Thread: Looping decision?

Hello,

I am trying to figure out how or what looping method
to use to read multiple data from a file.
The file has several income brackets (A, B, & C), and some ratings for product1 and product2.
The data file looks like this:

Code:

A 5 7
A 4 8
A 3 9
B 2 7
C 1 6
C 8 2
A 7 5
B 6 9

What I want to do is read in and calculate the average rating for product 1 (the first number)
that bracket A rated, then bracket B,
and finally C.
I have figured out how to read A or B or C,
by using an if statement and simply changing
the argument to A or B or C,
but I don't know how to have it read the data for A,
then read B, and then C without intervening.
Here is the code I have so far:

Code:

/* This program will display for each income bracket 
(A,B, & C) the average rating for
 * product 1. */

#include <iostream>    // cout, cin, <<, >>
#include <string>      // string
#include <cstdlib>     // exit()
#include <cassert>     // assert
#include <fstream>     // ifstream
using namespace std;

char income,
          c;
int count,
	incomeB5Up,
	prod2Ave;
double prod1Total;
double prod1AveA,
       prod1AveB;
double prod1,
       prod2;

int main()
{
	string fileName;
	cout << "Enter name of file: ";
	getline(cin, fileName);

	ifstream inFile(fileName.data());
	assert(inFile.is_open() );

	while (inFile.get (c) )
	{
		
		 if (c == 'A')  /* get income bracket A information */
		{
			count++;
			inFile >> prod1 >> prod2;			           
			cout << "Product 1 rating: " << prod1 << " Product 2 rating: " 
				 <<  prod2 << " Count: " << count << "\n";  // display prod ratings read from file
            prod1Total += prod1;
			cout << "Prod1Total = " << prod1Total << "\n";    // display prod1 total
			prod1AveA = prod1Total / count;
			cout << "Average for Product 1 in income class A: " << prod1Ave << "\n\n";																			   
		}
		    
        
	}
	cout << "Average for Product 1 in income class A: " << prod1AveA << "\n\n";	

    }

the structure of the file is illusion

read the file as a continuous stream of single characters

encounter A, B, or C - set an index in a two dimensional array of averages

next character should be a digit - set an indexto the product in your two dimensional array

next character is your score - combine it into the average: (average[incomebracket][productnumber] + rating) / 2

hope this helps

I don't know how to use arrays yet.

here is forbidden knowledge

float array[3][3];

now you can access array[x][y], where 0 <= x <= 2 and 0 <= y <= 2 and use it as a spreadsheet-like block of floats