      cout << endl;
   }

}

Sample Execution

Enter 4 numbers: 2 4 6 8
Enter 4 numbers: 40 30 20 10
Enter 4 numbers: 12 9 6 3
The first row contains: 2  4  6  8
The second column contains: 4  30  9

The whole array:
Row 0:    2     4     6     8
Row 1:   40    30    20    10
Row 2:   12     9     6     3