need just a little help.

ok i posted in a exiting thread before as my question was relevant to that thread. Now im starting this thread so i wont hog the other person's thread.

so far with the help of various people like, hk_mp5kpdw andyhunter, and 7stud ive managed to get a little further on my program but im still having some confusing results.

here is the code

Code:

#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

const int FILENAMELEN =20, ARRAYLEN =20;

class array
{
    public:
            int      readarray();
            array0();
            float      finddev();
            float  findaverage();
            float writeresults();

    private:
            int            j;
            int            i;
            int        count;
            int  numbers[20];
            float        sum;
            float    average;
            float        var;
            float        std;
            float  sqrofsums;
            float  sumofsqrs;
            char  values[20];
            char     filename[FILENAMELEN];
            ifstream inflie;
            //int currentChar;
            
    
};
array::array0()
{
    count =0;

}

int array::readarray()
{
    
    char filename[FILENAMELEN];
    char inchar;
    ifstream infile;
    //currentChar = 0;
    count = 0;
    

    cout<<"Enter filename->" <<'\t';
    cin>> filename;
/*
    for (i=0; i<20; i++)
    {
        numbers[i]=0;
    }*/

    //openfile
    infile.open(filename);
    //if you cant open the file, print error message
    if (!infile)
    {
        cerr<< "Cannot open " <<filename << endl;
        exit(1);
    }

        //Read the file 
        
        while(!infile.eof() && count < 20)
        {
        
        //something is going on right here? getting mixed output
            
            infile.getline(values,20); 
            cout<<values<<endl;

            inchar =infile.get();
            cout <<inchar<<endl;        
            {
                if( infile >> numbers[count]) ++count;
                else break;

            }
                
        }    
        
        infile.close();
        return(0);
}

//find the average
float array::findaverage()
{
    
    sum      = 0.0;
    average  = 0.0;

    for (j=0;j<count;j++)
    {
        sum+=numbers[j];
        
    }
        average =sum/j;
        return average;
}

//find the std
float array::finddev()
{
    sum       = 0.0;
    var       = 0.0;
    std       = 0.0;
    sqrofsums = 0.0;
    sumofsqrs = 0.0;
    
    //sum of the numbers squared
    for (j=0;j<count; j++)
    {
        sum+=numbers[j];
    }
    sqrofsums =(float)pow(sum,2);

    //sum of squared numbers
    for(j=0;j<count; j++)
    {
        sumofsqrs+=numbers[j] *numbers[j];
    }

    //variance
        var =(sumofsqrs -(sqrofsums/j));
        var = (var/j-1);

        std = (float)sqrt(var);

    return std;
}

//display the results
float array::writeresults()
{
        

    cout << "The average is:  " << findaverage(); 
    cout << endl;
    cout << "The standard deviation is:   " << finddev(); 
    cout << endl;
    
    return 0;
}

int main()
{
    int numbers[20];
    int *pn=numbers;

    array myarray;
    myarray.readarray();
    myarray.writeresults();

    return 0;
}

the text file is as follows
array1.txt

Code:

5
4
3
2
6
5

the result i get is

Code:

Enter filename->        array1.txt
5
4

2

5
The average is:  4.5
The standard deviation is:   1.11803
Press any key to continue

Alright the only thing you are trying to do is read in the integers stored in the file right? Thus you can greatly reduce the size and complexity of your read loop. Something like this would suffice:

Code:

//in class def
int count;
int num;
int numbers[20];

//your read loop

while(!((myFile >> num)==NULL)) { //check for EOF
        numbers[count++] = num; // load contents of file into your int array
}

Of course you would also add in a check to ensure you do not go outside of the bounds of the array.

myFile here would be the infile?

yes, and don't forget to add a bounds check for your array, aka count cannot be allowed to exceed 20.

Code:

int array::readarray()
{
	
    //char inchar;
	ifstream infile;
	//currentChar = 0;
	count = 0;
	

    cout<<"Enter filename->" <<'\t';
    cin>> filename;

/*	for (i=0; i<20; i++)
	{
		numbers[i]=0;
	}*/

    //openfile
    infile.open(filename);
    //if you cant open the file, print error message
    if (!infile)
    {
        cerr<< "Cannot open " <<filename << endl;
        exit(1);
    }

    	//Read the file 
		while(!((infile >> num)==NULL))//check for EOF
		{ 
        numbers[count++] = num; // load contents of file into your int array
		}	
		infile.close();
		return(0);
}

And your bounds check would be:

Code:

 //Read the file 
while((!((infile >> num)==NULL)) && count < 21)//check for EOF and bounds check for array numbers
{ 
        numbers[count++] = num; // load contents of file into your int array
}

This will read your file into the array numbers.