Expert: Zlatko - 1/23/2010

Question
I have translation by Instant C++(C#edition)Tangible Software from C# to C++ as follows:

  for (I = 1; I <= N; I++)
     {
        for (J = 1; J <= N; J++)
        {
           std::cout << "  " +      Strings::Format(A[I][J], "####0.0000");
        }
        std::cout << std::endl;
        std::cout << std::endl;
     }

But compilator C++ Express 2008 shows errors:Console has not been declared and Strings has not been declared. How to correct this array A outputs ?

Answer
Hello Adam,

I am not so good with formatting output to the screen. In C++, output formatting is done by setting flags and other parameters in cout, and by putting stream manipulators into the cout line. See http://www.arachnoid.com/cpptutor/student3.html for more of a tutorial.

In C++ and C#, arrays start at 0, and array indicies go from 0 to size-1

Below is your code with some values assigned to the array A and some formatting.


#include <iostream> // you need this for cout
#include <iomanip> // for setw

// with this you dont have to put std:: in front of cout
using namespace std;

int main(void)
{

   const int N = 5;
   float A[N][N];
   
   std::cout.setf(std::ios_base::fixed);
   std::cout.precision(4);

   for (int I = 0; I < N; I++)
   {
       for (int J = 0; J < N; J++)
       {
           A[I][J] = (float)I + (float)J/10;
           std::cout << "  " <<  std::setw(8) << A[I][J];
       }
       std::cout << std::endl;
       std::cout << std::endl;
   }

   return 0;
}