CSC133 Intro to CS in C++: Two Dimensional Arrays and Functions

Two Dimensional Arrays and Functions

//  this program uses functions to read values into a 2D array and
//  print it out

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

const int NUMROWS = 10;
const int NUMCOLS = 8;

void fillArray(int [][NUMCOLS],int&,int&);
void printArray(int [][NUMCOLS],int,int);

int main()
{
   int matrix[NUMROWS][NUMCOLS];
   int nrows;
   int ncols;

   fillArray(matrix,nrows,ncols);
   printArray(matrix,nrows,ncols);

   return 0;
}

//  this function asks the user how many rows and columns will be
//  used and then reads the values. the parameters rows and cols
//  return the number of rows and columns used
void fillArray(int matrix[][NUMCOLS], int& rows, int& cols)
{

//  ask the user how many rows and columns he or she would like to use
   cout << "How many rows would you like to fill (max "
        << NUMROWS << ")?  ";
   cin >> rows;
   cout << "How many columns would you like to fill (max "
        << NUMCOLS << ")?  ";
   cin >> cols;
   for (int i = 0 ; i < rows ; i++)
   {
      cout << "Enter the values for the " << (i+1) << "th row: " << endl;
      for (int j = 0 ; j < cols ; j++)
         cin >> matrix[i][j];
   }
}

//  this function prints out the values that were read into the array
//  values are printed in row order
void printArray(int matrix[][NUMCOLS], int rows, int cols)
{
   cout << endl << endl << "The matrix:\n";
   for (int i = 0 ; i < rows ; i++)
   {
      for (int j = 0 ; j < cols ; j++)
         cout << setw(5) << matrix[i][j];
      cout << endl;
   }
}

Sample Execution

How many rows would you like to fill (max 10)?  4
How many columns would you like to fill (max 8)?  6
Enter the values for the 1th row:
1 2 3 4 5 6
Enter the values for the 2th row:
222 3 444 55 6 777
Enter the values for the 3th row:
987 6 54 32 111 20
Enter the values for the 4th row:
6 44 7 88 3 2


The matrix:
    1    2    3    4    5    6
  222    3  444   55    6  777
  987    6   54   32  111   20
    6   44    7   88    3    2